Dit is ons nieuw hondje Kira, een kruising van een waterhond en een Podenko. Ze is sinds 7 februari 2024 bij ons en druk bezig ons hart te veroveren. Het is een lief, aanhankelijk hondje, dat zich op een week snel aan ons heeft aangepast. Ze is heel vinnig en nieuwsgierig, een heel ander hondje dan Noleke.
This is our new dog Kira, a cross between a water dog and a Podenko. She has been with us since February 7, 2024 and is busy winning our hearts. She is a sweet, affectionate dog who quickly adapted to us within a week. She is very quick and curious, a very different dog than Noleke.
DEAR VISITOR,
MY BLOG EXISTS NEARLY 13 YEARS AND 4 MONTH.
ON /30/09/2024 MORE THAN 2.230.520
VISITORS FROM 135 DIFFERENT NATIONS ALREADY FOUND THEIR WAY TO MY BLOG.
THAT IS AN AVERAGE OF 400GUESTS PER DAY.
THANK YOU FOR VISITING MY BLOG AND HOPE YOU ENJOY EACH TIME.
The purpose of this blog is the creation of an open, international, independent and free forum, where every UFO-researcher can publish the results of his/her research. The languagues, used for this blog, are Dutch, English and French.You can find the articles of a collegue by selecting his category. Each author stays resposable for the continue of his articles. As blogmaster I have the right to refuse an addition or an article, when it attacks other collegues or UFO-groupes.
Druk op onderstaande knop om te reageren in mijn forum
Zoeken in blog
Deze blog is opgedragen aan mijn overleden echtgenote Lucienne.
In 2012 verloor ze haar moedige strijd tegen kanker!
In 2011 startte ik deze blog, omdat ik niet mocht stoppen met mijn UFO-onderzoek.
BEDANKT!!!
Een interessant adres?
UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN - DE ALLERLAATSTE NIEUWTJES
UFO's of UAP'S in België en de rest van de wereld In België had je vooral BUFON of het Belgisch UFO-Netwerk, dat zich met UFO's bezighoudt. BEZOEK DUS ZEKER VOOR ALLE OBJECTIEVE INFORMATIE , enkel nog beschikbaar via Facebook en deze blog.
Verder heb je ook het Belgisch-Ufo-meldpunt en Caelestia, die prachtig, doch ZEER kritisch werk leveren, ja soms zelfs héél sceptisch...
Voor Nederland kan je de mooie site www.ufowijzer.nl bezoeken van Paul Harmans. Een mooie site met veel informatie en artikels.
MUFON of het Mutual UFO Network Inc is een Amerikaanse UFO-vereniging met afdelingen in alle USA-staten en diverse landen.
MUFON's mission is the analytical and scientific investigation of the UFO- Phenomenon for the benefit of humanity...
Je kan ook hun site bekijken onder www.mufon.com.
Ze geven een maandelijks tijdschrift uit, namelijk The MUFON UFO-Journal.
Since 02/01/2020 is Pieter ex-president (=voorzitter) of BUFON, but also ex-National Director MUFON / Flanders and the Netherlands. We work together with the French MUFON Reseau MUFON/EUROP.
ER IS EEN NIEUWE GROEPERING DIE ZICH BUFON NOEMT, MAAR DIE HEBBEN NIETS MET ONZE GROEP TE MAKEN. DEZE COLLEGA'S GEBRUIKEN DE NAAM BUFON VOOR HUN SITE... Ik wens hen veel succes met de verdere uitbouw van hun groep. Zij kunnen de naam BUFON wel geregistreerd hebben, maar het rijke verleden van BUFON kunnen ze niet wegnemen...
16-11-2018
Colonizing Mars Means Contaminating Mars — And Never Knowing For Sure If It Had Its Own Native Life
Colonizing Mars Means Contaminating Mars — And Never Knowing For Sure If It Had Its Own Native Life
By David Weintraub, Vanderbilt University
The closest place in the universe where extraterrestrial life might exist is Mars, and human beings are poised to attempt to colonize this planetary neighbor within the next decade. Before that happens, we need to recognize that a very real possibility exists that the first human steps on the Martian surface will lead to a collision between terrestrial life and biota native to Mars.
If the red planet is sterile, a human presence there would create no moral or ethical dilemmas on this front. But if life does exist on Mars, human explorers could easily lead to the extinction of Martian life. As an astronomer who explores these questions in my book "Life on Mars: What to Know Before We Go," I contend that we Earthlings need to understand this scenario and debate the possible outcomes of colonizing our neighboring planet in advance. Maybe missions that would carry humans to Mars need a timeout.
Where life could be
Life, scientists suggest, has some basic requirements. It could exist anywhere in the universe that has liquid water, a source of heat and energy, and copious amounts of a few essential elements, such as carbon, hydrogen, oxygen, nitrogen and potassium.
Mars qualifies, as do at least two other places in our solar system. Both Europa, one of Jupiter's large moons, and Enceladus, one of Saturn's large moons, appear to possess these prerequisites for hosting native biology.
I suggest that how scientists planned the exploratory missions to these two moons provides valuable background when considering how to explore Mars without risk of contamination.
Below their thick layers of surface ice, both Europa and Enceladus have global oceans in which 4.5 billion years of churning of the primordial soup may have enabled life to develop and take root. NASA spacecraft have even imaged spectacular geysers ejecting plumes of water out into space from these subsurface oceans.
To find out if either moon has life, planetary scientists are actively developing the Europa Clipper mission for a 2020s launch. They also hope to plan future missions that will target Enceladus.
Taking care to not contaminate
Since the start of the space age, scientists have taken the threat of biological contamination of other worlds seriously. As early as 1959, NASA held meetings to debate the necessity of sterilizing spacecraft that might be sent to other worlds. Since then, all planetary exploration missions have adhered to sterilization standards that balance their scientific goals with limitations of not damaging sensitive equipment, which could potentially lead to mission failures. Today, NASA protocols exist for the protection of all solar system bodies, including Mars.
Since avoiding the biological contamination of Europa and Enceladus is an extremely well-understood, high-priority requirement of all missions to the Jovian and Saturnian environments, their moons remain uncontaminated.
NASA's Galileo mission explored Jupiter and its moons from 1995 until 2003. Given Galileo's orbit, the possibility existed that the spacecraft, once out of rocket propellant and subject to the whims of gravitational tugs from Jupiter and its many moons, could someday crash into and thereby contaminate Europa.
Such a collision might not occur until many millions of years from now. Nevertheless, though the risk was small, it was also real. NASA paid close attention to guidance from the National Academies' Committee on Planetary and Lunar Exploration, which noted serious national and international objections to the possible accidental disposal of the Galileo spacecraft on Europa.
To completely eliminate any such risk, on Sept. 21, 2003, NASA used the last bit of fuel on the spacecraft to send it plunging into Jupiter's atmosphere. At a speed of 30 miles per second, Galileo vaporized within seconds.
Mars is the target of seven active missions, including two rovers, Opportunity and Curiosity. In addition, on Nov. 26 NASA's InSight mission is scheduled to land on Mars, where it will make measurements of Mars' interior structure. Next, with planned 2020 launches, both ESA's ExoMars rover and NASA's Mars 2020 rover are designed to search for evidence of life on Mars.
The good news is that robotic rovers pose little risk of contamination to Mars, since all spacecraft designed to land on Mars are subject to strict sterilization procedures before launch. This has been the case since NASA imposed "rigorous sterilization procedures" for the Viking Lander Capsules in the 1970s, since they would directly contact the Martian surface. These rovers likely have an extremely low number of microbial stowaways.
Any terrestrial biota that do manage to hitch rides on the outside of those rovers would have a very hard time surviving the half-year journey from Earth to Mars. The vacuum of space combined with exposure to harsh X-rays, ultraviolet light and cosmic rays would almost certainly sterilize the outsides of any spacecraft sent to Mars.
Any bacteria that sneaked rides inside one of the rovers might arrive at Mars alive. But if any escaped, the thin Martian atmosphere would offer virtually no protection from high energy, sterilizing radiation from space. Those bacteria would likely be killed immediately. Because of this harsh environment, life on Mars, if it currently exists, almost certainly must be hiding beneath the planet's surface. Since no rovers have explored caves or dug deep holes, we have not yet had the opportunity to come face-to-drill-bit with any possible Martian microbes.
Given that the exploration of Mars has so far been limited to unmanned vehicles, the planet likely remains free from terrestrial contamination.
But when Earth sends astronauts to Mars, they'll travel with life support and energy supply systems, habitats, 3D printers, food and tools. None of these materials can be sterilized in the same ways systems associated with robotic spacecraft can. Human colonists will produce waste, try to grow food and use machines to extract water from the ground and atmosphere. Simply by living on Mars, human colonists will contaminate Mars.
Can't turn back the clock after contamination
Space researchers have developed a careful approach to robotic exploration of Mars and a hands-off attitude toward Europa and Enceladus. Why, then, are we collectively willing to overlook the risk to Martian life of human exploration and colonization of the red planet?
Contaminating Mars isn't an unforeseen consequence. A quarter century ago, a National Research Council report entitled "Biological Contamination of Mars: Issues and Recommendations" asserted that missions carrying humans to Mars will inevitably contaminate the planet.
I believe it's critical that every attempt be made to obtain evidence of any past or present life on Mars well in advance of future missions to Mars that include humans. What we discover could influence our collective decision whether to send colonists there at all.
Even if we ignore or don't care about the risks a human presence would pose to Martian life, the issue of bringing Martian life back to Earth has serious societal, legal and international implications that deserve discussion before it's too late. What risks might Martian life pose to our environment or our health? And does any one country or group have the right to risk back contamination if those Martian lifeforms could attack the DNA molecule and thereby put all of life on Earth at risk?
But players both public – NASA, United Arab Emirates' Mars 2117 project – and private – SpaceX, Mars One, Blue Origin – already plan to transport colonists to build cities on Mars. And these missions will contaminate Mars.
Does humanity have an inalienable right to colonize Mars simply because we will soon be able to do so? We have the technology to use robots to determine whether Mars is inhabited. Do ethics demand that we use those tools to answer definitively whether Mars is inhabited or sterile before we put human footprints on the Martian surface?
This article is republished from The Conversation under a Creative Commons license. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher.
À la suite de l'appel à témoins publié le dimanche 14 octobre, La Rep' compile, depuis, des témoignages tous plus édifiants les uns que les autres, à propos de mystérieuses lumières se déplaçant la nuit dans le ciel. Comment mettre en doute la sincérité des témoins quand ceux-ci sont désormais plus de 200 à évoquer les mêmes apparitions, partout dans le Loiret ?
Que se passe-t-il dans le ciel du Loiret, et son horizon bas, depuis cet été ? Après trois premières observations pour le moins intrigantes réalisées depuis Orléans, l’appel à témoins de La Rep’ publié dimanche 14 octobre a rencontré une somme relativement inédite de témoins du phénomène, que l’on ne peut définir, pour l’heure, autrement sous le terme d'"Ovni". Faute de connaître l'origine de ces mystérieuses apparitions célestes. Des Objets volants non-identifiés, donc.
Parole qui se libère (« J’avais un peu peur d’être pris pour un fou » ; « ça me rassure de constater que je ne suis pas la seule à avoir vu »), les témoins décident finalement de partager leurs observations, parfois à plusieurs reprises, au-dessus de leur quartier, des cultures ou de la forêt... Précisons qu'entre 150 et 200 mails nous ont été envoyés (en plus de dizaines de coups de fil), parfois avec photos, vidéos (prises de nuit, d'où leur caractère d'imperfection)... Nous vous en livrons quelques-unes ci-dessous.
Ajoutons seulement à l'attention des sceptiques - au point de vue tout aussi respectable - que, face à tant de témoignages émanant de gens ne se connaissant pas, se sentant obligés de se définir en préambule de "sérieux", et rapportant souvent avoir vu la même chose dans la nuit, on ne peut balayer d'un revers de la main le caractère de sincérité général. Très peu se risquent par ailleurs à avancer une piste extraterrestre. Même si elle peut parfois brûler certaines lèvres...
