By Chris Eberhart Fox News

Video

Let’s have ‘transparency’ on UFOs: Rep. Tim Burchett

Rep. Tim Burchett, R-Tenn., discusses his push for answers on UFO information on ‘The Story.’

FIRST ON FOX: The U.S. government would have 270 days to release all UFO-related documents to the public if a new congressional bill is passed. 

Rep. Tim Burchett, R-Tenn., who has been a leading voice for UFO transparency, will introduce a new bill Thursday that would require President Biden to direct the heads of each federal department or agency to declassify all documents related to UAPs (unidentified anomalous phenomena), also known as UFOs. 

"It's simple. They spend all this time telling us they don't exist, then release the files, dagnabbit," Burchet told Fox News Digital in an interview, before introducing the "The UAP Transparency Act" on Thursday.

"I don't want some crazy, fancy name for it," he said. "I just want them to do exactly what the bill is about."

UNDERWATER UFOS DISPLAY CAPABILITY THAT ‘JEOPARDIZES' US MARITIME SECURITY,’ EX-NAVY OFFICER SAYS

Rep. Tim Burchett, R-Tenn., participates in a meeting of the House Oversight and Reform Committee in the Rayburn House Office Building on January 31, 2023, in Washington, D.C.  

(Kevin Dietsch/Getty Images)

Rep. Burchett has been at the forefront of the fight for UFO transparency, along with several other Republicans in the House and Senate, but there has been a bipartisan effort. 

Rep. Anna Paulina Luna, R-Fla., and Jared Moskowitz, D-Fla., are co-sponsors of the bill. 

In a previous interview, Burchett said he believes there has been a cover-up, and that tens of millions of dollars are being spent "on something that you say doesn't exist, (and) yet you continue spending the money on it. It makes you wonder."

• LAS VEGAS ALIEN VIDEO'S PREVIOUSLY MISSED DETAIL PROVES ‘AUTHENTICITY,’ EXPERT SAYS: ‘YOU CAN’T DENY IT'

The 1.5-page bill would not only force the president to direct federal agencies to declassify UFO-related files, but it would require the president to file quarterly reports that would update the House and Senate subcommittees on the progress toward releasing the information. 

"That's all it is," Burchett said. "It's about transparency."

Recording of a UFO flying by the USS Omaha off the coast of San Diego in July 2019 and then vanishing into the ocean without a splash or crash debris. 

(Jeremy Corbell/Weaponized Podcast)

WATCH: 'JELLYFISH UAP' FLIES OVER IRAQ 

Video

Burchett and other lawmakers have been frustrated by the bureaucrats' diversion tactics and stonewalling, while millions of dollars seemingly vanish into a black hole. 

"Like I said before, it's not about little green men or flying saucers," he told Fox News Digital in an April interview, "it's about tens of millions of dollars that our federal government is spending on something that at least some of the members of the federal government say does not exist. Yet, they will not release all the files."

• RUSSIAN UFO ENGAGEMENTS, SECRET ‘TIC TAC’ REPORT AND 3 KEY FIGURES SLIP UNDER RADAR AT CONGRESSIONAL HEARING

To the Republican lawmakers' point, as recently as February 2021, an Intelligence Community Control Access program "was expanded to protect UAP reverse-engineering … without sufficient justification," the Pentagon's February report on UFOs said.

"This program never recovered or reverse-engineered any UAP or extraterrestrial spacecraft. This IC (intelligence community) program was disestablished due to its lack of merit," according to the report. 

"It's simple. They spend all this time telling us they don't exist, then release the files, dagnabbit."

— Rep. Tim Burchett

WATCH: REP. BURCHETT TALKS ABOUT WHY HE THINKS THERE'S A UFO COVER-UP

Video

Last month, there were about a dozen people (including Burchett) in a SCIF, a sensitive compartmented information facility, about UFOs, which is a highly classified briefing, and he left feeling "discouraged, as all this other stuff is."

He didn't see why the information discussed in the SCIF couldn't have been discussed in a public setting. 

"I really think the whole thing is so compartmentalized that we'll never get to the bottom of it until you have a commander-in-chief who says enough is enough," he said.

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Instead of waiting for the executive branch, this short but pointed bill would essentially merge all the compartmentalized federal agency files and dump them into one declassified pool of information. 

"We just got to put this stuff out. Let's clear the air. And let's move on," Burchett said. 

Chris Eberhart is a crime and US news reporter for Fox News Digital. Email tips to chris.eberhart@fox.com or on Twitter @ChrisEberhart48.

