Wil je een videoclip bekijken en stoort het X-files-deuntje jou daarbij. Schakel het deuntje gewoon uit door in deze kolon, helemaal beneden op de 2 witte balkjes in het blauwe cirkeltje te klikken, tot een pijltje verschijnt. Veel kijk- en luisterplezier en bedankt voor jouw bezoek.
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.
UFO'S - MET HET LAATSTE NIEUWS OVER UFO'S BOVEN BELGIË EN IN ANDERE LANDEN...
UFO's in België en de rest van de wereld In België heb je vooral BUFON of het Belgisch UFO-Netwerk, dat zich met UFO's bezighoudt. BEZOEK DUS ZEKER VOOR ALLE OBJECTIEVE INFORMATIE ww.ufo.be.
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 maandeliiks tijdschrift uit, namelijk The MUFON UFO-Journal. Since 02/01/2013 is Pieter not only president (=voorzitter) of BUFON, but also National Director MUFON / Flanders and the Netherlands. We work together with the French MUFON Reseau MUFON/EUROP.
17-08-2017
A New Theory Suggests We May be the Only Technologically Advanced Civilization Still Around
A New Theory Suggests We May be the Only Technologically Advanced Civilization Still Around
Retired astrophysicist Daniel Whitmire re-examined the Fermi Paradox, and why the universe is silent if there is alien life out there. He believes that it's possible that humanity was the first to have become technologically advanced.
THE SOUND OF SILENCE
For retired astrophysicist Daniel Whitmire, currently a mathematics professor at the University of Arkansas (UARK), humanity is typical. Not exactly in the sense that we’re ordinary; we’re typical in a statistical sense, following a concept in modern cosmology called the principle of mediocrity. This principle suggests that in the absence of evidence to the contrary, we should consider humanity to be a typical member of a certain reference class.
This was Whitmire’s conclusion, in a study published in the International Journal of Astrobiology, when he revisited his thoughts on the Fermi Paradox — that we haven’t encountered alien life, despite the high probability of it existing — and again asked if there’s alien life out there. With all the billions of stars in billions of galaxies, chances are there’s bound to be other intelligent life in the cosmos. So, where are they?
“I used to tell my students that by statistics, we have to be the dumbest guys in the galaxy,” Whitmire said in a UARK press release. “After all, we have only been technological for about 100 years, while other civilizations could be more technologically advanced than us by millions or billions of years.”
But Whitmire changed his mind on this concept based on two observations: Firstly, that humanity was the first technologically advanced civilization that evolved on Earth, and we’re currently in our early technological development. (“Technological,” here, is to be understood as biological species that developed electronic devices and are capable of significantly changing the planet.)
On the surface, this may seem like an obvious observation. However, based on the Earth’s habitable time span — from around 50 billion years ago, and for an estimated billion years in the future — it would have been possible for other technological civilizations to precede us on this planet. The thing is, there’s no geologic record that shows someone else came before us. “We’d leave a heck of a fingerprint if we disappeared overnight,” Whitmire said.
ANYBODY OUT THERE?
But what about life outside of the Earth? Following the same principle of mediocrity, technological civilizations that lasts millions of years or longer are atypical, Whitmire says. If one considers a bell curve of all supposedly extant technological civilizations in the universe, humanity would fall in the middle 95 percent.
If that is the case, the lack of communication from similar civilizations around us does not bode well. Whitmire explains the silence of the cosmos as a product of how typical technological civilizations work: They usually go extinct after attaining technological knowledge. This is the same explanation held by other scientists, and one even suggests that we should look for traces of alien technology instead of alien life.
The “Great Filter” hypothesis is another possible explanation. It suggests that before any life in the universe becomes technological or before technological life goes beyond the bounds of its own planet, it had to overcome some extremely difficult evolutionary threshold. Some even think that climate change is humanity’s great filter.
For resident “Science Guy” Bill Nye, the Fermi Paradox should push humanity to explore further. The reason why we haven’t found intelligent extraterrestrial life or even simple alien life is because we haven’t been looking hard enough. There’s still a big chance that they’re somewhere out there.
Yet these theories assume that we’re not a typical representative of life in the cosmos. “If we’re not typical then my initial observation would be correct,” Whitmire said. “We would be the dumbest guys in the galaxy by the numbers.
Was the Wow! signal evidence of extraterrestrial intelligence? Forty years later, the debate continues: Edd Wheeler (Opinion)
Was the Wow! signal evidence of extraterrestrial intelligence? Forty years later, the debate continues: Edd Wheeler (Opinion)
A 1983 file photo of Ohio State University's "Big Ear" radio telescope where, 40 years ago this week, scientists searching for signs of intelligent life in outer space detected the still-debated Wow! signal. A recent assessment attributed the signal to hydrogen clouds from two comets but Edd Wheeler writes in the op-ed below that Jerry Ehman, the astronomer who famously named the moment with his "Wow!" notation on the printout, is not ruling anything out. (Plain Dealer Historical Photograph collection, File, 1983)
Edd Wheeler is a former federal administrative law judge with an interest in astrophysics. (Courtesy of Edd Wheeler)
TUCKER, Georgia -- The Search for Extraterrestrial Intelligence (SETI) was first conceived almost 60 years ago by the late Carl Sagan. In 1974 it took institutional form at the University of California, Berkeley. Today, its modern computers monitor 100 million frequency channels for potential signals from space.
However, lack of a credible finding of putative aliens has resulted in detractors calling SETI the Great Martian Chase.
SETI's most noted reception occurred 40 years ago this week, and was registered by three scientists, with shoestring budget and staff, using a primitive IBM computer having only 64,000 bytes of memory.
The "Big Ear" telescope at the Ohio State University Radio Observatory that operated from 1973 to 1997 was SETI's longest and most famous operation. Though small by later standards, it was then one of the world's foremost radio telescopes, a curved reflector 70 feet high and 420 feet long on its aluminum plane.
Just after 11 p.m. on Aug. 15, 1977, it recorded a type of transmission not encountered previously or since.
While Big Ear was monitoring the 1420-megahertz frequency, one reserved for scientific use in belief that potential extraterrestrial intelligence might broadcast on the frequency for neutral hydrogen, the most common element in the universe, signals were received from the direction of the constellation Sagittarius.
They were recorded at 12-second intervals of ten seconds for reception followed by two seconds of data processing by the computer. The transmission produced data that followed the observatory's antenna pattern more than 99 percent accurately.
Upon seeing the computer readout, astronomer Jerry Ehman simply penned "Wow!" on it, thus famously naming the transmission. He soon ruled out possible sources like ground emission, aircraft, satellites, and space debris.
Ehman believes the average signal strength was constant throughout the unprecedented length of 72 seconds and that the six intervals were only timed recordings caused by the design of equipment and antenna pattern.
There was little doubt by all on-scene scientists that they had accurately recorded an artificial transmission, one caused by something other than natural phenomena such as pulsars.
Ehman initially was cautious about conclusions on the source. But in his 20th anniversary report on the "Wow!" signal, he wrote that "Big Ear" data were reliable and, lacking evidence to the contrary, that the source was probably extraterrestrial intelligence. Although he now thinks the matter an "open question," he continues as before to believe that the signal is "a tantalizing candidate" as ETI, which he reiterates as "certainly a possibility."
Fellow scientist Robert Dixon confidently stated that the source was from "beyond the moon." He wrote in 1985 that, for SETI's first decade and among its 30,000 "detections," the Wow! signal was clearly "most prominent."
The late Dr. John Kraus, as quoted in a 2012 book on the topic by Robert H. Gray, ventured that it might have been an ETI "signal" but that this was speculative.
In 2016, scientists at the Center of Planetary Science, a small group near Tampa promoting astronomy, suggested the Wow! signal likely was not an artificial transmission but a natural phenomenon caused by radiation from massive hydrogen clouds surrounding two remote comets discovered in 2006 and 2008.
As evidence, they presented a recorded radio signal emitted by a comet at 1420.25 megahertz, very close to the frequency of natural hydrogen monitored for many years by "Big Ear."
It is uncertain whether this finding solidly refutes the Wow! transmission as a possible ETI signal.
An inherent problem is that humans may not be "wired" to recognize a real interstellar "signal."
Britain's Astronomer Royal Martin Rees is chairman of the Breakthrough Initiatives, a ten-year, $100 million search for extraterrestrial intelligence, intended to answer Stephen Hawking's query, "if we are alone in the dark."
Rees emphasizes that putative aliens likely possess intelligence fundamentally different from ours, and thus "may package reality" and convey it in ways not understandable. He seeks a "manifestly artificial" signal.
However, if certainty is the gauge, how can signal receipt be manifestly established if the source has different intelligence and expression than ours?
The Wow! signal was not manifestly from ETI, yet it seemed credibly outside the solar system. Some question whether intelligence, as we know it, exists beyond Earth.
At the 40th anniversary of the Wow! signal, it is time to acknowledge that, in a galaxy of 400 billion stars and a universe of more than 500 billion galaxies, we may not comprehend the possible qualities of intelligence in other worlds, but by probability it is incomprehensible that extraterrestrial intelligence does not exist.
The Breakthrough Initiatives will formulate a compact yet substantive interstellar signal about humans, our values and achievements.
An equal concern has gone unmentioned. What if Earth was identified as a living world long before man's appearance, and what should be our concern if distant observers have intelligently and correctly concluded that we have produced the likes of Michelangelo, Shakespeare, Bach, and Newton, along with Tamerlane, Stalin, and Hitler, and with an identifiable practice of superpredation? What then might a potential signal from afar look like?
Wow! indeed.