Comme celles de ce couple du petit village de Gy-les-Nonains (Gâtinais). Celui-ci jure avoir vu de jour, et c'est là l'un des seuls témoignages du genre, entre 15 heures et 15h15, "trois énormes boules lumineuses aller et venir dans le ciel. D'en bas, c'était dix fois plus gros qu'un avion de ligne". L'observation aurait eu lieu le vendredi 5 octobre.
Des sphères lumineuses en formation
Reste qu'il convient à présent de regarder froidement la réalité en face, et de laisser la place aux autres récits (parus dans nos éditions papier du mercredi 24 octobre, NDLR), avec cette question : mais que voient, depuis au moins cet été, les Loirétains dans leur ciel ? Une synthèse des dizaines de mails envoyés à notre rédaction, et aussi des commentaires laissés sur Facebook, permettent de définir très schématiquement les curieuses manifestations, intervenant plutôt dans le jour naissant, entre 6 heures et 7h30 (mais avant, on est au lit) ou à la tombée de la nuit (mais après, on dort).
Sont ainsi évoquées des boules de lumière extrêmement brillantes, qui se déplaceraient en général en formation de trois ou quatre. Deux des sphères sont souvent considérées par les témoins comme solidaires, en ce sens que leurs trajectoires semblent exactement les mêmes, "comme si un fil invisible les reliait". La dernière boule - quand elles sont bien trois -, parfois rouge, aurait, elle, plutôt tendance à incarner l'électron libre dans la nuit d'automne.
À Ingré, Richard, un retraité, précise, en préambule, ne pas être "le perdreau du coin". À deux reprises, le soir du vendredi 12 et samedi 13 octobre au petit matin, il voit les lumières au-dessus des champs de blé derrière chez lui. "Les drones de Bricy, que je connais bien pour habiter près de la base, étaient tout autour.Tout se passait peut-être entre 200 et 900 mètres d’altitude, enfin, c'est difficile à estimer. Reste que c’était l’affolement là-haut. Est-ce que l'on teste un nouvel engin militaire derrière chez moi ?", interroge l'homme de 73 ans. Une chose est sûre, précise-t-il, "je ne m'explique pas ce que j'ai vu, à quatre reprises en tout. J'ai vu partir ces boules de lumière à l'horizontale, c'était comme des comètes au-dessus des maisons, mais qui ne venaient pas du ciel. Elles laissaient une longue traînée orangée derrière elles, et rien de ce que je connais sur terre ne peut se déplacer à cette vitesse. Je peux vous dire que les drones ne suivaient pas, c'était bien trop rapide, 100, 200 fois plus qu'un avion de chasse".
Phénomène observé partout dans le Loiret
Celui de Richard constitue l'un des témoignages les plus saisissants, mais ils viennent de partout : Orléans, Saint-Jean-de-Braye, Saint-Jean-de-la-Ruelle, Saint-Jean-le-Blanc, Mardié, Pithiviers, Bouzonville-aux-Bois, Souppes-sur-Loing, Montargis, Lamotte-Beuvron, Etampes (91), Amilly, Corquilleroy, Gy-les-Nonains, La Ferté-Saint-Aubin, Vienne-en-Val, Saint-Lyé, Neuville-aux-Bois, Viglain ou encore Mézières-les-Cléry...
"Fin septembre-début octobre, vers 22 heures, à Vienne-en-Val, ma femme et moi-même avons vu une lumière rouge et deux blanches se déplaçant très rapidement du nord au sud. Elles étaient visibles côté est de notre village. J'ai d'abord pensé à un aéronef, malgré une vitesse exceptionnelle, mais ça a traversé l'horizon en huit ou dix secondes", décrit cet autre témoin.
Tout autant troublé que Richard par la vitesse de déplacement phénoménale observée. Et Richard de préciser : "Je connais bien le ciel pour l’observer depuis 50 ans. Je sais reconnaître une météorite, un avion de ligne, la station spatiale ou une étoile filante... Mais là, les trajectoires ne correspondent pas, et puis, on dirait que ça vient d'en bas…"
"Est-ce bien humain ?", interroge Jacques, de Marigny.
"Rien ne peut aller aussi vite. En un battement de cils, les lumières sortent de l’horizon", rapporte Jessica, de Viglain.
"C’est là pour être vu"
Une chose sur laquelle beaucoup s’accordent cependant : "Quelle que soit l’origine du phénomène, militaire ou autre, une chose semble évidente, c’est là pour être vu", en déduit cet habitant de Neuville-aux-Bois.
Une petite dizaine de groupes d'ufologues (de toute la France) ont déjà contacté notre rédaction, à la suite de l'appel à témoin. L'un d'eux aura eu cette réflexion : "Vous tenez peut-être là, dans le Loiret, quelque chose d’énorme."
Énorme ou pas, l'Orléanais Thierry, le premier à s'être signalé à La Rep', après quinze jours d'observation des lumières dans l'horizon depuis son immeuble du quartier Saint-Marceau, dit désormais "peiner à trouver le sommeil. Je n'arrête pas d'y penser depuis". Et de se dire "émerveillé", quandd'autres témoins confient plutôt leur angoisse, après avoir vu les lumières.
Le témoignage le plus édifiant
C'est le cas de l'Orléanaise K., que nous avons eu au téléphone la semaine dernière. Son récit est proprement édifiant : "J'habite le quartier Barrière-Saint-Marc. Dans la nuit de dimanche à lundi, je dormais, quand, après deux heures du matin, une lumière extraordinaire a percé à travers ma fenêtre de toit. J'ai d'abord cru à un incendie, raconte-t-elle, encore paniquée. Je l'ai donc ouverte, et ai passé la tête dehors. Au-dessus de chez moi, il y avait cette forme triangulaire avec des lumières dessous. Vertes et rouges, je crois. J'ai eu la peur de ma vie, j'étais comme paralysée. Que se passe-t-il ? Tout s'est arrêté quand c'est parti en direction de l'ouest à une vitesse fulgurante." Des larmes dans la voix, K. affirme, depuis, souffrir de maux de tête et de vomissements. Mardi, elle se décidait à aller consulter un généraliste. Son témoignage est le seul du genre. Édifiant au point que l'on comprendra aisément que beaucoup ne lui apportent que peu de crédit. Il n'en demeure pas moins que la sincérité de K. transparaissait dans sa voix, ses tremblements et interrogations. Précisons seulement que K. n'est pas la première personne à évoquer un triangle dans la nuit. Les témoignages sont certes rares à l'échelle du Loiret, mais ils existent.
Triangles noirs et centrale survolée
Ce que confirme le chercheur strasbourgeois, et chef d'entreprise, Silvano Trotta :"La présence dans le monde de triangles noirs avec quatre lumières dessous capables de s'en détacher est observée depuis au moins 1936, rapporte le chercheur américain au Mufon, David B. Marler." Il précise : "Marler observe que ces ovnis ont toujours affiché des attributs physiques et une dynamique de vol similaires. Ce qui vient contredire fortement l'idée qu'ils peuvent être un nouvel engin militaire, vu qu'on les observe depuis 80 ans."
La semaine dernière, La Rep' a envoyé des photos à Silvano Trotta : celles qu'un Loirétain assure avoir prises aux abords de la centrale nucléaire de Saint-Laurent-des-Eaux (Loir-et-Cher).
Sphère aperçue, de jour, au-dessus du Centre-Val de Loire et de la centrale de Saint-Laurent-des-Eaux. Cette image du Loirétain David Godet "est authentique à 99%", selon des chercheurs, à qui nous l'avons envoyée cette semaine.
Le chercheur Silvano Trotta les a donc faites analyser. Ses conclusions sont les suivantes : "Elles sont à 99 % tout à fait authentiques". Précisons que Silvano travaille avec des ingénieurs qui ont rentré les images dans un logiciel de contrôle de leurs pixels. Le but : vérifier si elles sont truquées ou non. Celles-ci ne le seraient donc pas.
D'où la question : qu'est-ce qui survole la centrale nucléaire de Saint-Laurent ? Sommes-nous en présence d'un drone ? "Cela pourrait effectivement être un drone militaire, voire étranger, que l'on ne connaît pas, ajoute Silvano. Mais quel intérêt auraient les Russes ou les Chinois à survoler une vieille centrale nucléaire française ?"
La sphère en question semble identique en tout points et se comporter dans le ciel de la même façon que les lumineuses, observées, de nuit, au-dessus du Loiret par des centaines d'habitants. "Le phénomène semble effectivement s'intensifier depuis plusieurs semaines, et à l'échelle de toute la France," ajoute Jean-Louis Lagneau, à la tête de la revue ufologique LDLN, Lumières dans la nuit.
Il précise : "Des abonnés du Loiret m'avait, avant votre appel à témoins, déjà fait remonter leurs observations, notamment dans la région de Pithiviers et de la commune de Sury-aux-Bois".
Inquiétude et dérision
Un ultime ufologue entré en contact avec notre rédaction aura eu ces mots : "Personne n'est aujourd'hui en mesure de dire de quoi il s'agit, ce qui survole manifestement votre département, et plus largement la France, c'est le grand mystère. Mais il faut en parler, car j'observe que de plus en plus de personnes sont témoins des lumières, et qu'il s'installe une certaine inquiétude un peupartout. Le sujet des Ovnis est généralement tourné en dérision quand on l'évoque, et pas qu'en France. Allez à la télévision en parler sérieusement et il y aura, en général, un type déguisé en alien sur le plateau. Ce n'est pas bien, c'est une façon de faire diversion, de tourner les choses en dérision. On est pourtant là sur un sujet sérieux, et ça commence à se voir. Il n'y a qu'à observer ce qui se passe chez vous, dans le Loiret".
La base aérienne de Bricy contactée
Nous avons contacté la base de Bricy (le mercredi 17 octobre) pour savoir notamment si ses radars n'avaient pas détecté une activité aérienne pouvant sortir de l'ordinaire, ou un peu extraordinaire. La réponse est "non". "Aucune activité particulière n'a été repérée." Et la cellule communication de la base aérienne 123 de préciser que celle-ci n'abrite pas de drones, en référence à cet Ingréen affirmant en avoir vus dans le périmètre de sa maison, autour des sphères lumineuses.
The historic neutron-star crash that astronomers observed last year didn't generate a black hole after all, at least not initially, a recent study suggests.
In October 2017, researchers announced that they had detected both light and gravitational waves — the ripples in space-time first predicted by Albert Einstein a century ago — emanating from themerger of two superdense stellar corpsesknown as neutron stars.
This epic collision — called GW170817, because it was first spotted on Aug. 17, 2017 — marked the beginning of the era of "multimessenger astrophysics," astronomers said. This term refers to the study of a cosmic object or phenomenon using at least two different types of signals. [Neutron-Star Crash: A Gravitational Waves Discovery in Pictures]
Data gathered by the Laser Interferometer Gravitational Wave Observatory (LIGO) project indicated that the object created by the merger was about 2.7 times more massive than the sun. That's right on the neutron star-black hole borderline, so the identity of the newly formed body was unclear: It was either the least massive black hole ever discovered, or the most massive neutron star.
Astronomers initially leaned toward the black-hole interpretation, but the recent study argues for a neutron star — specifically, a supermagnetic type known as a magnetar. That's because the authors dug a new signal out of the data collected by LIGO and its sister project, Virgo — a 5-second descending "chirp" that began after the initial round of gravitational waves, but before an accompanying burst of high-energy gamma rays.
This newly discovered chirp's frequency was less than 1 kilohertz (kHz), the study reports. That's consistent with what a magnetar should produce, and significantly lower than the minimum value expected from a roughly 3-solar-mass black hole, which should be at least 2 kHz, study team members said.
"We're still very much in the pioneering era of gravitational-wave astronomy," lead author Maurice van Putten of Sejong University in South Korea, said in a statement. "So, it pays to look at data in detail. For us this really paid off, and we've been able to confirm that two neutron stars merged to form a larger one."