{ https://www.foxnews.com/ }

17-05-2024 om 01:02 geschreven door peter  

Ontdekking op onze buurplaneet kan hoop bieden op voorwaarden voor leven

Wetenschappers vinden de ontdekking van een bepaald element in gesteente op Mars opmerkelijk.

Al meer dan 10 jaar rijdt NASA’s Marsrover Curiosity rond om monsters te nemen van grond en gesteente. Zo wil NASA erachter komen of de omstandigheden op de planeet ooit gunstig waren voor leven.

In 2018 vond de rover moleculen die belangrijke bouwstenen zijn voor leven zoals we dat op aarde kennen.

En nu heeft de Curiosity mineralen in gesteente ontdekt die lijken op mineralen op aarde, wat bewijs kan zijn dat Mars vroeger leven kon herbergen.

Hoge concentraties gevonden

De onderzoekers beschrijven dat er een ongewoon hoog gehalte van het element mangaan is gevonden.

In het artikel, dat is gepubliceerd in het tijdschrift JGR Planet schrijven ze dat die hoge concentraties zijn gevonden in een gebied waar volgens hen ooit een meer was.

In een persbericht zegt Patrick Gasda van Los Alamos National Laboratory dat ze niet hadden verwacht mangaan in zulke hoge concentraties aan te treffen.

Hij legt uit dat afzettingen zoals ze die op Mars hebben gevonden op aarde voorkomen omdat er een hoog zuurstofgehalte is.

‘Op Mars is er geen bewijs van leven, en de mechanismen om zuurstof in de atmosfeer te produceren zijn onduidelijk. Hoe mangaanoxide is ontstaan en hoe de concentratie ervan is toegenomen, is een mysterie,’ schrijft Gasda.

Gesteente onthult leefbaar milieu

De metingen in Galekrater zijn gedaan met de Chemcam-apparatuur van de Curiosity.

‘Het milieu bij het Galemeer lijkt verrassend veel op bepaalde plaatsen op aarde, wat suggereert dat het leefbaar kan zijn geweest,’ voegt de leider van het Chemcam-onderzoek, Nina Lanza, eraan toe.

Ze legt uit dat mangaanmineralen vaak worden aangetroffen aan de oevers van ondiepe meren, maar dat het een opmerkelijke vondst is in oud gesteente op Mars.

{ https://wibnet.nl/heelal }

15-05-2024 om 23:35 geschreven door peter  

Finding seven of them in one system is a unique scientific opportunity to examine all kinds of interlinked questions about exoplanet habitability. TRAPPIST-1 is a red dwarf, and one of the most prominent questions about exoplanet habitability concerns red dwarfs (M dwarfs.) Do these stars and their powerful flares drive the atmospheres away from their planets?

New research in the Planetary Science Journal examines atmospheric escape on the TRAPPIST-1 planets. Its title is “The Implications of Thermal Hydrodynamic Atmospheric Escape on the TRAPPIST-1 Planets.” Megan Gialluca, a graduate student in the Department of Astronomy and Astrobiology Program at the University of Washington, is the lead author.

Most stars in the Milky Way are M dwarfs. As the TRAPPIST-1 makes clear, they can host many terrestrial planets. Large, Jupiter-size planets are comparatively rare around these types of stars.

It’s a distinct possibility that most terrestrial planets are in orbit around M dwarfs.

But M dwarf flaring is a known issue. Though M dwarfs are far less massive than our Sun, their flares are way more energetic than anything that comes from the Sun. Some M dwarf flares can double the star’s brightness in only minutes.

Another problem is tidal locking. Since M dwarfs emit less energy, their habitable zones are much closer than the zones around a main sequence star like our Sun. That means potentially habitable planets are much more likely to be tidally locked to their stars.

That creates a whole host of obstacles to habitability. One side of the planet would bear the brunt of the flaring and be warmed, while the other side would be perpetually dark and cold. If there’s an atmosphere, there could be extremely powerful winds.

“As M dwarfs are the most common stars in our local stellar neighbourhood, whether their planetary systems can harbour life is a key question in astrobiology that may be amenable to observational tests in the near term,” the authors write. “Terrestrial planetary targets of interest for atmospheric characterization with M dwarf hosts may be accessible with the JWST,” they explain. They also point out that future large ground-based telescopes like the European Extremely Large Telescope and the Giant Magellan Telescope could help, too, but they’re years away from being operational.