Edd Wheeler, a graduate of the U.S. Air Force Academy and a veteran of the Vietnam War, is a former federal administrative law judge whose articles on the Wow! signal and Breakthrough Initiatives have appeared in the "Journal of the British Interplanetary Society."
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The pulsar maps on the Voyager probes pinpoint our location in the galaxy—even as some experts debate the pros and cons of signalling ET.
Forty years ago, we sent a map to Earth sailing deep into the cosmos. Copies of this map are etched into each of the twin Voyager spacecraft, which launched in the late 1970s and are now the farthest spacecraft from home. One of the probes has already slipped into interstellar space, and the other is skirting the fringes of our sun’s immediate neighbourhood. If it’s ever intercepted and decoded by extraterrestrials, the map will not only reveal where to find our watery little world, but also when the space probe that delivered it to alien hands left home. “We needed to put something on the Voyager that said where it came from, and how long it was travelling,” says my dad, Frank Drake, who designed the map. The Voyager version of route-finding pins the sun onto our galaxy using 14 pulsars, which are the rapidly spinning corpses of exploded stars. It’s a cipher unlike anything made before, the kind of object that drives entire fictional quests—and that is currently spurring arguments over the intelligence of broadcasting our existence to civilisations with possibly nefarious proclivities. “Back when Drake did the pulsar map, and Carl Sagan and the whole team did the Voyager record, there hadn't been very much debate over the pros and cons of contact with extraterrestrial intelligence,” says York University’s Kathryn Denning, an anthropologist who studies the ethics of sending messages to extraterrestrials. “Now, however, as you know, there is a major debate among scientists and a variety of stakeholders about the wisdom of doing anything other than listening.”
STELLAR MAP MAKING Drake’s cosmic directions to Earth are stamped onto the cover of the Voyager Golden Record, two of which have been ferrying the sights and sounds of planet Earth across the interstellar sea since 1977. But unlike the record, which grew into its final form during one short summer, the map took shape years earlier, in late 1969. Back then, my dad and Carl Sagan were designing a message to put on the Pioneer 10 and 11 spacecraft, which would be flung from the solar system after an encounter with Jupiter. One of the components he and Sagan wanted to include was a map that pointed to Earth in both space and time. The question was, how do you create such a map in units that an extraterrestrial might understand? Earth-years would be perfectly meaningless, because they are derived from our planet’s particular path around the sun. And there’s also the question of coordinates--in space, no one can find you using up, down, east, or west. Even the stars themselves are constantly shifting on astronomical time scales. “Second star to the right and straight on ‘til morning” doesn’t quite work if the map is found a billion years from now and the star in question—say, Betelgeuse—has long since exploded and died.
THE MAGIC ABOUT PULSARS To my dad, the answer was obvious: pulsars. Discovered in 1967 by Jocelyn Bell Burnell, these dense husks of expired stars were perfect blazes in both space and time. For starters, pulsars are incredibly long-lived, staying active for tens of millions to multiple billions of years. Also, each pulsar is unique. Many spin faster than anything on Earth, sometimes thousands of times each second, and they emit pulses of electromagnetic radiation like lighthouses. By timing those pulses, astronomers can determine a pulsar’s spin rate to a ridiculous degree of accuracy, and no two are alike. But pulsars do slow down, sometimes by a mere but measurable billionths of a second a year. By calculating the difference between a pulsar’s spin rate when the map is found versus the spin period inscribed on the map, an intelligent being could figure out how long it had been since the map was made. “There was a magic about pulsars … no other things in the sky had such labels on them,” Drake says. “Each one had its own distinct pulsing frequency, so it could be identified by anybody, including other creatures after a long period of time and far, far away.”
Voyager 2 launched on August 20, 1977, as seen here in a picture taken at Cape Canaveral in Florida. About two weeks later, NASA launched Voyager 1.
PHOTOGRAPH BY NASA, JPL-CALTECH
He reasoned that if those beings had figured out what pulsars were, they surely knew where the whirling, dead stars resided in the galaxy. Using the map, they could then follow the trail back to the sun. After a roughly three-minute discussion with Sagan, the decision was made. Drake drew the map using 14 known pulsars (today, that original pencil-drawn pulsar map is casually tucked into an old produce box at home). The length of the lines connecting each pulsar to a central point—the sun—indicates how far they are from home. Along those distance markers, he inscribed the pulsars’ spin rates out to 12 digits in binary code, so any curious aliens would know which pulsars he’d chosen as anchors. Successfully decoding the map would unambiguously pinpoint the sun’s position and the timeframe of the spacecraft’s launch. Today, that makes some scientists and philosophers very nervous.
DANGEROUS BEACON? When the Voyager spacecraft launched, astronomers had no evidence that other planets even existed outside our solar system, much less worlds capable of hosting alien life. Now, thanks to missions like NASA’s planet-hunting Kepler endeavor, we know that planets are common in the galaxy, and that a sizable percentage of those worlds could be like Earth. The revelation has spawned efforts to send directed radio messages toward promising stars sytems. In the wake of these discoveries, a debate has emerged over the ethics of intentionally announcing our presence to the stars. Some think the endeavour is foolish and dangerous, given how little we know about what might be out there. Others would rather prioritise listening to the stars over talking to them. For the Voyager spacecraft, the truth is already out there, as the maps they carry hurtle deeper into the void.
An illustration of one of the Voyager probes traveling in space.
PHOTOGRAPH BY NASA
“In those days, all the people I dealt with were optimists, and they thought the ETs would be friendly,” Drake says. “Nobody thought, even for a few seconds, about whether this might be a dangerous thing to do.” So what are the chances of the map actually reaching extraterrestrial shores aboard the Voyagers? “Very small,” Drake says. “The thing is going something like 10 kilometres per second, at which speed it takes—for the typical separation of stars—about half a million years to go from one star to another. And of course, it’s not aimed at any star, it’s just going where it’s going.” If an extraterrestrial civilisation has sufficiently powerful radars, it might be able to detect the Voyager spacecraft from afar. But that’s still unlikely, Drake says, which means the Voyagers’ sights, sounds, and maps to planet Earth may forever sail silently through the cosmos. The reality is that humans have been passively announcing our presence to the cosmos for nearly a century via radar, radio, and TV transmissions. And with the rise of private space enterprises, who knows what new message to the stars might end up making its way into space? Denning urges everyone to act thoughtfully and consider the pros and cons of intentionally hailing aliens. “We're all on this Earth together,” she says.
STORY PRODUCED IN PARTNERSHIP WITH HHMI TANGLED BANK STUDIOS. Header: The cover of the Voyager Golden Record. The starburst pattern seen in the upper right is the pulsar map to Earth. PHOTOGRAPH BY NASA
Advanced alien civilizations could find our planet with the aid of Cosmic Maps NASA launched into space some 40 years ago. However, Dr. Frank Drake, the man who helped design the charts has suggested these maps could be dangerous for our species.
This is the diagram carried aboard Pioneer 10 and Pioneer 11.
Image Credit: NASA.
Our quest for alien life goes back more than you’d imagine. But perhaps the most important step towards finding our cosmic neighbors began in the 1970’s when NASA sent maps revealing our planet’s location into space, onboard of four spacecraft in hopes that one day we would be able to communicate if anyone else is out there.
However, despite the fact that sending the maps of Earth into space was a great step for mankind, the creator of the maps—Dr. Frank Drake—has spoken out about the potentially ‘dangerous’ decisions to send the maps into space over 40 years ago.
All f the four spacecraft carrying the maps—Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2—have left our solar system and are heading towards deep space with our planet’s coordinates embedded onto their body.
Dr. Drake who worked at NASA to design the ‘cosmic’ charts placed on board Pioneer 10 and Pioneer 11 launched in 1972 and 1973 respectively believes not everything is positive about sending the maps.
The Voyager spacecraft were launched into space with golden records (pictured) on board.
Image Credit: NASA
In an interview with his daughter Nadia Drake, a reporter from National Geographic, Dr. Drake said: “In those days, all the people I worked with were optimists, and they believed how ETs would be friendly, Nobody thought, even for a few seconds, about whether this might be a dangerous thing to do.”
The plaques placed on board the Pioneer spacecraft are a message from our civilization. They depict a man and a woman standing side by side, next to a map of Earth, which plots its position in relation to distant pulsar stars.
Why pulsar stars? Because these stars are long-lasting stars and are so bright that they could help guide aliens in the right direction towards Earth.
The maps on board the Voyager spacecraft are of similar design. The Voyager 1 and 2 feature a golden record on board, with similar pulsar stars to our planet.
NASA wanted to put something on board the spacecraft saying where we come from, who we are, and how long our spacecraft were traveling.
Furthermore, the records also contain various sounds from nature, and noises produced by humans like a train, and a kiss between a mother and a child.
However, despite all potential danger these cosmic charts pose in outer space, Dr. Drake says that the chance of Aliens intercepting the messages and finding out wehre we are are “very small”
“The thing is going something like 10 kilometers [6.2 miles] per second, at which speed it takes – for the typical separation of stars – about half a million years to go from one star to another,” added Dr. Drake.
Apparently, things about E.T. and visitations to Earth changed since the 1970’s. Now it seems more people are inclined to avoiding aliens at any cost.
Now, more experts are leaning towards the idea that we should not reveal ourselves to aliens.
Professor Stephe Hawking said in an interview that if aliens found us, it would be something comparable to when the Native Americans first encountered Christopher Columbus—something that did not turn out so well for the natives.
Stephen Hawking has said that if aliens ever discovered Earth, they would probably want to conquer and colonize it.