The fate of the magnetar, however, is unknown. It may enjoy a long life as a fast-spinning neutron star called a pulsar, or it may eventually collapse to form a black hole, the researchers wrote in the study, which was published online in September in the journal Monthly Notices of the Royal Astronomical Society: Letters.
Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate) is out now. Follow him on Twitter @michaeldwall.
Why haven't we heard from aliens? Scientists don't know, but they have a couple of ideas — and Space.com senior writer Mike Wall tackles that question and many more in his new book "Out There: A Scientific Guide to Alien Life, Antimatter, and Human Space Travel (For the Cosmically Curious)" (Grand Central Publishing, 2018). Space.com caught up with Wall by email to talk about the book, when we'll first spot alien life and how he brought concrete, scientific answers to speculative questions.
Space.com: Why did you decide to write this book?
Mike Wall: These are very interesting times. The search for alien life has moved from the fringes to the scientific mainstream, and the private-spaceflight revolution led by companies such as SpaceX and Blue Origin is making it possible for us to think seriously about settling Mars and other worlds beyond Earth. [Read an excerpt from "Out There"]
I guess I wanted to get this sense of excitement across to readers — to let them know that they're living through an era that future generations may well regard as an inflection point in our understanding of humanity's place in the universe and our quest to get off our home planet and out into the solar system.
Space.com: Which topics did you find most fascinating to cover?
Wall: I've always been most interested in the search for alien life. It is one of the biggest unanswered questions in science, after all: Are we alone?
And there are so many secondary questions that spring from that big one. If we're not alone, then, how common is life throughout the Milky Way galaxy and the broader universe? What kinds of life are out there? Just "simple" organisms such as microbes, or technologically smart creatures capable of reaching out to us in some way? How could we find these organisms, if they exist? What kind of evidence would be needed to convince everyone (or nearly everyone; unanimity is hard to imagine) of such of an epochal find, and how would society react to the news?
Space.com: Your book deals with a lot of hypothetical situations. How did you bring the reality of existing research to bear when answering such speculative questions?
Wall: You have to extrapolate based on what happened here on Earth, because that data set is the only one we have. For example, we know that life had taken root here by about 3.8 billion years ago, which suggests that it may not be terribly tough for microbial life to get going. We also know that Earth life remained microbe only for 3 billion years after that, which seems to indicate that the jump to multicellularity may be a serious hurdle for life in general.
And it seems reasonable to suspect that alien life, if it exists, may be carbon-based and use liquid water as a solvent. That's what happened here, and complex carbon compounds and water are both incredibly common throughout the cosmos.
But you don't want to get locked in to Earth's example as the only way that things could happen. That's unjustifiable, given how little we know and the staggering diversity of alien worlds, both in our solar system and beyond. So, it's a fine line to walk — informed speculation, with an open mind. Hopefully, I've managed to stay on that line, more or less, throughout the book.
Space.com: Do you think we'll ever run into alien life? In what circumstance do you think it's most likely that will happen?
Wall: I do, and I think it will happen relatively soon. I suspect that microbial life is common throughout the cosmos. And our own solar system harbors multiple potentially habitable alien environments, from the clouds of Venus to the Martian underground to the buried oceans of the Saturn satellite Enceladus and the Jupiter moon Europa.
I think we'll find evidence of microbial life on one of these worlds in Earth's backyard in the next few decades. We might also spot biosignature gases in the atmosphere of a nearby exoplanet in roughly the same time frame. This is just a hunch, of course. But I'm optimistic.
I'm more agnostic about the discovery of intelligent alien life. That, to me, is such a crapshoot that it's hard to make any predictions about it.
Space.com: Why might intelligent aliens be keeping quiet?
Wall: I don't think there's any one answer to Fermi's Paradox; it's probably a combination of factors.
For example, I'd wager that intelligent aliens are rare throughout the cosmos, both because it's tough to make the leap from microbe to multicellular life to technologically intelligent creature, and because supersmart species may well destroy themselves once they reach a certain level of technical aptitude (the ability to build an atomic bomb and/or greatly alter their home planet's climate, for example).
And then there's the immensity of space. If "advanced" aliens are spread thinly throughout the universe, it would take a very long time for their missives or their starships to reach us, and there's no guarantee that the timing would work out. For instance, we may have gotten a ping 3 billion years ago, or 100 million years ago, or 500 years ago, and completely missed it.
And then there's the motivation question: We can't assume that every extraterrestrial civilization would want to reach out to their neighbors. Many may be keeping quiet for safety's sake, afraid of betraying their presence to colonization-minded species that could wipe them out.
Of course, the most depressing answer is the simplest one: We are alone.
Space.com: Do you think we should keep quiet as well?
Wall: This is a topic of much debate within the SETI (search for extraterrestrial intelligence) community, and I see merit on both sides. Stephen Hawking was right, of course, when he stressed that we cannot know what advanced aliens may think of us, or want to do with us. So, broadcasting signals out into the galaxy could be inviting our own destruction.
But it's also true that we've been broadcasting such signals, in a passive and diffuse way, for a century now already. So, maybe advanced aliens already know we're here, and they're just waiting for a sign that we want to talk, or that we're worth talking to — that we merit inclusion in the "Galactic Club."
I haven't completely made up my mind, but I probably lean more toward openness. Attempts to message ET have already happened, after all, and they'll doubtless continue. It's hard to keep nearly 8 billion people in line and off the airwaves.
Researchers working in China’s oldest archaeological site have discovered two human skulls featuring traces of trepanation.
The archaeological site of Yin Xu, close to Anyang City, some 500 km south of Beijing, is an ancient capital city of the late Shang Dynasty.
Image credits: UNESCO.
Trepanation, the practice of drilling hole in the skull for medical purposes, was remarkably widespread across ancient cultures. We have found evidence of trepanation from theInca peoplein South America toAncient Greece; humans were also practicing it on animals more than5,000 years ago. However, for the longest time, China seemed devoid of trepanation. A 2017 study attributes this to “the lack of publications on this topic in the English language,” and a recent finding seems to add to that idea.
Archaeologists have just uncovered two skulls, including one belonging to a 10-year-old boy, that show clear signs of trepanation.
“The skull surface is smooth and even, indicating the traces of artificial drilling. And the cranium shows that it still grew after the perforation, which suggests the surgery was successful,” said Yue Hongbin, researcher with the Institute of Archaeology under the Chinese Academy of Social Sciences (CASS), according to Xinhua.
The skulls date back to the Shang Dynasty (about 1600 BC-1046 BC), a period known for many cultural and social advancements. During the Shang Dynasty, people would treat diseases with drugs, surgeries, acupuncture, and massages, said Yue.
The findings were made at a long-known site: Yin, the last capital of the Shang Dynasty, which is in the current day city of Anyang. Yin has been excavated for some 90 years, yielding numerous remarkable findings — and this one is no exception. Archaeologists have discovered a hospital or a similar medical site, it seems, which is surprisingly sophisticated for its time. They’ve uncovered inscriptions on tortoise bones, detailing the names, symptoms, and treatments of 50 kinds of diseases, says Song Zhenhao, one of the research leaders at CASS.
In a nearby tomb, archaeologists also discovered a large number of plant leaves, including some of ‘oriental bittersweet’ (Celastrus orbiculatus) — a plant that’s still used in Chinese traditional medicine to clear away toxins such as snake venom.
Archaeologists also report identifying bone needles which they believed were used for medical purposes.
“They were not needles for sewing, since they are sharp at both ends and do not have pinholes. We believe they were for medical use,” said Yue. “Archaeological findings in the ruins have continued to provide more and more evidence to help recast ancient medical history.”
It’s not clear how common trepanation was in ancient China, though it was definitely practiced at times. A recent study suggests that the practice dates back at least 3,500 years, and these new findings seem to support that timeline.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
2. Zooming In
Hiawatha Glacier was named in 1922 in honor of the native American leader who co-founded the Iroquois Confederacy. Nearly a century later, scientists using advanced technology to peer under more than half a mile (nearly a kilometer) of ice discovered a hidden crater.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
3. A Large Feature
The hidden crater stretches nearly 20 miles (31 km) wide. A prominent rim surrounds the depression.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
4. Evidence Reveals Details
A view of the bedrock below the ice facing northwest, toward the sea, shows the terrain of the crater. In addition the rim surrounding the feature, the researchers behind the discovery also spotted a slight rise in the center. Such a rise is a fairly common feature in impact craters, but not diagnostic of how the gape formed.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
5. Perspective
The Hiawatha Crater is so large that it could comfortably hold the French city of Paris within its rim.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
6. Hurtling Through Space
An artist's depiction of a large, iron-heavy meteor falling through Earth's atmosphere toward northwest Greenland.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
7. Impact!
An artist's depiction of the meteorite smashing into the Greenland ice sheet. The scientists behind the new research believe the initial impact created a hole 12 miles (20 km) across, which rapidly collapsed to form the crater left behind
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
8. Dating the Crater
The researchers who spotted the crater used radar data gathered by airplanes to study the feature. That data suggested that the impact occurred somewhere between 3 million and 12,000 years ago, after the ice sheet had already formed.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
9. Studying the Rocks
The scientists collected sediment carried out of the crater by the glacier. They looked for shocked quartz grains, which bear the traces of dramatic impact and melting from a collision.
Credit: Natural History Museum of Denmark/Cryospheric Sciences Lab/NASA Goddard Space Flight Center/Greenbelt, MD, USA
10. Collecting Evidence
Lead scientist Kurt Kjær visited the Hiawatha Glacier to collect samples in hopes of learning how the giant crater formed below Greenland's ice.
Earth hides its scars well; the planet has endured countless millennia of eruptions and collisions, but scientists are still stumbling upon the evidence of all that geologic drama.
Now, one such team has announced that it spotted a scar hidden below Greenland's ice, a giant crater nearly 20 miles (31 kilometers) wide. The researchers said a giant iron meteorite likely created the mark by slamming into Earth sometime in the past 3 million years.
Other scientists aren't necessarily sold yet that a space rock created the feature. "I think that the authors have presented some intriguing evidence of a possible impact site, and I think that's the right word — intrigued," David Kring, who studies impact craters at the Lunar and Planetary Institute in Houston and who wasn't involved with the new research, told Space.com. "I'm intrigued. I'm not wholly convinced that this is an impact crater." [In Pictures: The Giant Crater Beneath Greenland Explained]
The feature in question is tucked below the edge of the ice sheet in northwest Greenland, lending a semicircular edge to the ice sheet near where a glacier called Hiawatha flows toward the sea. Looking through data originally gathered to track changes in the ice itself, scientists spotted a strangely circular feature in the bedrock, so they arranged for a high-powered ice-penetrating radar instrument to fly over the area.
That instrument's data confirmed the structure of the feature itself: a depression large enough to hold all of Paris in its embrace, with a clearly defined rim all the way around. So, scientists flew in to gather samples in person, looking for chemical fingerprints of anexotic event that could have formed the feature.
And while the glacier blocks the scientists from reaching the heart of the crater, it makes up for that inconvenience by ferrying sediment out from the site in meltwater. "It's almost like a home delivery," Kurt Kjær, lead author of the study and a geologist at the Natural History Museum of Denmark at the University of Copenhagen, told Space.com.
Among those sediments, geologists found what they believe are shocked quartz grains, the result of an impact's force abruptly melting rock. The team also analyzed the chemistry of the sample, finding an unusual fingerprint of rhodium, platinum and palladium. "We don't tend to find that in many rocks that we find on Earth," Iain McDonald, a geochemist at Cardiff University in the U.K. who conducted that analysis, told Space.com. "I'm pretty convinced by what's there."
There's another twist to the puzzle of the crater: in Kjær's own institution sits a large iron meteorite that was found about 185 miles (300 km) away from the crater site. Could it be that the meteorite and crater originated from the same incoming asteroid breaking up in Earth's atmosphere as it fell to the surface? "I think it's fair to start speculating if those two are linked," Kjær said. "Maybe we found the home of this meteorite. That would be fun."
But Kring isn't as convinced as the research team that the feature actually has an extraterrestrial origin. "There are thousands, tens of thousands, maybe hundreds of thousands of circular structures on the Earth's surface," Kring said. "Almost none of them are impact craters." He said he would also like to see stronger evidence from rock analysis that the feature was truly caused by an impact, rather than by some other process. [Photos: Hunting Meteorites from Florida Fireball in Osceola]
He said he's particularly struck by the apparent lack of any measurable climate upheaval that such a large impact would have caused. The team wants to narrow down the date more precisely with future research but is confident that the crater formed between 3 million and 12,000 years ago, likely on the later end of that range. "It certainly should have created global effects, and we just have no hint or signature of that at this time," Kring said.
(Kjær said that, depending on when precisely the feature formed, it may match the sharp cooling of the Younger Dryas period, which ended about 11,500 years ago, but that it's certainly too early to say.)
Geomorphological and glaciological setting of Hiawatha Glacier, northwest Greenland. (A) Regional view of northwest Greenland. Inset map shows location relative to whole of Greenland. Magenta box identifies location of panels B-D. (B) 5-m ArcticDEM mosaic over eastern Inglefield Land. Colors are ice surface velocity. Blue line illustrates an active basal drainage path inferred from radargrams. (C) Hillshade surface relief based on the ArcticDEM mosaic which illustrates characteristics such as surface undulations. Dashed red lines are the outlines of the two subglacial paleo-channels. Blue lines are catchment outlines, i.e., solid blue line is subglacial and hatched is supraglacial. (D) Bed topography based on airborne radar sounding from 1997-2014 NASA data and 2016 AWI data. Black triangles represent elevated rim picks from the radargrams and the dark purple circles represent peaks in the central uplift. Hatched red lines are field measurements of the strike of ice-marginal bedrock structures. Black circles show location of the three glaciofluvial sediment.
Credit: University of Kansas
Nevertheless, Kring said he's glad the team is pushing forward on ways to identify unknown features on Earth's surface and understand how the planet has changed over time. And if the site does indeed turn out to be an impact, studying it in more detail could offer helpful insight for planetary protection, which considers the potentially devastating effects that future impacts from the ongoing hail of planetary material could cause.
"[Asteroids] are a hazard. They are, in fact, a threat to human civilization," Kring said. "We want to better understand the consequences if or when one of those objects actually hits the Earth, and one way to do that is to go into the geological record and measure those impacts."
For Kjær, what's most exciting isn't even the dramatic collision or its potential successors — it's the act of stumbling upon something unknown. "Look here — the age of discovery is not over yet," he said. "We can still go out here and find things that we didn't see before."
The research is described in a paper published today (Nov. 14) in the journal Science Advances.
Our corner of the Milky Way is getting rather neighborly. In 2016, astronomers discovered a planet orbiting Proxima Centauri, the nearest star to our sun, just 4 light-years away. Now, they believe they have found an exoplanet around Barnard’s star, which at 6 light-years away is the second-closest star system. The planet—a chilly world more than three times heavier than Earth—is close enough that scientists could learn about its atmosphere with future giant telescopes. “This is going to be one of the best candidates,” says astronomer Nikku Madhusudhan of the University of Cambridge in the United Kingdom, who was not part of the discovery team.
Barnard’s star b, as the new planet is called, was excruciatingly difficult to pin down, and the team is referring to it as a “candidate planet” though it is confident it’s there. Most exoplanets, including the thousands identified by NASA’s recently retired Kepler space telescope, were found using the “transit” technique: looking for a periodic dip in starlight as a planet passes in front. But that method detects only the small fraction of planets that cross their star’s face when viewed from Earth. Despite decades of watching, astronomers haven’t detected any planets transiting Barnard’s star.
But astronomers can also look for planets by measuring their gravitational tug on a star. Hundreds of exoplanets have been found by looking for periodic Doppler shifts in the frequency of starlight. In 2015, astronomers saw hints of such shifts in the light from Barnard’s star. “Then we went hard for it,” says astronomer Ignasi Ribas of the Institute of Space Sciences in Barcelona, Spain, who led the new project.
His team made observations from two ground-based telescopes in Chile and Spain. They also observed with a spectrograph at Spain’s Calar Alto Observatory and added in archival data spanning 20 years from those and four other instruments, giving them a total of nearly 800 measurements. “It was a community effort,” Ribas says. As they report today in Nature, they found that the star’s light oscillated every 233 days, implying a planet orbiting with a 223-day year.
There’s a chance that the oscillations are caused by something that affects the way the star shines in a periodic way, such as star spots. The team has calculated that this is highly unlikely, although still possible. “We’re quite convinced” it is a planet, Ribas says. Madhusudhan isn’t quite so certain: “If confirmed, this will be very good. It shows how hard it is to do this thing.”
From this orbital information, the team calculates the planet must weigh at least 3.2 times as much as Earth. That puts Barnard’s star b squarely into a terra incognita between small rocky planets like Earth and larger gas planets like Neptune. The Kepler mission has shown that such intermediate planets are common across the galaxy, but with no examples among our eight home planets, astronomers have few ideas what they are like. Are they rocky super-Earths, or gaseous mini-Neptunes? “We just don’t know. It’s really hard to tell,” Ribas says.
Finding out more about Barnard’s star b will likely require telescopes able to detect light from the planet itself. That’s hard to do because, viewed from Earth, the planet is close to the star and swamped by its glare. A few telescopes with coronagraphs—devices for masking a star’s light—have directly imaged a few large planets in wide orbits, but something like Barnard’s star b will require the greater resolution of giant telescopes coming in the next decade, such as Europe’s 39-meter Extremely Large Telescope. Observations from these scopes could reveal the planet’s rotation rate, the composition and thickness of its atmosphere, and whether it has clouds. “This would be a dream. We would learn so much about this planet,” Ribas says.
Even if Barnard’s star b is rocky, life would have a hard time taking root on its chilly surface. Although the planet orbits its star much closer than Earth does to the sun, Barnard’s star, a red dwarf, is so dim that its planet gets only 2% of the energy that Earth does. The team estimates surface temperatures of –170°C.
Madhusudhan thinks the result is a sure sign that astronomers will soon find other arrivistes to the stellar neighborhood. “I’m willing to guess there are lots like this nearby,” he says. “The question is, how do we detect them?”
*Correction, 15 November, 9:50 a.m.: This story has been updated to correct the orbital period.
L’activité des OVNI en Argentine est à l’origine d’un “CLIMAT EXTRÊME” – déclaration choc
L’activité des OVNI en Argentine est à l’origine d’un “CLIMAT EXTRÊME” – déclaration choc
Un OVNI ÉTRANGE de type orbe a été repéré en Argentine et les chasseurs d’extraterrestres pensent qu’il pourrait être à l’origine du mauvais temps dans cette région.
Une mystérieuse lumière brillante a été vue juste devant un domicile à Santa Cruz, en Argentine. La lumière étrange a été observée au cours d’une tempête, ce qui a incité certains à croire qu’elle pourrait en être la cause. L’objet semble flotter sur les lieux dans une propriété calme, et dont la finalité a provoqué l’apparition d’une multitude de théories. Certains théoriciens du complot croient que les extraterrestres sont ici sur Terre pour surveiller la race humaine, et s’amuser avec le climat car “c’est fun pour eux”.
L’éminent chasseur d’extraterrestres Scott C. Waring croit que des extraterrestres pourraient surveiller notre réaction à des scénarios météorologiques extrêmes.
Il a écrit sur son blog populaire UFO Sightings Daily : “Cet OVNI a été pris à l’extérieur d’une maison en Argentine lors d’une tempête et c’est peut-être la cause même du climat si rude de cette journée.”
“Les OVNI sont connus pour provoquer des rafales de vent, la foudre, le tonnerre, la grêle et même des tornades.”
“Pourquoi personne ne le sait encore, mais des OVNI ont été signalés lors de tels événements comme si c’était un jeu pour eux.”
“Vidéo très rare et incroyable ici.”
L’Argentine est en quelque sorte un point chaud pour les observations d’OVNI, à tel point qu’une “piste d’atterrissage” pour ovni a été construite dans la nature sauvage de l’Argentine par un homme qui prétend que des aliens lui ont demandé de créer le site.
L’étrange monument aurait été construit par un Suisse du nom de Werner Jaisli.
la piste d’atterrissage est une collection de roches blanches et brunes placées en forme d’ovniport – un monument qui ressemble à une étoile que les théoriciens du complot ont liée à une activité extraterrestre.
M. Jaisli a construit le monument dans le désert argentin juste à l’extérieur de la petite ville de Cachi dans la province de Salta.
Les plus grands monuments sont entourés de plus petits morceaux et peuvent être vus du ciel, ce qui serait pratique pour n’importe quel OVNI piloté par des extraterrestres comme ils le font près de la Terre.
Le site attire des centaines de visiteurs par an et M. Jaisli a décidé de le construire quand dit avoir reçu un “message télépathique” d’extraterrestres dans lequel ils lui ont dit qu’ils avaient besoin d’un endroit pour atterrir quand ils débarqueront sur notre planète.
Il a déclaré au journal argentin El Tribuno : “J’étais à Fuerte Alto avec mon voisin Luis. Il était minuit le 24 novembre 2008.”
“C’est une nuit d’Ovni”, j’ai dit à Luis. Et la phrase n’a pas été terminée, lorsque deux objets lumineux ont avancé d’environ 200 mètres au-dessus de la rivière Calchaquí.
“Ils étaient solides, circulaires et comme du métal bruni. Je ne sais pas pourquoi, mais mentalement je leur ai demandé de se rapprocher. Et ils l’ont fait !”
“Ils m’ont demandé par télépathie de construire l’ovniport.”
Astronomers are “99 percent confident” that this exoplanet is real and not a false detection. The planet for Barnard’s star – 2nd closest star system to our sun – appears to be a cold super-Earth.
Barnard’s star – the 2nd closest star to Earth – has a large proper motion on our sky’s dome. This image – via One-Minute Astronomer – shows its motion from 1991 to 2007. Now, this very nearby star is known to have a planet.
Astronomers have discovered thousands of exoplanets in recent years – even an Earth-sized planet orbiting the nearest star to our sun – Proxima Centauri. Today (November 14, 2018), they’re announcing another exciting finding, a super-Earth planet orbiting the closest single star (and second-closest star system) to our own sun at only six light-years away, Barnard’s Star.
The planet has been labeled Barnard’s Star b (GJ 699 b). Its discovery has been decades in the making!
Indeed, Barnard’s Star was among the first to be announced – from the early 1960s to the early 1970s – as having an orbiting planet. Astronomer Peter van de Kamp argued he saw “wobbles” in the star’s motion across our sky, indicating one or more planets tugging on the star. He was in error, with the apparent positional shifts apparently caused by adjustments in the telescope lens, but the mystique of Barnard’s Star endured.
That mystique, and the nearness of this star to Earth, must have helped encourage an international team of astronomers to work hard to find a planet for Barnard’s Star. The team – including astronomers from the European Southern Observatory (ESO), the Carnegie Institution for Science and elsewhere – has published its paper announcing the discovery in the peer-reviewed journal Nature.
The astronomers found the planet via the same method van de Kamp used in the 1960s and ’70s – which is called the radial velocity method – aided by instruments with vastly greater power and sensitivity, plus modern computers. The new planet for Barnard’s Star was found by analyzing 20 years of combined data from various telescopes, stitched together to create an exceptionally large database. According to lead author Ignasi Ribas of Spain’s Institute of Space Studies of Catalonia:
We used observations from seven different instruments, spanning 20 years of measurements, making this one of the largest and most extensive datasets ever used for precise radial velocity studies. The combination of all data led to a total of 771 measurements – a huge amount of information!
And, indeed, Barnard’s Star b is the smallest and most distant planet from its star to be found so far using radial velocity.
Our sun’s closest neighbors among the stars, including Barnard’s Star.