Earlier this year, both the scientific community and “alien enthusiasts” were excited when NASAannounced in Februaryit had found a star system 40 light-years away with seven Earth-size rocky planets. Called Trappist-1, the system is thought to have at least three of those planets in a potentially habitable zone with the possibility of liquid surface water.
But being located at the right distance from the parent star is not nearly enough for a planet to be actually habitable because life as we know it doesn’t seem to spring up so easily. Among the many and varied factors, take, for example, the matter of the star’s age. Trappist-1 is thought to be anywhere between 5.4 billion years and 9.8 billion years old, which is at least 20 percent (and up to over 100 percent) older than our own solar system that formed about 4.5 billion years ago.
In a statement Friday, NASA explained: “If we want to know more about whether life could survive on a planet outside our solar system, it’s important to know the age of its star. Young stars have frequent releases of high-energy radiation called flares that can zap their planets’ surfaces. If the planets are newly formed, their orbits may also be unstable. On the other hand, planets orbiting older stars have survived the spate of youthful flares, but have also been exposed to the ravages of stellar radiation for a longer period of time.”
This artist's concept shows what the Trappist-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star. The planets have been designated letters b to h, from closest to farthest.
Photo: NASA/JPL-Caltech
To estimate the age of Trappist-1, Adam Burgasser, an astronomer at the University of California, San Diego, and Eric Mamajek, deputy program scientist for NASA’s Exoplanet Exploration Program based at NASA’s Jet Propulsion Laboratory, Pasadena, California, used a number of indirect clues. These included the speed of the star as it moves in its orbit within the Milky Way (older is usually faster), the chemical composition of its atmosphere and the number of flares seen during observation periods.
The old age estimation they arrived at is not very unusual for the kind of star Trappist-1 is — an ultra-cool dwarf. It has a mass of less than a tenth of the sun, and its planets are all very close orbits to it. Despite the relatively cool temperature, radiation from the star cloud has, over billions of years, evaporated any atmosphere and water that may have existed on any of the three planets in the habitable zone — much the same way as Mars.
All the planets of Trappist-1 are thought to be rocky but with densities lower than Earth, it is also possible that volatile molecules (like water and carbon dioxide) create a thick atmosphere, thereby shielding the planets from most of the harmful radiation. The planets are also thought to be tidally locked to the star (the same side always faces the star, like the moon and Earth), so an atmosphere would also mean that some of the incoming heat would be distributed to the planets’ night side too. But a very thick atmosphere also creates the possibility of an excessive greenhouse effect, which would overheat the planet, like on Venus.
“If there is life on these planets, I would speculate that it has to be hardy life because it has to be able to survive some potentially dire scenarios for billions of years,” Burgasser, first author of a new research paper on the topic, said in the statement. “Our results really help constrain the evolution of the TRAPPIST-1 system, because the system has to have persisted for billions of years. This means the planets had to evolve together, otherwise the system would have fallen apart long ago,” he added.
This provides more evidence of the system’s stability, which was first initially thought to be very unstable and the planets doomed to crash into each other in less than one million years. Previously, a study published in May by scientists and musicians from the University of Toronto said the planets had very stable orbits that formed ratios of whole numbers.
This illustration shows what the Trappist-1 system might look like from a vantage point near planet Trappist-1f (at right).
Photo: NASA/JPL-Caltech
The temperature and brightness of stars the mass of Trappist-1 tend to remain more or less constant over very long periods of time, even in terms of cosmic time-scales. With the exception of occasional magnetic flaring events, the lifetime of Trappist-1 is estimated to be over 10 trillion years (the universe is only 13.7 billion years, by comparison.
“Stars much more massive than the sun consume their fuel quickly, brightening over millions of years and exploding as supernovae. But Trappist-1 is like a slow-burning candle that will shine for about 900 times longer than the current age of the universe,” Mamajek said in the statement.
Trappist-1 is so-named because the main instrument that led to its discovery is Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. NASA’s Spitzer Space Telescope and other ground-based telescopes were also used in the discovery of the star system.
The paper by Burgasser and Mamajek, titled “On the Age of the Trappist-1 System,” has been accepted for publication in the Astrophysical Journal and is available online on the preprint server arXiv.
Associate Professor of Astronomy and Astrophysics, Pennsylvania State University
Disclosure statement
Jason Wright acknowledges funding from NASA, the NSF, the Center for Exoplanets and Habitable Words at The Pennsylvania State University, and from Breakthrough Listen, part of the Breakthrough Initiatives sponsored by the Breakthrough Prize Foundation (https://breakthroughinitiatives.org/).
The Conversation UK receives funding from Hefce, Hefcw, SAGE, SFC, RCUK, The Nuffield Foundation, The Ogden Trust, The Royal Society, The Wellcome Trust, Esmée Fairbairn Foundation and The Alliance for Useful Evidence, as well as sixty five university members.
Forty years ago, NASA launched Voyager I and II to explore the outer solar system. The twin spacecraft both visited Jupiter and Saturn; from there Voyager I explored the hazy moon Titan, while Voyager II became the first (and, to date, only) probe to explore Uranus and Neptune. Since they move too quickly and have too little propellant to stop themselves, both spacecraft are now on what NASA calls their Interstellar Mission, exploring the space between the stars as they head out into the galaxy.
Both craft carry Golden Records: 12-inch phonographic gold-plated copper records, along with needles and cartridges, all designed to last indefinitely in interstellar space. Inscribed on the records’ covers are instructions for their use and a sort of “map” designed to describe the Earth’s location in the galaxy in a way that extraterrestrials might understand.
Since we still have not detected any alien life, we cannot know to what degree the records would be properly interpreted. Researchers still debate what forms such messages should take. For instance, should they include a star map identifying Earth? Should we focus on ourselves, or all life on Earth? Should we present ourselves as we are, or as comics artist Jack Kirby would have had it, as “the exuberant, self-confident super visions with which we’ve clothed ourselves since time immemorial”?
But the records serve a broader purpose than spreading the word that we’re here on our blue marble. After all, given the vast distances between the stars, it’s not realistic to expect an answer to these messages within many human lifetimes. So why send them and does their content even matter? Referring to earlier, similar efforts with the Pioneer spacecraft, Carl Sagan wrote, “the greater significance of the Pioneer 10 plaque is not as a message to out there; it is as a message to back here.” The real audience of these kinds of messages is not ET, but humanity.
The choice to include music has inspired introspection on the nature of music as a human endeavor, and what it would (or even could) mean to an alien species. If an ET even has ears, it’s still far from clear whether it would or could appreciate rhythm, tones, vocal inflection, verbal language or even art of any kind. As music scholars Nelson and Polansky put it, “By imagining an Other listening, we reflect back upon ourselves, and open our selves and cultures to new musics and understandings, other possibilities, different worlds.”
Engineers mount the Golden Record and secure its cover on Voyager 1.NASA/JPL-Caltech, CC BY
The records also represent humanity’s deliberate effort to put artifacts among the stars. Unlike everything on Earth, which is subject to erosion and all but inevitable destruction (from the sun’s eventual demise, if nothing else), the Golden Records are essentially eternal, a permanent time capsule of humanity. And unlike the Voyager spacecraft themselves – which were designed to have finite lifespans and whose journey into interstellar space was incidental to their primary function of exploring the outer planets – the Golden Records’ only purpose is to serve as ambassadors of humanity to the stars.
Placing artifacts in interstellar space thus makes the galaxy subject to the social studies, in addition to astronomy. The Golden Records mark our claim to interstellar space as part of our cultural landscape and heritage, and once the Voyager spacecraft themselves are not functional any longer, they will become proper achaeological objects. They are, in a sense, how we as a species have planted our flag of exploration in space. Anthropologist Michael Oman-Reagan muses, “Has NASA been to interstellar space because this spacecraft has? Have we, as a human species, [now] been to interstellar space?”
I would argue we have, and we are a better species for it. Like the Pioneer plaques and the Arecibo Message before them, the Golden Records inspire us to broaden our minds about what it means to be human; what we value as humans; and about our place and role in the cosmos by having us imagine what we might, or might not, have in common with any alien species our Voyagers eventually encounter on their very long journeys.
Never mind the bizarre theories that have put aliens on the moon constructing creepy obelisks and even inside to pilot it like a spaceship—new revelations about its vanished magnetic field may shed light on how other moons could potentially host alien life forms.
While the moon now has nothing but a ghost of what was once a magnetic field, a new study has found that its magnetic field must have lasted a billion years longer than what scientists previously estimated. This extended shelf life could mean that magnetic fields on distant celestial bodies may be able to survive long enough to support some sort of extraterrestrial life.
Whether anything ever crawled around on the moon itself is a mystery, but science has been able to find out approximately how strong its dead magnetic field used to be by using moon rocks brought back to Earth by Apollo astronauts. The rocks are relics of a period between 3.56 and 4.25 billion years ago, when the moon’s magnetic field could have been anywhere from 20 to 110 microtesla (in comparison to Earth’s 50). Sometime around 3.19 billion years ago, the strength of the lunar magnetic field plunged to under 4 microteslas, and the question of what happened after that and before it dissipated completely remains unanswered.
Apollo 15 sample 15498.
Greater insight into what the magnetic field of the moon was like when it actually existed could tell us more about how those of alien moons and planets influence their potential for habitability. Earth’s magnetic field shields our planet from getting radiation-bombed by the sun, as Mars did when its own was ruthlessly stripped away by stellar winds to turn it from a planet that is thought to have once been running with rivers into a dry, dusty wasteland.
"Magnetic fields can shield planets from stellar winds which can strip atmospheres of water, which is important for planetary habitability," said lunar geophysicist Sonia Tikoo, who led a study recently published in Science Advances.
An Apollo 15 moon rock, sample 15498, was tested by Tikkoo and her colleagues for what it could reveal about the past. Moon rocks have preserved evidence of the existence and strength of the moon’s ancient magnetic field through thousands of metallic micrograins that aligned with its force as they cooled from a molten state. 15498 is one of the rare ones that formed after volcanism on the moon, and with it, igneous rock formation sputtered to death 3 billion years ago. This one was found to have formed from an intense cosmic impact around 1 to 2.5 billion years ago.
Sample 15498’s magnetic properties were first gauged by a supersensitive magnetometer before it was exposed to an artificial magnetic field in the lab. The rock was then heated to be as close as possible to the extreme temperatures it emerged from, about 1,436 degrees Fahrenheit. How magnetized the rock gets is compared to the natural magnetic field previously measured to determine what the strength of the lunar magnetic field was when it formed. The rock revealed that there was still the vestige of a magnetic field with a strength of 5 microteslas from 1 to 2.5 billion years ago.
The reason the magnetic field held on for so long is thought to be a dynamo much like Earth’s liquid metal core (which fuels our own magnetic field). There are several theories as to how the lunar dynamo could have lasted for billions of years, but it is still an unsolved mystery.
What was once a liquid metallic core (that glowing red thing that looks like the Eye of Sauron) is thought to be what made the lunar magnetic field last a billion years longer than previously thought.
So what does all this say about aliens?
“Even small planetary bodies can generate long-lived magnetic fields operating on billion-year timescales, so it is possible that small exoplanets or exomoons might be able to preserve water on timescales long enough to permit life to develop,” said Tikoo.
Don’t be surprised if the first sign of extraterrestrial life emerges from an exomoon.
The south pole of Jupiter is seen from an altitude of 32,000 miles (52,000 kilometers) in this enhanced color mosaic of images from NASA's JunoCam. Cyclones up to 600 miles wide (1,000 km) are visible.
Credit: NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles SCOTT BOLTON - 3
Juno gets a first look at Jupiter's marvelous poles, the world's largest (current) aircraft goes for a spin, Earth science loses on the proposed NASA budget and two astronauts perform an urgent spacewalk — it's Space.com's top news stories of the week.
Jupiter whirls
The first science results from NASA's Juno probe reveal huge cyclones raging near Jupiter's north and south poles and the workings of is spectacular auroras. Juno is the first spacecraft to get a close look the planet's beautiful and bizarre poles. [Full Story: Mysteries at Jupiter: NASA's Juno Probe Reveals Cyclones, Auroras & Surprises]
Astronauts kept freeze-dried mouse sperm on the International Space Station for nine months — and when brought back to Earth it gave rise to healthy pups. [Full Story: Freeze-Dried Space Sperm Gives Rise to Healthy Baby Mice]
After a computer relay box malfunctioned, NASA astronauts Peggy Whitson and Jack Fischer went out for a quickly-planned spacewalk to replace the failedpart. (Don't worry, a backup took over in the meantime.) Whitson built the replacement from spare parts aboard the International Space Station. [Full Story: Astronauts Restore Space Station to Full Health in Quick Repair Spacewalk]
Clash of the dwarfs
New research suggests that most of the Milky Way's antimatter could come from the collision of two special kinds of white dwarfs — the Earth-size cores of dead stars. [Full Story: Supernova Face-Off May Solve 40-Year-Old Antimatter Mystery]
Mammoth flier success
A massive blimp-like aircraft called the Airlander 10 successfully flew for 180 minutes and landed, testing its improved landing technology and handling. It's the third test flight for the world's largest aircraft currently flying, which isdesigned to stay in the air for up to 5 days at a time with people on board. [World's Largest Aircraft Completes Successful Test Flight]
Earth science nix
The White House's official 2018 budget request curtails five NASA Earth-science missions, including the Plankton, Aerosol, Cloud ocean Ecosystem satellite; the Orbiting Carbon Observatory-3 experiment; the Climate Absolute Radiance and Refractivity Observatory Pathfinder; the Earth-viewing instruments aboard the Deep Space Climate Observatory spacecraft and, now, the Radiation Budget Experiment. [Full Story: Trump's 2018 Budget Request Axes 5 NASA Earth-Science Missions]
The Cassini spacecraft has seen Saturn through the seasons as the planet has orbited the sun, watching its dramatic changes. Now, it's finally the planet's solstice and the end of the spacecraft's second extended mission — just in time for its Sept. 15 Grand Finale dive into the planet's atmosphere. [Full Story: Saturn Solstice: Cassini Gets 'Ringside Seat' to Dramatic Seasonal Changes]
Listening in
The world's most sensitive dark matter detector, XENON1T, has gone online deep beneath a mountain in Italy, completing a 30-day science run hunting for the minuscule fireworks that could be caused by a certain type of dark matter ramming into a xenon atom inside the detector. [Full Story: The World's Most Sensitive Dark Matter Detector Is Now Up and Running]
It's a Phantom
The Defense Advanced Research Projects Agency (DARPA) has selected Boeing to build the U.S. military's new XS-1 space plane. The plane, called the Phantom Express, is designed to launch to the edge of space to deploy a second stage rocket, which would deposit a satellite in orbit. [Full Story: US Military's XS-1 Space Plane Will Be Built by Boeing (Video)]
TRAPPIST-1 would like to remind you that it was drinkin’ beer while you were still rompin’ around in your nappies — or whatever old people say. The ultra cool dwarf star system, which first was announced back in February, has garnered a lot of interest because it harbours seven Earth-size planets. At least three of those planets are within the habitable zone that can support liquid water and potentially, life. As we’re all clamouring to get off this planet understand this alien system, a duo of researchers has figured out some pretty salient information about its star’s age.
The team of astronomers used information gathered from various telescopes to determine TRAPPIST-1's age, which they estimate is between 5.4 and 9.8 billion years old. Our Sun is a whippersnapper by comparison: it’s only about 4.5 billion years old.
“We don’t get the birth certificates of stars when we find them, we just see how they are today,” University of California, San Diego astronomer Adam Burgasser, a co-author on the research, which is set to be published on The Astrophysical Journal, told Gizmodo. “So we had to look for clues that might change on the star over time.”
Artist’s rendering of the TRAPPIST-1 planetary system.
(Image: NASA/JPL-Caltech)
Burgasser and his colleague, NASA Exoplanet Exploration Program deputy program scientist Eric Mamajek, used various lines of known data about TRAPPIST-1 to piece together a statistical constraint, which is basically a damn good educated guess about the star’s age. For clues, the team looked at factors like the speed of TRAPPIST-1's orbit around the Milky Way, its atmosphere’s composition, and more.
Understanding more about this foreign star system just for the sake of it is pretty cool — after all, TRAPPIST-1 is so delightfully weird. But understanding the system’s age could have some pretty big implications for life on the planets, if there is any.
“Understanding age is pretty important important when you think about the development of planets themselves, and potentially life on these planets,” Burgasser said. “It took about four billion years for complex life to form on Earth, so if we’re thinking about if there’s any life on these planets, how long has it been there to evolve and develop.”
Obviously, the question of whether or not the TRAPPIST-1 planets can support life is up for debate. Some astronomers think that life probably couldn’t sustain itself on these planets, due to their close proximity to their host star. M dwarf stars like TRAPPIST-1 are known for spitting off large solar flares, and some researchers think this could have eroded the planets’ atmospheres. Also, after being so close to their star for billions of years, it’s possible that any water on these planets has boiled away, due to eons of bombardment with high-energy radiation. Of course, other researchers think there’s a shot life on these planets could exist in certain places, so at this point we’re still left with more questions than answers.
Hopefully, the launch of big telescopes like James Webb will aid in our understanding of alien systems like TRAPPIST-1. Now that we know it’s old, it seems there are even more mysteries out there waiting to be solved.
For as long as we have kept records, humanity has marveled at the night sky. We have looked at the heavens to determine the will of the gods and to wonder about the meaning of it all. The mere 5,000 stars we can see with the unaided eye have been humanity’s companions for millennia.
Modern astronomical facilities have shown us that the universe doesn't consist of just thousands of stars — it consists of hundreds of billions of stars in our galaxy alone, with trillions of galaxies. Observatories have taught us about the birth and evolution of the universe. And, on Aug. 3, a new facility made its first substantive announcement and added to our understanding of the cosmos. It allows us to see the unseeable, and it showed that the distribution of matter in the universe differed a bit from expectations.
The Dark Energy Survey (DES) is a collaboration of about 400 scientists who have embarked on a five-year mission to study distant galaxies to answer questions about the history of the universe. It uses the Dark Energy Camera (DEC) attached to the Victor M. Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatoryin the Chilean Andes. DEC was assembled in the U.S. at Fermilab near Batavia, Illinois, and is a 570-megapixel camera able to image galaxies so far away that their light is a millionth as bright as the dimmest visible stars.
Dark energy and dark matter
DES is hunting for dark energy, which is a proposed energy field in the universe that is a repulsive form of gravity. While gravity exerts an irresistible attraction, dark energy pushes the universe to expand at an ever-increasing rate. Its effect was first observed in 1998, and we still have many questions about its nature.
However, by measuring the location and distance of 300 million galaxies in the southern night sky, the survey will be able to make important statements about another astronomical mystery, called dark matter. Dark matter is thought to be five times more prevalent in the universe than ordinary matter. Yet it doesn’t interact with light, radio waves or any form of electromagnetic energy. And it doesn’t appear to congregate to form large bodies like planets and stars.