The radial velocity technique relies on the fact that a planet’s gravity causes tiny wobbles in the orbit of its star. The technique is based on the fact that not only does the star’s gravity affect any orbiting planets, but those planets can also affect the star, albeit to a much lesser degree.
This technique has been used to find hundreds of planets. We now have decades of archival data at our disposal. The precision of new measurements continues to improve, opening the doors to new parameters of space, such as super-Earth planets in cool orbits like Barnard’s Star b.
Astronomers are confident that the planet is real and not a false detection. Ignasi Ribas commented:
After a very careful analysis, we are over 99 percent confident that the planet is there. However, we’ll continue to observe this fast-moving star to exclude possible, but improbable, natural variations of the stellar brightness which could masquerade as a planet.
Barnard’s Star is a red dwarf star. It’s small; here’s its size compared to that of our sun and Jupiter, our solar system’s largest planet.
Barnard’s Star b appears to be a super-Earth – a type of exoplanet that is larger than Earth but smaller than Uranus or Neptune. It has a mass 3.2 times that of Earth and orbits its star every 233 days. At that distance, because the star is smaller and cooler than our sun – only emitting 0.4 percent of our sun’s radiant energy – the planet is colder than Earth, with an estimated surface temperature of -238 degrees Fahrenheit (-150 degrees Celsius). This makes it unlikely to be habitable, although little is known still about specific conditions on the planet.
We have all worked very hard on this breakthrough. This discovery is the result of a large collaboration organized in the context of the Red Dots project, which included contributions from teams all over the world. Follow-up observations are already underway at different observatories worldwide.
These astronomers also note that, since the planet is close, it will be an ideal target for NASA’s upcoming Wide Field Infrared Survey Telescope (WFIRST). It might also be possible to observe Barnard’s Star via the European Space Agency’s Gaia mission, whose second data release earlier this year has yielded a huge bounty of new and exciting insights in astronomy.
Artist’s concept of the surface of the newly discovered planet, called Barnard’s Star b.
At six light-years away, Barnard’s Star is the closest single star to our sun, but fourth closest star overall, after the three stars that make up the Alpha Centauri triple-star system, which includes Proxima Centauri. It is a red dwarf star, known to produce some flaring, but less active than most other known red dwarfs in terms of stellar flare activity. Like red dwarfs generally, this star is smaller – and believed to be older – than our sun.
Even though it is the second-closest star system, Barnard’s Star is too faint to be seen with the human eye.
The star is named for Yerkes Observatory astronomer E. E. Barnard, who was the first to notice its large proper motion – or sideways motion on our sky’s dome – in 1916. The large proper motion of Barnard’s Star is caused in part by the star’s nearness to Earth, but also by the fact that Barnard’s Star – and its newly found planet – are merely passing through our neighborhood of space, as opposed to moving in the same general stream as our sun and other nearby stars around the galaxy’s center. Over the long course of astronomical time, Barnard’s Star will move farther away!
Barnard’s Star b is a super-Earth, like Kepler-62f. This picture is an artist’s concept.
Image via NASA Ames/JPL-Caltech/T. Pyle.
Bottom line: The discovery of a super-Earth exoplanet so close to our solar system is exciting, even if the planet is unlikely to be habitable. The fact that many such worlds have already been found, and now this one so close by, means that they must likely be common throughout the galaxy, increasing the chances that some of them, or their Earth-sized cousins, could indeed support life.
WETENSCHAPDe legende van het paard van Troje is wereldberoemd, maar het verhaal van verloren stad Tenea is minder bekend. Geen wonder want archeologen twijfelden over het bestaan ervan. Tot nu. Recente vondsten verraden het weemoedige verhaal van een groep buitenstaanders die verbannen werd naar het zuiden van Oud Korinthe.
Volgens de legende wisten de Grieken Troje te veroveren met een geniepige list. Ze bouwden een reusachtig houten paard waarin soldaten zich verstopten. Dat paard haalden enkele nietsvermoedende inwoners naar binnen waarna de Grieken tevoorschijn kwamen en de stad veroverden.
Wat er met de oorspronkelijke inwoners van Troje gebeurde, wordt meestal achterwege gelaten in de Griekse mythologie. Velen wachtten immers een gruwelijk lot, anderen werden volgens historische verhalen verbannen naar de verloren stad Tenea. En recente vondsten bevestigen die verhalen. Dat kondigde het Grieks ministerie van Cultuur aan.
De eerste inwoners van de stad waren Trojaanse krijgsgevangen die verbannen werden uit eigen stad, maar wel toestemming kregen van de bezetter om een nieuw stadje te bouwen. En dat deden ze met succes want Tenea transformeerde van een plek voor buitenstaanders naar een stad met een eigen regering. Het is overigens de enige stad die ongedeerd werd gelaten na de inval van de Romeinen.
Huzarenstuk
De stad, geregeerd door oorlogsgevangenen, hield archeologen decennialang in de ban. Zeer periodieke vondsten plaagden onderzoekers en leverden beperkt bewijs van het bestaan van de stad. Zo werd er een marmeren beeld van een jongeman (Kouros van Tenea) opgegraven. Verder nog ontdekten archeologen honderden jaren geleden al een sarcofaag met het skelet van een vrouw. En de vondsten situeerden zich allemaal in de regio ten zuiden van Oud Korinthe.
Tenslotte werden archeologen in 2013 aangemoedigd om wat meer moeite te steken in de opgravingen in die regio. “Het is dankzij een plotse hoge concentratie aan keramiek en architecturale overblijfselen dat we de site ontdekten”, aldus het team Griekse archeologen. Toch konden die restanten geen hard bewijs leveren voor het bestaan van de stad Tenea, zoals die in oude verhalen omschreven wordt.
Romeins-Griekse beschaving
Gelukkig bracht de recente vondst eindelijk verlossing: de stenen muren tonen de structuur van een nederzetting die zo’n 3.000 jaar oud is. De archeologen wisten deuropeningen, muren en vloeren te onderscheiden en konden zo de mysterieuze stad een beetje minder mysterieus maken. Zo ontdekten ze ook artistieke werken waarbij de Griekse en Romeinse beschavingen samenkomen. “De overblijfselen dienden vele doelen. Een ervan was voldoen aan zowel de Griekse als de Romeinse culturele codes”, aldus de Griekse archeologen. Dat bewijst meteen dat de Romeinen het stadje van oorlogsgevangenen ongedeerd lieten in 146 voor Christus.
WETENSCHAPWetenschappers hebben onder een gletsjer in het noordwesten van Groenland een gigantische krater ontdekt. Ze denken dat die veroorzaakt is door de inslag van een meteoriet en als dat klopt, zou dat nieuw licht kunnen werpen op een controversiële theorie over het massaal verdwijnen van een heel aantal diersoorten op het einde van de laatste ijstijd.
Een verslag van de ontdekking is te lezen in het nieuwste nummer van het vakblad Science Advances. De krater zou 31 kilometer breed zijn en zo tot de 25 grootste inslagkraters op aarde behoren. Hij zou 1 kilometer onder de Hiawatha Gletsjer zitten en de eerste ooit zijn die onder ijs wordt aangetroffen.
Al in 2015 werd er voor het eerst een glimp van de krater waargenomen. Wetenschappers vlogen toen over het gebied met lasers en radars om het in kaart te brengen. Dat was een onderdeel van ‘Operation IceBridge’, van de Amerikaanse ruimtevaartorganisatie NASA.
De scans werden publiek gemaakt en een groep van Deense glaciologen – die gletsjers bestuderen – merkte iets vreemds op bij het bekijken van de data: een gigantische uitsparing in de vorm van een kom in het gesteente onder het ijs. “We vroegen ons meteen af of het een inslagkrater kon zijn”, aldus Joseph MacGregor, een van de auteurs van de paper. “We lachten eerst. Maar het kon.”
Om een nog duidelijker beeld te krijgen werden in mei 2016 nieuwe vluchten uitgevoerd over het gebied, met nieuwe en nog gevoeliger apparatuur. In juli werd er ook een grondteam op uitgestuurd dat de omliggende structuren in kaart bracht en stalen verzamelde van sediment dat van onder de gletsjer was gekomen. Daardoor kreeg het team een nog gedetailleerder beeld van de krater.
Hij bleek 320 meter diep en in het midden zat een verhoging van tussen de 50 en de 70 meter hoog. Volgens gletsjergeoloog Kurt Kjaer van de universiteit van Kopenhagen – de hoofdauteur van de studie – iets wat je kan verwachten als je aanneemt dat het om een inslag gaat. In het sediment vonden de wetenschappers ‘geschokte kwarts’, een zeldzame vorm van het mineraal die ontstaat als er erg veel energie vrijkomt. Zoals bij een inslag van een meteoriet.
Op basis van de vorm van de krater, kan hij volgens de wetenschappers veroorzaakt zijn door een meteoriet van 1 kilometer breed en 11 tot 12 ton zwaar.
Boren
De onderzoekers willen nu nog meer analyses uitvoeren op het materiaal dat ze hebben en meer materiaal verzamelen op de site zelf. In het ideale geval zouden ze dwars door de gletsjer heen kunnen boren, maar dat zou een moeilijke en dure operatie worden. Het is echter noodzakelijk als ze hun vermoedens wetenschappelijk bevestigd willen zien.
Wanneer de meteoriet precies ingeslagen kan zijn, is ook nog niet duidelijk. Ook daarvoor is meer onderzoek nodig. Op basis van de gegevens die de onderzoekers hebben, moet het gebeurd zijn toen de gletsjer er al was en zou de meteoriet een gat in het ijs geslagen hebben. “Het is waarschijnlijk minder dan 3 miljoen jaar geleden gebeurd, vermoedelijk tussen 12.000 en 15.000 jaar geleden”, aldus MacGregor.
Controversiële theorie
Als dat effectief klopt, kan dat nieuw licht werpen op een controversiële theorie – de Jonge Dryas impact hypothese – die aanvoert dat er tussen 10.900 en 12.900 jaar geleden op het einde van de laatste ijstijd een gigantische inslag plaatsvond in Noord-Amerika. Die zou grote bosbranden hebben doen ontstaan, die leidden tot het uitsterven van grote zoogdieren zoals de mammoet en de mastodont en zelfs de menselijke Cloviscultuur. Groot probleem met die theorie was tot nu toe dat er nergens een inslagkrater gevonden kon worden. Maar dat kan deze ontdekking misschien oplossen. “Het is erg speculatief”, aldus nog MacGregor. “Maar als het klopt, kan dat de menselijke geschiedenis helemaal door elkaar schudden.”
What brand of beer do extraterrestrials drink? If you’re a fan of the movie “E.T. The Extra-Terrestrial,” you might think it’s Coors, the beverage E.T. consumed a six-pack of. Of course, that was in 1982. Today, craft beers have taken over and any aliens here for a take-over might first make a stopover at a craft brewery. At least that’s what the owners of The Unknown Brewery want you to believe. They posted a picture this week of what appears to be a UFO hovering over their North Carolina facility. Did E.T. pick up another six-pack or a keg?
”Ummmm so we took a pic of a UFO last night…”
That’s the extent of the details posted on The Unknown Brewery’s Facebook page along with a picture of the alleged UFO. For skeptics who commented that it was a reflection through a car window, they pointed out that the video was taken outdoors. Surprisingly, the people standing in line, possibly waiting to get into the taproom, weren’t looking up at the UFO and the videographer didn’t point the triangle of lights out to them. If they had seen it, the fans of the brand might have recommended a spaceship-oriented brew like the Tele-Porter (a coffee porter) or the Cloudbuster (a white India pale ale).
Trying to call a UFO with beer?
“But it’s just lens reflection, mirrored about the center. You can see this by copying the lights at the top, rotating them 180 degrees, and then overlaying them on the bottom half of the image. I use a “subtract” blend mode, which makes the bright light look dark, and you can see they match exactly with the lights around the building.”