Map of dark matter made from gravitational lensing measurements of 26 million galaxies in the Dark Energy Survey.
Credit: Chihway Chang of the Kavli Institute for Cosmological Physics at the University of Chicago and the DES collaboration
There is no way to directly see dark matter (hence the name). However, its effects can be seen indirectly by analyzing how fast galaxies rotate. If you calculate the rotational speeds supported by the galaxies’ visible mass, you will discover that they rotate more quickly than they should. By all rights, these galaxies should be torn apart. After decades of research, astronomers have concluded that each galaxy contains dark matter, which generates the additional gravity that holds the galaxies together. [6 Weird Facts About Gravity]
Dark matter in the universe
However, on the much larger scale of the universe, studying individual galaxies is not sufficient. Another approach is needed. For that, astronomers must employ a technique called gravitational lensing.
Gravitational lensing was predicted in 1916 by Albert Einstein and was first observed by Sir Arthur Eddington in 1919. Einstein’s theory of general relativity says that the gravity that we experience is really caused by the curvature of space-time. Since light travels in a straight line through space, if space-time is curved, it will look to an observer as if light were travelling a curved path through space. [8 Ways You Can See Einstein's Theory of Relativity in Real Life]
This phenomenon can be harnessed to study the amount and distribution of dark matter in the universe. Scientists who peer at a distant galaxy (called the lensing galaxy), which has another galaxy even farther away behind it (called the observed galaxy), can see a distorted image of the observed galaxy. The distortion is related to the mass of the lensing galaxy. Because the mass of the lensing galaxy is a combination of visible matter and dark matter, gravitational lensing allows scientists to directly observe the existence and distribution of dark matter on scales as large as the universe itself. This technique also works when a large cluster of foreground galaxies distorts the images of clusters of even more distant galaxies, which is the technique employed for this measurement.
Lumpy or not?
The DES collaboration recently released an analysis using exactly this technique. The team looked at a sample of 26 million galaxies at four different distances from Earth. The closer galaxies lensed ones that were farther away. By using this technique and looking carefully at the distortion of the images of all of the galaxies, they were able to map out the distribution of invisible dark matter and how it moved and clumped over the past 7 billion years, or half the lifespan of the universe.
As expected, they found that the dark matter of the universe was "lumpy." However, there was a surprise — it was a little less lumpy than previous measurements had predicted.
One of these contradictory measurements comes from the remnant radio signal from the earliest time after the Big Bang, called the cosmic microwave background (CMB). The CMB contains within it the distribution of energy in the cosmos when it was 380,000 years old. In 1998, the Cosmic Background Explorer (COBE) collaboration announced that the CMB was not perfectly uniform, but rather had hot and cold spots that differed from uniform by 1 part in 100,000. The Wilkinson Microwave Anisotropy Probe (WMAP) and Planck satellites confirmed and refined the COBE measurements.
Over the 7 billion years between when the CMB was emitted and the time period studied by DES, those hotter regions of the universe seeded the formation of structure of the cosmos. Nonuniform energy distribution captured in the CMB, combined with the amplifying force of gravity, caused some spots in the universe to become denser and others less so. The result is the universe we see around us.
The CMB predicts the distribution of dark matter for a simple reason: The distribution of matter in our universe in the present depends on its distribution in the past. After all, if there were a clump of matter in the past, that matter would attract nearby matter and the clump would grow. Similarly, if we were to project into the distant future, the distribution of matter today would affect tomorrow's for the same reason.
So, scientists have used measurements of the CMB at 380,000 years after the Big Bang to calculate what the universe should look like 7 billion years later. When they compared the predictions to the measurements from DES, they found that the DES measurements were a little less lumpy than the predictions.
Incomplete picture
Is that a big deal? Maybe. The uncertainty, or error, in the two measurements is big enough that it means they don’t disagree in a statistically significant way. What that simply means is that no one can be sure that the two measurements really disagree. It could be that the discrepancies arise by chance from statistical fluctuations in the data or small instrumental effects that were not considered.
Even the study’s authors would suggest caution here. The DES measurements have not yet been peer-reviewed. The papers were submitted for publication and the results were presented at conferences, but firm conclusions should wait until the referee reports come in.
So, what is the future? DES has a five-year mission, of which four years of data have been recorded. The recently announced result uses only the first year’s worth of data. More recent data is still being analyzed. Further, the full data set will cover 5,000 square degrees of the sky, while the recent result only covers 1,500 square degrees and peers only half of the way back in time. Thus, the story is clearly not complete. An analysis of the full data set won’t be expected until perhaps 2020.
Yet, the data taken today already could mean that there is a possible tension in our understanding of the evolution of the universe. And, even if that tension disappears as more data is analyzed, the DES collaboration is continuing to make other measurements. Remember that the letters "DE" in the name stand for dark energy. This group will eventually be able to tell us something about the behavior of dark energy in the past and what we can expect to see in the future. This recent measurement is just the very beginning of what is expected to be a scientifically fascinating time.
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.
This version of the article was originally published on Live Science.
'Het leven is mogelijk meerdere keren op aarde ontstaan'
'Het leven is mogelijk meerdere keren op aarde ontstaan'
Caroline Kraaijvanger
Voordat onze voorouders ontstonden, leefden er wellicht andere complexe levensvormen op aarde die het uiteindelijk niet gered hebben.
Aangenomen wordt dat het ontstaan van complexe levensvormen op aarde heel bijzonder was en in de lange geschiedenis van onze planeet maar één keer plaatsvond. En wel nadat de hoeveelheid zuurstof in de atmosfeer rap was toegenomen. Maar nieuw onderzoek trekt die aanname nu ernstig in twijfel. De studie toont namelijk aan dat de hoeveelheid zuurstof in de atmosfeer niet één keer, maar zeker twee keer rap toe nam.
Kleine kans “Er is fossiel bewijs voor complexe levensvormen die tot zo’n 1,75 miljard jaar geleden leefden,” legt onderzoeker Roger Buick uit. “Maar het oudste fossiel is niet per se het oudste organisme dat ooit geleefd heeft, omdat de kans dat een organisme fossiliseert vrij klein is.” Onderzoek wijst nu uit dat de hoeveelheid zuurstof in de atmosfeer meer dan 1,75 miljard jaar geleden al eens sterk toenam om vervolgens – ongeveer een kwart miljard jaar later – weer af te nemen. “Dit onderzoek laat zien dat er nog voor het fossiele bewijs (voor complex leven ontstond, red.) genoeg zuurstof in de atmosfeer zat om de evolutie van complexe cellen mogelijk te maken. Het betekent niet dat dat ook echt gebeurde, maar het kan wel zijn gebeurd.”
Sedimenten Buick en collega’s trekken die conclusie nadat ze 2 tot 2,4 miljard jaar oude sedimenten bestudeerden. Ze richtten zich daarbij met name op het element seleen dat door de aanwezigheid van zuurstof beïnvloed wordt. Het onderzoek wijst uit dat er lang voor de oudste meercelligen waarvan resten zijn teruggevonden leefden, een periode was waarin de hoeveelheid zuurstof op aarde sterk toenam. En die hoeveelheid bleef ook een lange tijd hoog. Dat is belangrijk. Want de evolutie van complexe levensvormen vereist tijd. En dat was ze gegund in de eerste periode waarin de hoeveelheid zuurstof op aarde rap toenam.
Uniek Grote vraag is natuurlijk waarom de hoeveelheid zuurstof in de atmosfeer rap toenam om vervolgens een kwart miljard jaar later weer af te nemen en dus de ondergang in te luiden voor eventuele complexe levensvormen die dankzij de hogere zuurstofconcentratie waren ontstaan. Onderzoekers weten het niet. “Het is onbekend waarom het gebeurde en waarom er een einde aan kwam,” stelt onderzoeker Eva Stüeken. “Zoiets hebben we nooit meer in de aardse geschiedenis meegemaakt,” voegt Buick toe. “Als je kijkt naar de seleenisotopen door de tijd heen, dan is het een unieke interval: zowel ervoor als erna is alles anders.”
Het onderzoek vertelt niet alleen meer over de geschiedenis van de aarde, maar heeft tevens implicaties voor de zoektocht naar buitenaards leven. “De erkenning van deze periode in het verre verleden van de aarde waarin er bijna net zoveel zuurstof in de atmosfeer zat als nu het geval is, maar de bewoners heel anders waren, kan erop wijzen dat de detectie van een zuurstofrijke wereld niet direct bewijst dat er sprake is van een complexe biosfeer,” stelt onderzoeker Michael Kipp. Want hoewel het goed mogelijk is dat er meer dan 1,75 miljard jaar geleden meercellige organismen ontstonden, was deze eventuele meercelligen niet genoeg tijd gegund om te diversificeren.
Humans need to colonize another planet within 100 years or face the threat of extinction, Stephen Hawking has warned. At the beginning of 2016, Hawing warned about the dangers of nuclear war, global warming, genetically-engineered viruses, and the danger of artificial intelligence. In the new BBC documentary “Stephen Hawking: Expedition New Earth,” the professor warns that “the human race only has 100 years before we need to colonize another planet.”
“With climate change, overdue asteroid strikes, epidemics and population growth, our own planet is increasingly precarious,” Hawking adds in the film. Hawking used to believe we had about 1,000 years left, but that timeline appears to have shortened.
“Although the chance of a disaster to planet Earth in a given year may be quite low, it adds up over time, and becomes a near certainty in the next thousand or ten thousand years,” Hawking told the BBC in an interview last year. “By that time we should have spread out into space, and to other stars, so a disaster on Earth would not mean the end of the human race. However, we will not establish self-sustaining colonies in space for at least the next hundred years, so we have to be very careful in this period.”