Mick West of the Metabunk.org website refused to play along and gave this explanation of how a lens reflection could be the cause, while ufoofinterest.org said simply “UFOs? Nope, massive lens flares :).” (Did they need to rub it in with a smiley?) If asked, the makers of UFO beer might wonder why the UFO wasn’t over their breweries in Boston, Massachusetts, or Windsor, Vermont.
What do they drink on the Dog Star?
Fans of Star Trek might point out that aliens wouldn’t stoop to Earth beer when they could drink Romulan ale like Captain Kirk and Dr. McCoy did in the original series (for medicinal purposes only). not be over a brewery but a distillery instead. When back on Earth, Mr. Spock might make a stop at the real place known as The Federation of Beer in Vulcan, Canada, for a glass of Vulcan Ale (“The aroma consists of sweet malts, bread, apple and some grassy hops. The flavour is of mild hops upfront, sweet apple, bread, malts, nuts and an earthiness.”) Of course, Scotty and Chekov would never drink anything but Scotch and vodka, respectively, so they’d be looking for a distillery or liquor store.
Hats off to The Unknown Brewery for their great publicity stunt. Now, to take tongue out of cheek and fill the void with some Tele-Porter.
“In the beginning,” so it is written, “God created the heavens and the earth.”
Sometime after that, humans came along in this cosmological origin story too (although I would wager that this occurred more than just a few days later, despite what the text quoted above has to say about it). Thereafter, we spent ages bumbling around on our little mudball, during which the rise and fall of chiefdoms, city-states, and civilizations occurred, along with countless wars and conflicts over land disputes, material shortages, kidnappings, killings, and the like.
At some point, things seemed to have calmed down a little–agriculture certainly helped with this, as did the formation of laws and governance–and humans finally had time to rest, and perhaps more importantly, to think. After a few thousand years of contemplation along these lines, finally, within the last few hundred years or so somebody had the idea that we might not be the only ones the Big Guy upstairs took the time to bother to create… if you prescribe to that sort of thing.
Formation of the idea that there might be inhabited worlds beyond our own first required understanding that Earth is, in fact, a round planetary body in space, and that several others exist in our cosmic neighborhood, all encircling our sun (hat tips are in order here for Galileo, Kepler, Pythagoras, Eratosthenes, and various others who contributed to such thought over the ages). In light of this, the idea of leaving Earth to visit nearby celestial bodies has actually been around for quite a while: mention of such things as travel to the moon had already been left to posterity as early as the second-century in Lucien’s satires, and a few centuries thereafter, philosophers were seriously debating the idea of whether other planets existed, and what kinds of “people” might reside there (“Cosmic Pluralism,” in other words).
By the 17th century, discussion of such likelihoods had become fairly commonplace. Eighteenth-century writers of no less esteem than Washington Irving and François-Marie Arouet (or Voltaire, as he’s better known, for those of you who slept through French Enlightenment history) had written stories where anthropomorphic “aliens” visited Earth.
There were a number of consistent themes in early science fiction writing about aliens. In particular, aliens were generally anthropomorphic (that is, they resembled humans), and were often even referred to as “people.” In fact, for some authors of alien fiction, these beings didn’t merely resemble us: visitors from other worlds actually were humans. This isn’t hard to imagine, given consideration that prior to the publication of Darwin’s The Origin of the Species in November 1859, concepts like evolution would have been remote, to say the least. In times prior to Darwin’s influence, the notion that humans were literally “made in God’s image” was more widely accepted; hence our human shape and form had been divinely inspired, not as a result of adaptations to our environment over long stretches of time.
It only stood to reason, then, that if God made us in his image, and that we lived on a planet orbiting the sun, then perhaps there were other “people” made by God, who lived elsewhere in the universe on alien planets similar to ours. Thus, the theological concept of “aliens” still entailed beings that were essentially human. Authors whose written works followed Darwin’s widespread influence reflected themes of evolution and adaptation in relation to the alien concept, such as Camile Flammarion’s 1862 work, The Plurality of Inhabited Worlds.
Decades later, H.G. Wells pointed us in a less anthropocentric direction with the octopoidal Martian invaders featured in his The War of the Worlds. The inclusion of tentacled antagonists set a new precedent for how alien life would look in the fiction of the years to come; however, rather than diversifying as Wells did, and allowing their aliens to take other unusual shapes and forms, many writers simply followed suit and incorporated tentacled, squid or octopus-like aliens into their own work (even H.P. Lovecraft, for all his imagination, appeared to strongly favor this motif). There are some notable exceptions, of course (insectoids, bodiless brains, symbiotes, robotic beings, etc), but the “tentacled alien” is a trend that nonetheless continues today, as seen in films like The Arrival and countless other stories.
Of particular interest in our brief look at the evolution of the “alien” idea is that concepts involving biological alien entities from other planets were in use for centuries before the word extraterrestrial ever came along. According to the Online Etymological Dictionary, the word extraterrestrial is defined as follows:
extraterrestrial (adj) also extra-terrestrial, “occurring or originating outside the Earth,” 1812, from extra- + terrestrial. As a noun from 1956.
While OED gives us the correct definition, there are a few things to point out about the history given here; they provide a rather obscure, earlier date of 1812 for the origin of the term (without further context or reference to where this occurred), and later its appearance as a noun in 1956. As far as finding the earliest print appearances of this expression (and specifically in relation to alien life), once again we must return to Wells, who after giving us the first non-anthropomorphic aliens in popular fiction, also seems to have been the first popular writer to gift us with a new term for them. The passage below appeared in the third chapter of The War of the Worlds, entitled “On Horsell Common,” where we can see that Wells was using the word more than half a decade earlier:
‘It required a certain amount of scientific education to perceive that the gray scale of the Thing was no common oxide, that the yellowish-white metal that gleamed in the crack between the lid and the cylinder had an unfamiliar hue. “Extra-terrestrial” had no meaning for most of the onlookers.’
It is possible that the earliest use of a non-hyphenated, nominative variant of extraterrestrial didn’t appear in print until the 1950s, although L. Sprague de Camp also appears to have used the expression in 1939 in an article, “Design for Life (Part 1 of 2),” which was first published in the May 1939 issue of Astounding Science-Fiction (this was actually one of two pieces de Camp published in that issue, although his other contribution, a short story called “Employment,” was published under a pseudonym due to the magazine’s policies against publication of more than one contribution by an individual within a single issue). It was also de Camp who first shortened Wells’ term into the popular acronym “E.T.” as seen today, and borrowed famously by Steven Speilberg for his famous film of the same name.
L. Sprague de Camp
So while it does appear that Wells was first to use the hyphenated form of the word in popular literature in 1898, there is one other noteworthy example of a similar concept that does come to mind. In the 1885 preface to his Beyond Good and Evil, philosopher Friedrich Nietzsche also uses the term “super-terrestrial,” although not in reference to the idea of biological alien life (I happened to notice Nietzsche’s use of this expression quite apart from any research for this article, and so admittedly I find it to be novel, albeit not particularly relevant to our search for the etymological origins of extraterrestrials in the English language. Also keep in mind that Nietzsche would have written the word in German, appearing as überirdischen, which directly translates to mean “unearthly,” or in the context in which he used it, might also be taken to have meant “supernatural.” In my estimation, the translation of this word into “super-terrestrial” had been a selective interpretation made by the translator, who in this case would likely have been Helen Zimmern, whose first English translation of the book appeared in 1906. Thus–spake Zarathustra?–we might even stretch a bit further to speculate that Zimmern could even have read Wells’ The War of the Worlds, and had come across his use of “Extra-terrestrial,” which for all we may know could have influenced her later translation of Nietzsche… so in essence, the point is still awarded to Wells for this one).
But why is there any need for a further distinction between “alien” and “extraterrestrial” in the first place? Actually, if we look back at Wells’ first use of the word, he wasn’t referring explicitly to a biological alien entity, per se: he had been using the term in relation to the description of “the gray scale of the Thing,” which “was no common oxide,” and also “the yellowish-white metal that gleamed in the crack between the lid and the cylinder”. In other words, Wells described the appearance of the cylindrical vessel in which the invading Martians have arrived. Quite obviously, it had been later authors that would begin to use the term in relation to alien beings themselves.
And for such authors, another reason for the “shift” might be that the word alien, in modern usage, has a variety of different meanings and interpretations. In the strictly terrestrial sense, it has relevance to things that may be seen as foreign or different to a given person or group; this has led to some problems, since the use of alien as a noun, which entails “a foreigner, someone who isn’t a naturalized citizen“ has a hard time escaping associations with its adjective form, which generally means “distasteful or odd” (one can clearly see the reasons for controversy here over its use in relation to such things as immigration, particularly in North America and parts of Europe). On the other hand, there is nothing about the word extraterrestrial that can be misconstrued as pertaining to earthly affairs.
The evolution of the extraterrestrial idea, as we can see, moved at a slow creep across the ages. Looking back over time at the conceptual development of human attitudes toward alien life is fascinating in a number of ways, and of course, far more could be said of this subject than the brief overview presented here. If anything, the gradual revelation that other forms of life could exist somewhere “out there”–and perhaps more importantly, that such a thing as “out there” existed in the first place–did more than merely introduce the concept of alien life; it caused humans to think about ourselves, our origins, and ultimately, what it actually means to be human.
Perhaps with the innovation and discovery of the coming years, we will also begin to glean some idea about what it could mean to be “extraterrestrial,” if such life from other worlds is eventually proven, without question, to exist.
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- Gemiddelde waardering: 0/5 - (0 Stemmen) Categorie:ALIEN LIFE, UFO- CRASHES, ABDUCTIONS, MEN IN BLACK, ed ( FR. , NL; E )
PILOTEN ZIEN UFO's BOVEN IERLAND 9 november 2018
PILOTEN ZIEN UFO's BOVEN IERLAND 9 november 2018
(NL ondertiteling) PILOTEN ZIEN UFO's BOVEN IERLAND 9 november 2018
Woord vooraf – Paul Harmans – ufowijzer.nl Voor alle duidelijkheid, NIEMAND weet nog wat deze snel bewegende lichten op 9 nov. 2018 in het luchtruim boven Ierland waren, dus worden ze UFO’s genoemd. Dat betekent niet meteen dat het buitenaardse toestellen zijn, maar uitsluiten kun je het op basis van het al tientallen jaren beschikbare bewijs niet.
Meteen na de meldingen van de piloten kwamen de bekende ‘leunstoel experts’ naar voren en beweerden dat het om vallende sterren ging. Vallende sterren, de naam zegt het al: ‘vallen’, en vallen doe je naar BENEDEN. In eerste instantie deden deze lichten dat ook, maar vervolgens meldt één van de piloten dat de lichten weer op zeer hoge snelheid omhoog gingen. Dat doen vallende sterren NIET!
De zwaartekracht dicteert dat alles in ons luchtruim zonder eigen voortstuwing naar het aardoppervlak valt, dus niet omhoog, maar naar BENEDEN (dat hoeft overigens niet volledig verticaal zijn). Jammer dat veel mensen de media klakkeloos geloven, alwaar dit onlogische leunstoelverhaal breed wordt gebracht als de oplossing voor de lichten die de piloten boven Ierland zagen.
Leunstoel-astronomen doen vaker volkomen onlogische beweringen als het om UFO-waarnemingen van piloten gaat. Zo beweerden zij ooit dat een Japanse piloot twee heldere planeten verwarde met een UFO. Dat de piloot meldde dat hij de UFO tegen de achtergrond van een bergketen zag, dus onder de horizon, dat deert dergelijke ‘ontkenners’ niet. De piloot meldde ook dat de UFO rondjes om zijn 747 vloog en rondom gekleurde lichten voerde en vele malen groter was dan een 747. Dat deze UFO ook werd waargenomen op de radarschermen van zowel de FAA als de luchtmacht, ach, een kleinigheidje, voor dergelijke ‘astronomische domkoppen’ verschijnen planeten blijkbaar ook op radar.
Relevante links naar mijn video's met NL ondertiteling:
Researchers recently identified a huge bowl-shaped crater measuring a staggering 19 miles (31 km) across under half a mile of Greenland ice. The immense crater was likely formed by the impact of a mile-wide iron meteorite, which must have unleashed 47,000,000 times the energy of the nuclear bomb dropped on Hiroshima at the very end of WWII. The biggest question on everybody’s mind right now is when it all happened.
Illustration of the newly-discovered immense crater in Greenland.
Credit: Nasa/Cryospheric Sciences Lab/Natural History Museum of Denmark.
Kurt Kjær, a Professor at the Natural History Museum of Denmark in Copenhagen, suspected an impact crater might be hidden away under Greenland’s ice after NASA radar images showed a massive depression of the bedrock beneath the Hiawatha glacier, in the northwestern part of the island.
In May 2016, one year after the satellite images were released, scientists flew over the glacier pointing a cutting-edge ice-penetrating radar onto the glacier to map the underlying rock. The 3-D images clearly show all the hallmarks of an impact crater — a 19.3-mile-wide circular feature with a rim around it and an elevated central region.
The crater’s basin is about 300 meters deep, suggesting it was perhaps made by a one-mile-wide meteorite. This immediately classes the impact site among the top 25 largest known craters on Earth. According to the researchers, the impact would have melted and vaporized approximately ~20 km3 of rock.
“There would have been debris projected into the atmosphere that would affect the climate and the potential for melting a lot of ice, so there could have been a sudden freshwater influx into the Nares Strait between Canada and Greenland that would have affected the ocean flow in that whole region,” co-author John Paden, Associate Professor of electrical engineering and computer science at Kansas University, told the AFP.
Kurt Kjær collecting sediment samples from the crater’s drainage system.
Credit: Natural History Museum Denmark.
The meteorite was likely mostly made of iron, judging from geochemical tests performed on particles of shocked quarts collected from a nearby floodplain.
“Beyond the grains in the sediment sample that we interpret to be possible ejecta, no ejecta layer associated with this structure has yet been identified. Despite the absence of such additional evidence, an impact origin for the structure beneath Hiawatha Glacier is the simplest interpretation of our observations,” the authors wrote in their new study.
Black triangles represent elevated rim picks from the radargrams, and the dark purple circles represent peaks in the central uplift.
Credit: Science Advances.
When exactly did the impact actually takes place is not at all certain. Kjær and colleagues are confident that the crater is no older than 3 million years, the time when ice began to cover Greenland.
“The age of this impact crater is presently unknown, but from our geological and geophysical evidence, we conclude that it is unlikely to predate the Pleistocene inception of the Greenland Ice Sheet,” the authors wrote in the journalScience Advances.
As for the lower limit, radar images show that the deepest layers of the glacier that are older than 12,000 years are very deformed compared to upper layers and are filled with lumps of rock. To be sure, researchers will have to use radiometric dating techniques on material from the crater — that means drilling through half a mile of ice. It might take a few years before this happens, however.
‘Oumuamua is the first interstellar object astronomers have detected in our solar system. For decades, scientists had been expecting to come across such an object, but it only happened in October 2017, while the Pan-STARRS 1 telescope on Haleakala, Hawaii was surveying near-Earth asteroids. Astronomers tried pointing NASA’s mighty Spitzer Space Telescope onto ‘Oumuamua, however, the comet-like object was too faint to observe directly — but this was a valuable result in and of itself.
According to a new study that worked with Spitzer data, previous estimates of ‘Oumuamua’s size have been too generous. In reality, the intriguing cosmic object is much smaller than scientists initially thought.
“‘Oumuamua has been full of surprises from day one, so we were eager to see what Spitzer might show,” David Trilling, lead author on the new study and a professor of astronomy at Northern Arizona University, said in a statement. “The fact that ‘Oumuamua was too small for Spitzer to detect is actually a very valuable result.”
Vents on the surface of the interstellar object probably emit jets of gases, propelling the object slightly. The jets were detected by measuring the position of the object as it passed by Earth in 2017.
Credit: NASA/JPL-Caltech.
Besides setting new upper and lower boundaries for the size of ‘Oumuamua (pronounced oh MOO-uh MOO-uh, meaning ‘scout’ in Hawaiian), the study also reveals new spicy details about our lone interstellar visitor. One rather amazing finding is that ‘Oumuamua is expelling gas, which acts like a small thruster pushing the small asteroid. This explains the slight changes in speed and direction of the object when scientists tracked it last year.
In the months following is discovery, astronomers conducted multiple observations with ground-based telescopes but also using NASA’s Hubble Space Telescope. These optical observations reported large variations in brightness, suggesting that ‘Oumuamua has an elongated shape, resembling a cigar, and that it probably measures less than half a mile (800 m) across its longest side.
However, Spitzer’s instruments can see things in infrared, meaning it can measure how much heat ‘Oumuamua radiates — and this can be helpful in measuring the object’s size with better accuracy than optical evaluations alone could. By measuring infrared light emitted by an object, scientists can essentially measure temperature which, in turn, can be used to determine the reflectivity of an object’s surface — what’s technically called albedo.
The new study estimates what ‘Oumuamua’s diameter would be if it were spherical. Trilling and colleagues used three separate models, each with its own different assumptions about the object’s composition but which only slightly differed from one another, and ultimately came up with three possible diameters for ‘Oumuamua: 1,440 feet (440 meters), 460 feet (140 meters) or even as small as 320 feet (100 meters).
Images of an interloper from beyond the solar system as seen on Oct. 27 by the 3.5-meter WIYN Telescope on Kitt Peak, Ariz.
Credit: WIYN OBSERVATORY/RALF KOTULLA.
The findings suggest that ‘Oumuamua may be up to 10 times more reflective than the comets we can find our solar system. A typical comet will constantly change its albedo as its ice warms and turns into gas during its close approaches to the Sun. However, ‘Oumuamua likely traveled through interstellar space for millions of years before entering our solar system, far from a star’s ‘touch’. Once it actually made it close to the sun, ‘Oumuamua’s surface likely suffered some transformations. For instance, some of the released gas may have covered the surface of the object with ice and snow that increase reflectivity.
At the moment, ‘Oumuamua is beyond Saturn’s orbit and is exiting the solar system. But scientists expect other interstellar visitors to follow. In the meantime, data gathered on the asteroid could shed light on how planet form in the solar system.
A planet three times more massive than Earth may be lurking around the second-closest star system to our cosmic neighborhood. Astronomers say they have found evidence for a so-called “super-Earth” around the famous Barnard’s star — a small, faint dwarf star located less than six light-years away. Though we don’t know what this potential planet looks like, its close proximity makes it an excellent target for future telescopes to study in the long-enduring hunt for extraterrestrial life.
Plus, a planet around Barnard’s star is one that we could see someday soon. Though we’ve found thousands of planets outside our Solar System, most of these worlds — known as exoplanets — are usually impossible to see directly with our current telescopes. They’re so far away that they become completely overwhelmed by the light from their host stars. But planets around nearby stars — like Barnard’s star — are easier for our instruments to detect. One day, we could potentially distinguish the light reflected from this planet from the light of its host star, especially as bigger and more sophisticated observatories come online in the 2020s.
“That’s the key benefit of finding a planet this close,” Ignasi Ribas, an astronomer at the Institute of Space Sciences in Spain and lead author on the study, tells The Verge. “If we ever have the hope of being able to directly image planets, it’s got to be planets that are really close by because you need to separate them from their star’s light.”
Barnard’s star has long intrigued astronomers. Because of its relatively short distance from us, it appears to be moving through the sky faster than all the other stars. The star gets its name from E. E. Barnard, the American astronomer who measured this motion in 1916. Barnard’s star is also a very small and dim type of star known as a red dwarf. In fact, it is just 14 percent the mass of our own Sun, and it’s so faint that you need a telescope to see it. Though they are among the smallest stars in the galaxy, red dwarfs are also the most common. In the past few decades, astronomers have found more and more potentially habitable planets around these celestial objects.
Because of its closeness, Barnard’s star has become a popular target for exoplanet hunters. In the 1960s, an astronomer named Peter van de Kamp claimed to have found a Jupiter-sized world around Barnard’s star after studying how the red dwarf moved. At the time, it was a big claim since we did not have good confirmation that exoplanets existed yet. But the findings were eventually refuted and blamed on issues with the telescope van de Kamp used. Over the years, astronomers have ruled out the existence of planets in the habitable zone of Barnard’s star, which is the region around a star where temperatures are just right for water to exist as a liquid.
But this time, there may actually be something in orbit around the star just a little farther out from the habitable zone. An international group of astronomers used data from 20 years of observations of Barnard’s star, taken with seven different telescopic instruments, to find clues that a planet may exist. “We put together nearly 800 observations, using the most precise instrumentation in the world just to see this small planet,” says Ribas.
Specifically, the team looked at how Barnard’s star “wobbled” over time — a technique that astronomers use to find exoplanets when they can’t be seen. Since exoplanets are drowned out by starlight, astronomers have to use clever, indirect ways to tease out the existence of a distant world. One way is to watch as these planets pass between their host star and Earth — what’s known as a transit — which slightly dims the star’s light. However, this planet does not transit, so instead, astronomers looked at how the planet’s gravity is affecting Barnard’s star. Even small planets can push and pull on a nearby star, creating tiny “wobbles” that we can measure from Earth.
Ribas and his team noticed a pattern in Barnard’s star’s wobbling within the 20 years’ worth of data, which indicated a planet revolving around the star every 233 days. They estimate the exoplanet is about 3.2 times the mass of Earth, and its distance from the star puts it in what’s known as the snow line. That’s the region around a star where gases can condense into solids and water turns into snow and ice. This area is about four times farther from the habitable zone, and many astronomers think this is the best spot around a star for planets to form. “If it’s real, then this would be a strong confirmation, one of our leading theories of planet formation,” Keivan Stassun, an astronomer at Vanderbilt University who was not involved in the study, tells The Verge.
Still, we haven’t seen this planet directly, and though Ribas is confident in his team’s findings, he admits there’s always a tiny chance that the wobbles they saw can be explained another way. “We are not 100 percent sure the signal comes from a planet, but 99.2 percent sure,” he says. “But being this confident is sufficient to claim detection of the planet.”
So the obvious next step is to get a signal from the planet itself, which may be possible soon. “At this very near distance, we should be able to separate the light from the planet from the light of the star,” says Stassun. Being able to see the light from an exoplanet is huge because then we can study what’s in the planet’s atmosphere. And the gases surrounding a planet could tell us a lot about what’s on the surface below — perhaps even indicating whether or not life is present.
Since this planet is near the snow line, it’s not a particularly promising candidate in the search for alien life. But it will be a good exoplanet for astronomers to study. It could help them refine their techniques for distinguishing planets from stars and figuring out what’s in their atmospheres. And the tools to do this should be coming online within the next decade. NASA’s James Webb Space Telescope, which is supposed to launch in 2021, should have enough sensitivity to study this planet further. And big telescopes, such as the Thirty Meter Telescope planned for Hawaii, may also be able to spot the planet.
Ribas says the best bet for seeing this world is a future telescope NASA is working on called WFIRST. The space telescope could potentially study large planets using a special instrument known as a coronagraph, which helps to block out the light of stars. Due to budget concerns, NASA has been looking at ways to reduce the cost of the coronagraph by reducing the number of masks and filters the instrument uses, according to Space News. But Ribas says a coronagraph is the most certain way to see this world. “It would be very efficient at removing the starlight,” he says. “If that kind of machinery is in place, we’ll be able to image the planet.”
For now, Ribas and his team will continue to monitor the wobbles of Barnard’s star to further strengthen their claim — one that now aligns with numerous works of science fiction. Stories like The Hitchhiker’s Guide to the Galaxy and The Garden of Rama feature planets around Barnard’s star as way stations for interstellar travelers. “It has for decades been a favorite imagined destination for human civilization at some point in the future,” says Stassun. “How tantalizing that this neighboring star is a neighboring solar system.”
SPACE ROCK An iron asteroid hurtles through space in this artist’s conception of an event that left a large crater in northwest Greenland sometime in the distant past.