Though Hawking’s timeline is more extreme than most, he is not the only visionary to warn about the threat to human existence. Earlier this year, Elon Musk said humans must merge with machines to avoid becoming irrelevant.
Alibaba founder Jack Ma, meanwhile, also recently warned that society could face decades of “pain” because of the disruption caused by new technology and the internet, CNBC notes.
What do you think of Hawking’s daunting prediction?
Astronomers Discover A Galaxy Made of 99.99% Dark Matter
Astronomers Discover A Galaxy Made of 99.99% Dark Matter
NASA, ESA, M.J. Jee and H. Ford
IN BRIEF
After decades of being ignored, Ultra Diffuse Galaxies (UDGs) are finally being given the attention they deserve. These galaxies have very few stars and it is believed that dark matter holds these galaxies together. Astronomers turned their sights on Dragonfly 44, a recently discovered UDG, and found that it's comprised of only 0.01% normal matter, and 99.99% dark matter.
THE INVISIBLE GLUE BEHIND ULTRA DIFFUSE GALAXIES
For years, a galaxy named Dragonfly 44 remained unnoticed despite its relative proximity to us here in the Milky Way. This wasn’t surprising, seeing as this galaxy is very dim. Last year, astronomers finally gave it the attention it deserves—and rightly so.
The reason why Dragonfly 44 was dim was because it had very few stars, making it very easy to miss. An observation of the Coma Cluster by the Dragonfly Telephoto Array led to astronomers finally seeing that there was, in fact, a galaxy hiding out there in the expanse.
Image credit: Pieter van Dokkum, Roberto Abraham, Gemini Observatory/AURA
At first, the lack of stars did strike astronomers as odd. But upon contemplation, its ability to even keep these stars at all was far more strange and interesting than the former mystery.
Why? Sparse galaxies like Dragonfly 44, called Ultra Diffuse Galaxies (UDGs), have so few stars that normal assumption would dictate these galaxies easily losing the stars they have. Without enough mass in the galaxy to generate the gravitational attraction to keep the galaxy together, these stars could easily spin out of place (and maybe even be kidnapped by neighboring gravitational forces).
The galaxy being able to keep these stars in place despite the lack of visible mass implies one thing: dark matter is the missing link keeping them together.
The two Keck Telescopes on top of Mauna Kea in Hawaii.
NASA
DRAGONFLY 44: 99.99% DARK MATTER
Dragonfly 44 was particularly astonishing: it stretches 60,000 light years across, and only .01% of it comes in the form of stars and normal matter, which would mean the remaining 99.99% is dark matter.
For this study, the astronomers calculated the galaxy’s mass and monitored how fast the stars spin in a 33.5-hour period over six nights. “Motions of the stars tell you how much matter there is,” says lead author Pieter van Dokkum. “They don’t care what form the matter is, they just tell you that it’s there. In the Dragonfly galaxy stars move very fast. So there was a huge discrepancy: using Keck Observatory, we found many times more mass indicated by the motions of the stars, then there is mass in the stars themselves.”
A galaxy made up almost entirely of dark matter was unexpected, and astronomers do not have an explanation on how they form yet. But this finding is a significant aid in the quest to unmask what dark matter actually is.
The Sombrero galaxy—an ultradiffuse galaxy also located in the Coma Cluser.
Scientists Claim To Have Found 234 Alien Civilizations
Scientists Claim To Have Found 234 Alien Civilizations
Aliens are like buses, you spend ages waiting for one and then 234 come along at once. Or at least, that’s what two astronomers from the Laval University in Quebec are suggesting.
Ermanno Borra and his graduate student Eric Trottier have analyzed over 2.5 million stars and galaxies for pulses of light emitted at regular intervals and discovered it in 234 stars similar in size to our Sun. The team believes that alien civilizations are behind those signals.
The researchers looked at the Fourier Transform (FT) of the light spectrum. The FT is a mathematical tool that allows us to work out where the components of a signal come from. If the light is a milkshake, by using the FT you get the recipe.
The FT analysis has found periodic modulated components which, according to the scientists, are caused by the super quick light pulses (less than a trillionth of a second) generated by Extraterrestrial Intelligence (ETI). In the paper, available from the Publications of the Astronomical Society of the Pacific, they discard every other explanation such as instrumental effects, rotation of molecules, rapid stellar pulsations, and peculiar chemistry.
“We find that the detected signals have exactly the shape of an ETI signal predicted in the previous publication and are therefore in agreement with this hypothesis,” the researchers wrote in the paper.
“The fact that they are only found in a very small fraction of stars within a narrow spectral range centered near the spectral type of the Sun is also in agreement with the ETI hypothesis.”
These superfast pulses will have to be generated by incredibly powerful lasers, like the one at the Lawrence Livermore National Laboratory. Interestingly, in previous publications Borra has stated that this area of astronomy is the least explored, which raises the question on why these aliens would all decide to communicate in such a complicated and energy-consuming way.
The researchers admit that although they believe aliens is the most likely explanation, this is yet to be confirmed.
The Stephen Hawking-backed project Breakthrough Listen will conduct follow-up observations of these 234 stars, but the team at UC Berkeley, where the project’s science program is based, invite people to be skeptical.
“The one in 10,000 objects with unusual spectra seen by Borra and Trottier are certainly worthy of additional study. However, extraordinary claims require extraordinary evidence. It is too early to unequivocally attribute these purported signals to the activities of extraterrestrial civilizations,” the Breakthrough Listen team said in a statement.
Voyager scientists on the Jupiter encounter, Pluto's planet status and whether we'll find extraterrestrial life
Voyager scientists on the Jupiter encounter, Pluto's planet status and whether we'll find extraterrestrial life
A collage of Jupiter and its four planet-size moons, photographed in early March 1979 by Voyager 1. The Voyager Project is managed for NASA's Office of Space Science by Jet Propulsion Laboratory, California Institute of Technology.
Along for the rides on Voyager 1 and Voyager 2 are the famous Golden Records: phonographs with music, greetings and photographs meant to give aliens an introduction to Earth and its inhabitants.
There was an advance screening of the film at the Franklin Institute in Philadelphia on Aug. 10, complete with a panel featuring Voyager mission scientists Fran Bagenal (Co-Investigator Plasma Science) and Rich Terrile (Imaging Science), as well as Nick Sagan, the son of scientist Carl Sagan. Nick Sagan gave one of the greetings on the Golden Record when he was six years old.
We spoke with Bagenal and Terrile before the screening on Facebook Live. You can watch the full interview in the video below, or just scroll past the video to read highlights.
What is the most interesting thing we've learned from Voyager?
Terrile: "I think the most interesting thing was that the solar system is far more surprising than our imaginations had led us to believe. The eye-opening thing about Voyager is we discovered that the real solar system was more like science fiction than science fact up until that point."
Bagenal: "The moons of the giant planets were all so different. We thought it'd be like our moon, very boring, kind of dull. But no... each one has a character, a special geology, a whole special formation, all sorts of different things we learnt. Everytime we went to a new place it was totally different."
When did you feel like Voyager had been successful?
Terrile: "The very first encounter with Jupiter. We knew the most about Jupiter than any other objects we've been to. We've been there before with other spacecrafts. It's closer so telescopes can see it more clearly. But at Jupiter there were just so many surprises. And as Fran said, the moons were just this incredible variety of places with erupting volcanoes, moons that the geology changes at the same timeframe the weather changes on our planet. That was just so mind blowing. That just set the stage for one incredible encounter after another."
Bagenal: "One of the most exciting images I remember seeing was in the New York Times and it was above the fold and it was a picture of Jupiter with a great red spot with the moons in front. Famous picture and I'll always have it in my mind. Going into the news agents, as they had back then, and looking in and seeing this picture was fantastic."
The Great American Solar Eclipse will move across the U.S., from northwest to southeast, on Monday, August 21.
What do you hope is the future of space exploration?
Terrile: "The future was always supposed to be something more exciting than the reality that has happened. I grew up in the '60s at the start of the space program, Apollo. If you extrapolated from what the beginnings of our space program were in 1961... by '69 we got to the moon. We had cars on the moon. We developed rendezvous docking, ability to get into orbit, space suits, all the technology we use today. It's hard to believe we're in 2017 and we don't even have the capability to go into Earth orbit with humans."
Bagenal: "I'm going to disagree with you...there's nothing that humans can do in space that robots can't do better, faster, cheaper and more effectively except tourism. I would argue that the answer is robots and the future is robots. We're going to send a whole batch of robots out there to go to all sorts of places. The next place is Europa where we're going to go look at the ice and we're going to find out whether or not there could possibly be organisms underneath, potentially life-related organisms, and whether or not there's any communication between the ocean that's underneath and the surface. That will be very exciting and we'll send robots to go do it."
Researchers at Temple University, Drexel University and University of Pennsylvania are working hard to change the world for the better. Here's how they plan to do it.
It's interesting that you mentioned tourism. I feel like that's a lot of what we hear about today when it comes to new innovations is people wanting to go and tour space and go on luxury trips. Do you feel like that's part of the future then?
Terrile: "One of the things, I worked for Jim Cameron for awhile. And we talk about what makes something dramatic. Clearly a human in space is a dramatic thing. And he put it a little differently, he said what makes it dramatic is when the protagonist is in the picture. What technology allows us to do today is to take those images and the data we get from planetary encounters and not just make that available to one person who is walking on a planetary surface, but make that available to everybody through virtual reality and the kinds of things we're going to see in the next few years.