NATURAL HISTORY MUSEUM OF DENMARK, CRYOSPHERIC SCIENCES LAB/GSFC/NASA
There’s something big lurking beneath Greenland’s ice. Using airborne ice-penetrating radar,scientists have discovered a 31-kilometer-wide crater — larger than the city of Paris — buried under as much as 930 meters of ice in northwest Greenland.
The meteorite that slammed into Earth and formed the pit would have been about 1.5 kilometers across, researchers say. That’s large enough to have caused significant environmental damage across the Northern Hemisphere, a team led by glaciologist Kurt Kjær of the University of Copenhagen reports November 14 in Science Advances.
Although the crater has not been dated, data from glacial debris as well as ice-flow simulations suggest that the impact may have happened during the Pleistocene Epoch, between 2.6 million and 11,700 years ago. The discovery could breathe new life into a controversial hypothesis that suggests that an impact about 13,000 years ago triggered a mysterious 1,000-year cold snap known as the Younger Dryas (SN: 7/7/18, p. 18).
Hidden bowl
A crater was discovered at the edge of Hiawatha Glacier in northwest Greenland. Airborne radar data revealed a round depression (bottom image) buried beneath almost a kilometer of ice. Researchers also found deformed quartz minerals and other signatures of an ancient impact within sediments collected just outside the edge of the ice (black circle).
K.H. KJÆR ET AL/SCIENCE ADVANCES 2018
Members of the research team first spotted a curiously rounded shape at the edge of Hiawatha Glacier in northwest Greenland in 2015, during a scan of the region by NASA’s Operation IceBridge. The mission uses airborne radar to map the thickness of ice at Earth’s poles. The researchers immediately suspected that the rounded shape represented the edge of a crater, Kjær says.
For a more detailed look, the team hired an aircraft from Germany’s Alfred Wegener Institute that was equipped with ultra-wideband radar, which can send pulses of energy toward the ice at a large number of frequencies. Using data collected from 1997 to 2014 from Operation Icebridge and NASA’s Program for Arctic Regional Climate Assessment, as well as 1,600 kilometers’ worth of data collected in 2016 using the ultra-wideband radar, the team mapped out the inner and outer contours of their target.
The object is almost certainly an impact crater, the researchers say. “It became clear that our idea had been right from the beginning,” Kjær says. What’s more, it is not only the first crater found in Greenland, but also one of the 25 or so largest craters yet spotted on Earth. And it has held its shape beautifully, from its elevated rim to its bowl-shaped depression.
“It’s so conspicuous in the satellite imagery now,” says John Paden, an electrical engineer at the University of Kansas in Lawrence and a member of the team. “There’s not another good explanation.”
On the ground, the team hunted for geochemical and geologic signatures of an asteroid impact within nearby sediments. Sampling from within the crater itself was impossible, as it remains covered by ice. But just beyond the edge of the ice, meltwater from the base of the glacier had, over the years, deposited sediment. The scientists collected a sediment sample from within that glacial outwash and several from just outside of it.
The outwash sample contained several telltale signs of an impact: “shocked” quartz grains with deformed crystal lattices and glassy grains that may represent flash-melted rock. The sample also contained elevated concentrations of certain elements, including nickel, cobalt, platinum and gold, relative to what’s normally found in Earth’s crust. That elemental profile points not only to an asteroid impact, the researchers say, but also suggests that the impactor was a relatively rare iron meteorite.
SHOCKED QUARTZ This grain of quartz shows crystal deformation that is a signature of a massive impact event.
NATURAL HISTORY MUSEUM OF DENMARK, CRYOSPHERIC SCIENCES LAB/GSFC/NASA
Determining when that iron meteorite slammed into Earth is trickier.
The ice-penetrating radar data revealed that the crater bowl itself contains several distinct layers of ice. The topmost layer shows a clear, continuous sequence of smaller layers of ice, representing the gradual deposits of snow and ice through the most recent 11,700 years of Earth’s history, known as the Holocene. At the base of that “well-behaved” layer is a distinct, debris-rich layer that has been seen elsewhere in Greenland ice cores, and is thought to represent the Younger Dryas cold period, which spanned from about 12,800 to 11,700 years ago. Beneath that Younger Dryas layer is another large layer — but unlike the Holocene layer, this one is jumbled and rough, with undulating rather than smooth, nearly flat smaller layers.
“You see folding and strong disturbances,” says study coauthor Joseph MacGregor, a glaciologist with Operation IceBridge. “And below that, we see yet deeper, complex basal ice.” Radar images of that bottommost ice layer within the crater show several curious peaks, which MacGregor says could represent material from the ground that got incorporated into the ice. “Putting that all together, what you have is a snapshot of an ice sheet that looked fairly normal during the Holocene, but was quite disturbed before that.”
Those data clearly suggest that the impact is at least 11,700 years old, Kjær says. And the rim of the crater appears to cut through a preexisting ancient river channel that must have flowed across the land before Greenland became covered with ice about 2.6 million years ago.
That time span — essentially, the entire Pleistocene Epoch — is a large range. The team is working on further narrowing the possible date range, with more sediment samples, simulations of the rate of ice flow and possibly cores collected from within the crater.
The date range does include the possibility that the impact occurred near the onset of the Younger Dryas. “It’s the woolly mammoth in the room,” MacGregor says.
HIDDEN TREASURE A newly discovered 31-kilometer-wide crater, long buried underneath Greenland’s ice sheet, may be the remnants of an iron asteroid that struck Earth sometime in the distant past.
Planetary scientist Clark Chapman of the Southwest Research Institute in Boulder, Colo., notes that “there are plenty of roughly circular landforms on Earth of many different sizes, most of which are not impact craters.” Still, he says, the paper presents several lines of evidence that strongly support the conclusion that the object is a crater, including the shocked quartz and the topography.
As for the idea that a crater may have formed within the last couple of million years, Chapman says, it’s “quite unlikely.” Such strikes are rare in general, he adds, and asteroids barreling into Earth are far more likely to land somewhere in an ocean. “[And] it would be at least a hundred times less likely that it could have happened so recently as to have affected the Younger Dryas.”
Regardless of when the crater formed, it is “a straight-up exciting discovery,” MacGregor says. “And we’re just happy not to have to keep it a secret anymore.”
µThe mysterious object appeared as a “very bright light” that came up along the left side of the airliner before it “rapidly veered to the north”.
At first, the pilot of BA94 from Montreal to Heathrow thought she might have been looking at some kind of military aircraft.
Bright lights
But she was told there were no military exercises taking place in the area and the fast-moving object did not appear on air traffic control’s radar systems.
A second pilot, flying a Virgin Atlantic plane from Orlando to Manchester, confirmed the sighting, suggesting it might be a meteor or “another object re-entering the Earth’s atmosphere”.
He saw “two bright lights, [which] seemed to bank over to the right then climb away at speed”.
David Moore, head of Astronomy Ireland, favours the meteor theory. He told The Times he was “1,000 per cent sure” the mysterious light was a fireball, or a flaming meteorite, tumbling through the atmosphere.
A flying saucer model created by US plastic artist Peter Coffin’s in 2009.
(Photo: Antonio Scorza/AFP/Getty)
One thing is certain: the truth is out there, and the Irish Aviation Authority intends to find it.
The organisation, which has launched an investigation into the 9 November sightings over Ireland’s south-west coast, has said it is unlikely that the incident involved alien life.
Yet these are simply the latest close encounters to fuel the imaginations of those who believe we are not alone.
The act of reporting a UFO sighting dates back to the 40s, with the first official account widely accepted to be that of a private pilot in 1947.
He reported seeing nine strange objects moving at speed across the state of Washington, comparing them to “saucers skipping on water”.
UFO hotline
There have been hundreds of alleged sightings – often involving unusual lights – since. Some are hoaxes, some can be explained by natural phenomena; others are seemingly genuine mysteries.
For years, people in the UK were able to report their sightings via a special Ministry of Defence (MoD) hotline.
The MoD eventually closed its dedicated UFO desk in November 2009, saying it served “no defence purpose” and was taking staff away from “more valuable defence-related activities”.
Declassified papers released by the National Archives in 2013 revealed the Ministry had logged 643 reported sightings in its final year, treble the previous year and the second-highest recorded since 1978, when there had been 750 alleged sightings.
The papers also contained reports from someone who had been “living with an alien” in Carlisle and sightings of UFOs over Stonehenge, Parliament and Blackpool Pier.
Further afield, cases such as the Roswell incident – the high-altitude weather balloon that crashed in New Mexico in 1947 and spawned a thousand conspiracy theories – show just how much interest the idea of UFOs can generate.
A store in Roswell, New Mexico, selling UFO souvenirs.
(Photo: Hector Mata/AFP/Getty)
Television shows such as The X-Files have indulged our fascination with all things extraterrestrial and, thanks in part to social media, people are still sharing their strange encounters.
Indeed, a video of what some believe to be a UFO was recorded in Northern Ireland just minutes before the recent sightings by the two pilots.
The dashcam footage, recorded by a member of the public as they drove to work in Coleraine, showed what they described as a “bright object” shooting across the sky.
In 2014, a pilot claimed he had experienced a close encounter while flying a passenger jet at 34,000ft over Berkshire the previous year.
According to reports, the captain was so convinced that the “silver, rugby ball”-shaped object would smash into his Airbus that he ducked as it headed towards the cockpit.
The UK Airprox Board, which investigates near-misses in British airspace, said that no other aircraft had been in the vicinity at the time. It also ruled out meteorological balloons. No military radars picked up any sign of a UFO, however.
How to report a sighting
For those who think they have seen something, the British UFO Research Association is among the organisations which will analyse sightings.
The voluntary organisation, which has been running for more than 50 years, receives between five and 20 reports a week – though only a few of these remain a mystery.
“Up to 98 per cent of sightings can be explained if they are reported very quickly and with accurate information,” says national investigations co-ordinator Heather Dixon.
“We have a form on our website for people to report sightings which asks the relevant questions.
“Eighty per cent of all sightings are now photographed, [but] that doesn’t mean anything on its own – we have to have supporting information."
Dixon explains that in cases where there are photos, the UFOs can normally be explained. A low-quality photo is often the problem in more difficult cases.
Heather Dixon, of the British UFO Research Association, said it is important to be objective about all potential sightings.
(Photo: David McNew/Newsmakers)
She says that UFO sightings highlight how differently people can perceive and interpret something in the sky.
“If you see something and you have no way to understand what that is, you use imagery that you have downloaded over your lifetime.
“The brain has to do something to identify or make some kind of explanation for what is happening.
“So if someone has a strong belief in the subject, and the idea that there are cover-ups, then they will relate that to their sighting.”
But, she adds: “That’s not to say there aren’t mysteries.
‘You have to be objective’
“On a personal level, I am very sceptical, but I have had a handful of things happen to me – not UFO-related – that have been stranger and have made me think.
“But you have to be objective. You have to investigate and research in a meticulous way. What I have learnt is the more you learn about anything, the less you realise you know.”
For Robert Massey, deputy executive director at the Royal Astronomical Society, a meteor is the most likely culprit behind the latest sighting.
“The idea that it is something entering the Earth’s atmosphere – a meteor – is the most likely case,” he says. “It is perhaps an unusually bright one and that, I imagine, is what they have seen.”
Dr Massey adds that the speed of the object lends credence to the object being a natural one – such as a meteor – as opposed to something like debris from a satellite.
“That would also explain why it won’t be on the radar,” he explains. “Meteors are pretty high up in the Earth’s atmosphere – well above the altitude you’d expect for a commercial flight.
“There’s no reason to jump to the conclusion that it is any kind of spaceship. It will almost certainly have a more mundane explanation.
“But the thing that’s nice to take from this is that there’s an awful lot of drama in the night sky. “It just reminds us that even the things for which we do have an explanation can be pretty spectacular.”
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Over mijzelf
Ik ben Pieter, en gebruik soms ook wel de schuilnaam Peter2011.
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