"We're going to have that absolute visceral experience. Today, at JPL, we can put on these glasses and walk on the surface of Mars, bend down, look at the rocks and even cast shadows and leave footprints. It's an astonishing technology... that's really the future of exploring. Not just one person exploring, but all of us exploring."
Bagenal: "The example I like to give is the Juno mission I'm involved in right now, which is a spacecraft that's in orbit around Jupiter. We have a camera on that spacecraft which is a citizen's science camera. We just took a bunch of pictures of the great red spot a couple weeks ago... all of those pictures are immediately made available to the public and the public takes those pictures, they explore, play with them and then they put them back up and share them... I think this is a new world. It isn't just those of us who are lucky to be professional scientists involved in this, it's everybody."
What is one thing that you hope people learn from "The Farthest -- Voyager in Space?"
Terrile: "For one thing, the breadth and depth and impact that mission had on science, technology and everything else. It's really astonishing. It's been 40 years since we launched Voyager and it's still going and it gave us our first view of the solar system. It changed our perspective. We learned not only how to explore planets but how to explore our own ability to command spacecraft.
"Voyager was made with technology that was basically -- it was 1972 technology that was flown. I don't know if anybody remembers what it was like in 1972, but the magic that we carry around in our pockets -- cell phones -- would have been magic in those days. And computers and everything else have increased in capability in factors of several billions of time. Yet the technology that was frozen in 1972 has provided us with this incredible look."
Bagenal: "The other thing is there was a strong team of people who worked very hard and did a lot of work and were creative and came up with ways to solve problems along the way. There was a lot more human activity needed with the technology, so the teams were quite large and they worked hard together to make this all work."
The Voyager is famous for having the Golden Record. If you could put anything on it, what would you put on it today?
Terrile: "A lot more data. To think about how little data there is on a phonograph record in those days. Very clearly it's hard to condense everything about ourselves and our planet and our society to what could fit on the phonograph."
Pluto, will it ever be a planet again?
Bagenal: "It is a planet! Hey! Dwarf people are people, dwarf planets are planets... actually what was very interesting was it got everybody debating, discussing and thinking what is a planet? Everybody got discussing stuff. Actually, despite the fact I've had big arguments with Mike Brown (the professor whose discovery of Eris led to the demotion of Pluto to dwarf planet status), we're still good friends, it was all good actually because it got people discussing, debating and talking and so on and so forth."
Gallery: Close-up images of Pluto and its moons
Will we ever find evidence of life or the possibility of living organisms on other planets?
Terrile: "I think we will. If we don't find it in our solar system, which I think it is a very very good probability that it exists in our solar system, if we don't, we'll find evidence on other planets. We've found thousands of other planets and we're going to get to the point where we can look for signatures of life."
Bagenal: "It's tough. Looking for life isn't easy. It's not going to be the first mission to Europa (one of Jupiter's moons) that will find it, probably. It may be two or three later down the road. But it's a good chance. Enceladus (the sixth moon of Saturn) is another place, perhaps Titan (another one of Saturn's moons). I think Mars is overrated, personally."
Terrile: "Mars may have had life... and certainly, if Mars had a viable environment. And we know Mars and Earth exchanged material."
Bagenal: "Right. It's probably just slime, nothing very exciting."
Terrile: "A habitable environment early on could have had at least Earth life on it."
Bagenal: "Yeah, but it probably didn't wiggle."
Terrile: "And if life started on Mars, then maybe that life showed up on our planet. Maybe we're Martians. These are the kind of questions that are actually valid in astrobiology."
Bagenal: "It is true. The exchange of material between the planets, we're just beginning to explore the possibilities and ideas."
The exoplanet system TRAPPIST-1 is about 40 light years (235 trillion miles) from Earth
Do you feel the fact we've haven't gone to space in a while is a challenge for the next generation?
Bagenal: "We have via robots. I see people excited by seeing what's happening on all the many robots we have on many planets around our solar system and what we're seeing with telescopes out further and beyond. I think what's exciting about the next generation is to go look at all these other places we've not been to yet and to use these robotic explorers to develop and find out more about these places.
"It's a challenge, because the technology is difficult and you have to make it work -- but it's a good challenge."
Terrile: "I also think we're seeing an erosion of science where people try to politicize it for their own needs, with things like climate change. They'll say 'oh those scientists, they have their own agenda. They're like the pharmaceutical industry or these other groups' but we're not. We're out to find the truth. We're out to explore. And whatever answer comes out, that's the answer. That's the truth. We're very careful about that. When the truth hurts, when the truth is not something that is politically viable, I'm afraid that people cash out on us for that."
What is a question you always wish people ask you about your work, but never do?
Bagenal: "I think some of the motivation, our own insight and drive. We sort-of talked a little bit about how we got into the science, but now what motivates me is seeing the excitement in the public arena. They're excited by what they see and what they learn... That gives me a lot of pleasure now, in seeing that people are excited by science, thinking about how to communicate science and how to show people the excitement of working in science and not having them frightened about science and that they can be involved in science and do these things too."
Terrile: "A lot of us are very, very lucky. Most people work jobs and it's their jobs, it's something they do. For most of us in this arena, we would do this work if we weren't being paid for it. It's an absolutely pleasure. It's an honor to do the work we do. It's really, really fun."
"The Farthest -- Voyager in Space" airs at 9 p.m. on Aug. 23 on your local PBS station. For more information visit pbs.org.
This story has been updated to correct the spelling of Rich Terrile's name.
Intelligent life goes extinct shortly after becoming technologically advanced and that’s why we haven’t been able to connect with any alien species, one scientist is arguing.
At the center of his assertion is the mediocrity principle, which is popular among astronomers and dictates that there is nothing special about our species, our planet or our solar system — that everything that went into the evolution of human life on Earth could have happened in other places as well. It thus also dictates that the state in which we find ourselves is completely typical and can be generally applied to the rest of the universe.
University of Arkansas professor Daniel Whitmire is suggesting that if we go by this principle, it stands to reason that any technological species would find themselves in a similar situation to humans on Earth: “that they are both the first such species to evolve on their planet and also that they are early in their potential technological evolution,” according to his paper in the International Journal of Astrobiology. He argues that this implies intelligent species do not exist further along in technological evolution because they have gone “extinct soon after attaining a modern technology and that this event results in the extinction of the planet’s global biosphere.”
The exact details of how technologically advanced life on another planet evolved, like how long it took for it to emerge, are not relevant, Whitmire says. All that matter is that this life has developed electronic devices as well as technology that can affect the environment.
“A technological dinosaur species that evolved in 100 [million years] on a Mars-sized planet could still be first and early in their technological evolution,” the study says. “If we are typical of this reference class, then other members would, like us, observe that their technological species is the first to evolve on their planet and also that they are early in their potential technological evolution.”
Kepler-186f is the first exoplanet scientists discovered in a star’s habitable zone that is comparable to the size of Earth.
Photo: NASA/JPL
Those species very well could have been the first on their planets to become advanced, rather than rising from the ashes of another technologically advanced group of beings, based on how it happened on Earth — the study notes that the timeline for how humans emerged and created technology leaves enough room for there to have been another similar species before us on Earth, but that didn’t happen.
The point at which humans became technological, according to this study, was about 100 years ago, after the industrial revolution and the radio burst onto the scene.
“According to the principle of mediocrity, a bell curve of the ages of all extant technological civilizations in the universe would put us in the middle 95 percent,” the University of Arkansas explains. “In other words, technological civilizations that last millions of years, or longer, would be highly atypical.”
That leads to the questions of why there should be only civilizations in which the inhabitants are new to technology and are the first on their planet to get that far.
If we assume the evolution and development of humans is typical, it follows that alien species like us were also the first on their planet — and thus “once species become technological, they flame out and take the biosphere with them,” the university says. The latter part, about the demise of the rest of the biosphere, is crucial to preventing other technologically advanced species cropping up on the same planet.
The other option is that humans and Earth are among the outliers, in which case Whitmire asserts that “by statistics, we have to be the dumbest guys in the galaxy. After all we have only been technological for about 100 years while other civilizations could be more technologically advanced than us by millions or billions of years.”
SETI doesn’t just believe in aliens. They believe aliens are broadcasting via radio signals and lasers everywhere—and that you could possibly find them.
The SETI (Searth for ExtraTerrestrial Intelligence) Institute’s newest crowdfunding campaign knows they’re out there, and that so many must be out there that if everyone has E.T.’s on their radar 24/7, they could finally find something that isn’t a false alarm from a telemetry signal that ran into their radio telescope at 3 in the morning. Called “Laser SETI: First-Ever All-Sky All-the-Time-Search,” the project is getting a boost from an Indiegogo crowdfunding campaign that is blasting off towards $100,000.
The things you see on Indiegogo never cease to amaze me.
While Laser SETI will still need hi-res cameras and optics designed for astronomy if this thing is going to take off, it’s still exponentially more cost effective than sending satellites to every known corner of the universe. We are just microbes in a universe so vast that just about anything could be hiding in places so far away that they haven’t even been reached by satellites or seen by even the most powerful telescopic eyes from Earth or space. It’s also hard to believe that there isn’t anything else crawling around when our universe is 14 billion years old, which is more than enough time for just about anything, intelligent or otherwise, to evolve.
“It's very difficult to imagine that we are alone,” said SETI CEO Bill Diamond for these reasons. “Yet extraterrestrial life still eludes our efforts to find it. Now you have a chance to be a part of the technology that can change that forever."
SETI assumes that aliens are always on air. Whether they are trying to reach us with superpowered lasers, monster radio transmitters or anything else our Earthling brains might have not even dreamed up yet remains to be seen. There have been previous doubts about extraterrestrial beings anywhere from hundreds to billions of light-years away trying to target a planet they don’t even know exists. The idea may strike you as a kind of reverse X-Files.
Laser SETI is the first endeavor to defy this thinking "because it's designed to find a very short ping that doesn't stay on all the time — it can detect a laser flash as short as a microsecond, and one that might not repeat for days, weeks, or even longer," as Diamond explained.
Now watch the video, then take off to the campaign and donate. For science.
A new study explains how alien planets might skip straight from being too cold to support life to being too hot, without ever becoming habitable. That could trim the number of planets we should investigate for life.
This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. The TRAPPIST-1 planets orbit their star extremely closely, with periods ranging from 1.5 to only about 20 days. This is much shorter than the period of Mercury, which orbits our sun in about 88 days.
TRAPPIST-1 Comparison to Solar System and Jovian Moons
IN THE ZONE
Earth’s location in space is perfect: not too close to but not too far from the Sun, it gives our planet the balmy temperature that helps supports life. However, a new study suggests that it might be even more difficult than previously expected to find a celestial body that falls within this ‘Goldilocks zone.’
The habitable zone of any given star is the area where planets can maintain a temperature that allows liquid water to be found on its surface. Too close to the star, and that water will turn to vapor — too far away, and it’ll turn to ice.
However, stars like our sun gradually get more luminous over time, which changes the parameters of their habitable zone. This means that icy planets can feasibly reach a point where their conditions are warm enough to support life — but according to a recent study in Nature Geoscience, that’s not always the way the situation will pan out.
TOO HOT TO HANDLE
A planet’s ability to support life-sustaining temperatures hinges on at least two factors: the amount of ice on the surface, and the amount of greenhouse gases being released into its atmosphere. Yet many icy planets don’t have the volcanic activity needed to contain any greenhouse gases besides water vapor.
So this study’s team, led by Jun Yang of Peking University, developed a model that could simulate how the climate of an ice-covered planet with only water vapor in the atmosphere would change over time. The results suggested it would take 10 to 40 percent more energy than the Earth receives from the sun before they began to melt.
Without ice to reflect incoming heat, this heat-intensive process was often followed by a speedy uptick in temperature that caused the planet’s oceans to boil off. And without water, these worlds wouldn’t be able to support life after all.
This isn’t necessarily bad news. Thanks to increasingly sharp-eyed instruments, the number of known exoplanets has skyrocketed in the past two decades, from a mere handful in the mid-90s to nearly 2000 today. In February 2014 alone, NASA announced a “planet bonanza” discovery of 715 new planets, found by the Kepler satellite. But identifying which of these distant worlds might be friendly to life is still tricky.
Scientists are able to infer the atmospheric content of a planet based on the way light passes through it, a process that’s already been used to detect water on a distant Earth-sized planet. However, this method doesn’t tell scientists what else is happening on the planet — such as whether it’s in the runaway, ocean-boiling cycle Yang’s team identified.
If we’re on the search for a planet that humans can live on, having this information at hand gives us more insight into which worlds are in contention.
Magnetisch veld van de maan hield langer stand dan gedacht
Magnetisch veld van de maan hield langer stand dan gedacht
Caroline Kraaijvanger
Het voor de leefbaarheid van manen en planeten zo belangrijke magnetische veld ging tot wel 2,5 miljard jaar langer mee dan aangenomen.
Die conclusie trekken onderzoekers nadat ze maangesteente dat astronauten tijdens de Apollo 15-missie naar de aarde brachten, bestudeerden. Het gaat om een kleine, jonge steen die waarschijnlijk ontstond tijdens een meteorietinslag die zo’n 1 tot 2,5 miljard jaar geleden plaatsvond.
Elektronen We weten dat de maan in het verleden een magnetisch veld heeft gehad. En dat magnetisch veld laat zijn sporen na in vloeibare gesteenten die aan het magnetisch veld zijn blootgesteld. In die vloeibare gesteenten zitten namelijk elektronen wiens richting bepaald wordt door het magnetisch veld. Wanneer het vloeibare gesteente vervolgens afkoelt, getuigen de elektronen in het gesteente voor altijd van het magnetisch veld dat tijdens het ontstaan van het gesteente heer en meester was.
Apollo-15 Grote vraag was natuurlijk of het magnetisch veld van de maan nog een rol speelde in de tijd dat de maansteen die tijdens de Apollo 15-missie was gevonden, ontstond. Dat is nog niet zo heel gemakkelijk vast te stellen. Om de oorspronkelijke magnetisatie van de steen te achterhalen, moest deze in een ruimte met een gecontroleerde atmosfeer verhit worden. Iets wat nog niet eerder met succes was gedaan. Tot nu. Onderzoeker Sonia Tikoo slaagde erin om middels verhitting het magnetisch veld waar de steen tijdens zijn oorsprong aan is blootgesteld, te meten. En de resultaten zijn verrassend. Toen deze steen 1 tot 2,5 miljard jaar geleden ontstond, had het magnetisch veld van de maan nog een sterkte van zo’n 5 microtesla (ongeveer 10 procent van de kracht van het huidige aardmagnetisch veld).
Magnetisch veld ging langer mee Eerder onderzoek had aangetoond dat de maan in een ver verleden (meer dan 3,5 miljard jaar terug) een krachtig magnetisch veld had. Maar de ondergang van het magnetisch veld zou zo’n 3,5 miljard jaar geleden zijn ingezet, toen de intensiteit rap afnam. Dit onderzoek laat echter zien dat het magnetisch veld van de maan 1 tot 2,5 miljard jaar geleden nog tamelijk krachtig was en dat het magnetisch veld dus tot wel 2,5 miljard jaar langer meeging dan gedacht.
De kern van de maan De bevindingen hebben tal van implicaties. Zo kan het onze kijk op de kern van de maan veranderen. “We dachten dat kleine planetaire lichamen niet heel lang een magnetisch veld konden genereren, omdat ze kleine kernen hebben die snel afkoelen en al vroeg kristalliseren,” stelt Tikoo. De ideeën die we nu hebben over de samenstelling van de kern van de maan kunnen door dit onderzoek dan wel eens op losse schroeven komen te staan, aangezien de snelheid waarmee een kern kristalliseert afhankelijk is van diens samenstelling. “Het (de kern van de maan, red.) bestaat voornamelijk uit ijzer, maar er moet nog meer in zitten: zwavel, koolstof of een ander element.”
Daarnaast heeft het onderzoek ook implicaties voor de leefbaarheid van andere manen en planeten. Wanneer een hemellichaam zijn magnetisch veld kwijtraakt, kunnen ioniserende deeltjes van de zon het hemellichaam rap van zijn water ontdoen. En dat heeft weer gevolgen voor de leefbaarheid van zo’n planeet of maan. Zoiets overkwam bijvoorbeeld Mars dat veel water bezat, maar het kwijtraakte toen het magnetisch veld zo’n 4 miljard jaar geleden verdween. “Wanneer we kijken naar exoplaneten of de manen van exoplaneten die zich mogelijk in een leefbare zone bevinden, moeten we bij het beoordelen van de leefbaarheid ook rekening houden met het magnetisch veld,” vindt Tikoo. “De vraag is dan hoe groot planeten en manen moeten zijn om ze als potentieel leefbaar te kunnen bestempelen.”
Zestien meter grote planetoïde scheert in oktober vlak langs de aarde
Zestien meter grote planetoïde scheert in oktober vlak langs de aarde
Tim Kraaijvanger
De planetoïde 2012 TC4 schiet over twee maanden rakelings langs de aarde. Op 12 oktober bedraagt de afstand tussen dit object en onze planeet slechts 44.000 kilometer.
2012 TC4 is al in 2012 ontdekt door het Pan-STARRS observatorium op Hawaï, maar is nu opnieuw gevonden door ESO’s Very Large Telescope in Chili. In 2012 scheerde de asteroïde op een afstand van zo’n 96.000 kilometer langs de aarde. Astronomen wisten in dat jaar al dat de planetoïde in oktober 2017 opnieuw in de buurt van de aarde zou komen, maar slaagden er niet in om de exacte route in kaart te brengen. Logisch ook, want een ruimtesteentje met een doorsnee van zestien meter is lastig te volgen.
Omdat de afstand tot 2012 TC4 in oktober slechts 44.000 kilometer is, hopen astronomen meer te weten te komen over het object. Wellicht lukt het om informatie te verzamelen over de samenstelling van de planetoïde.
Stel dat 2012 TC4 in de toekomst in botsing komt met de aarde, dan vormt dit gelukkig geen groot gevaar voor de mensheid. In 2013 verbrandde er een twintig meter grote planetoïde boven het Russische Tsjeljabinsk. Wetenschappers vermoeden dat 4000 tot 6000 kilo puin van de meteoriet het aardoppervlak haalde. Wanneer planetoïde 2012 TC4 ooit in de atmosfeer terechtkomt, dan is het effect ongeveer gelijk.
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Over mijzelf
Ik ben Pieter, en gebruik soms ook wel de schuilnaam Peter2011.
Ik ben een man en woon in Linter (België) en mijn beroep is Ik ben op rust..
Ik ben geboren op 18/10/1950 en ben nu dus 66 jaar jong.
Mijn hobby's zijn: Ufologie en andere esoterische onderwerpen.
Op deze blog vind je onder artikels, werk van mezelf. Mijn dank gaat ook naar André, Ingrid, Oliver, Paul, Vincent, Georges Filer en MUFON voor de bijdragen voor de verschillende categorieën...
Veel leesplezier en geef je mening over deze blog.
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