Red dwarfs and their planets are easier to observe than other stars and their planets. Red dwarfs are small and dim, meaning their light doesn’t drown out planets as much as other main-sequence stars do. But despite their lower luminosity and small size, they present challenges to habitability.

M dwarfs have a longer pre-main-sequence phase than other stars and are at their brightest during this time. Once they’re on the main sequence, they have heightened stellar activity compared to stars like our Sun. These factors can both drive atmospheres away from nearby planets. Even without flaring, the closest planet to TRAPPIST-1 (T-1 hereafter) receives four times more radiation than Earth.

“In addition to luminosity evolution, heightened stellar activity also increases the stellar XUV of M dwarf stars, which enhances atmospheric loss,” the authors write. This can also make it difficult to understand the spectra from planetary atmospheres by creating false positives of biosignatures. Exoplanets around M dwarfs are expected to have thick atmospheres dominated by abiotic oxygen.

Despite the challenges, the T-1 system is a great opportunity to study M dwarfs, atmospheric escape, and rocky planet habitability. “TRAPPIST-1 is a high-priority target for JWST General and Guaranteed Time Observations,” the authors write. The JWST has observed parts of the T-1 system, and that data is part of this work.

In this work, the researchers simulated early atmospheres for each of the TRAPPIST-1 (T-1 hereafter) planets, including different initial water amounts expressed in Terrestrial Oceans (TO.) They also modelled different amounts of stellar radiation over time. Their simulations used the most recent data for the T-1 planets and used a variety of different planetary evolution tracks.

The results are not good, especially for the planets closest to the red dwarf.

“We find the interior planets T1-b, c, and d are likely desiccated for all but the largest initial water contents (>60, 50, and 30 TO, respectively) and are at the greatest risk of complete atmospheric loss due to their proximity to the host star,” the researchers explain. However, depending on their initial TO, they could retain significant oxygen. That oxygen could be a false positive for biosignatures.

The outer planets fare a little better. They could retain some of their water unless their initial water was low at about 1 TO. “We find T1-e, f, g, and h lose, at most, approximately 8.0, 4.8, 3.4, and 0.8 TO, respectively,” they write. These outer planets probably have more oxygen than the inner planets, too. Since T1-e, f, and g are in the star’s habitable zone, it’s an intriguing result.

T-1c is of particular interest because, in their simulations, it retains the most atmospheric oxygen regardless of whether the initial TO was high or low.

The potential habitability of T-1 planets is an important question in exoplanet science. The type of star, the number of rocky planets, and the ease of observation all place it at the top of the list of observational targets. We’ll never really understand exoplanet habitability if we can’t understand this system. The only way to understand it better is to observe it more thoroughly.

“These conclusions motivate follow-up observations to search for the presence of water vapour or oxygen on T1-c and future observations of the outer planets in the TRAPPIST-1 system, which may possess substantial water,” the authors write in their conclusion.

{ https://www.universetoday.com/ }

15-05-2024 om 23:29 geschreven door peter  

WASP-139b is de helft groter dan Jupiter, maar heeft een massa die zeven keer kleiner is. De "dichtheid" van de planeet is dus minimaal, 0,059 gram per kubieke centimeter om precies te zijn. Ter vergelijking: de dichtheid van water is bijna één gram per kubieke centimeter, bijna twintig keer zo veel.

"Hij is zo licht dat het moeilijk was om aan een vergelijkbare vaste materie te denken", zegt Julien de Wit, professor op Massachusetts Institute of Technology (MIT) en een van de ontdekkers. Enter de suikerspin of de paardenbloem.

De planeet werd vorig jaar ontdekt. Onderzoekers hielden een ster, op een afstand van 1.200 lichtjaren, in het oog met het observatorium WASP (Wide Angle Search for Planets) en zagen dat die met momenten minder licht leek te geven. Er moest dus iets in de weg zitten van dat licht: een planeet die rond de ster draaide, telkens op iets meer dan 6 dagen. 

Kosmisch mysterie

Na die ontdekking gingen ze met andere meetinstrumenten aan de slag om in te schatten hoe groot de planeet is en hoeveel die weegt. Extreem weinig dus, en dat stelt de onderzoekers voor een raadsel. 

Ze vermoeden dat de planeet uit gassen bestaat, waterstof en helium, zoals andere zogenaamde "gasreuzen". In dit geval is de planeet zo "opgeblazen" dat haar atmosfeer tienduizenden kilometers verder reikt dan die van Jupiter, die nochtans bekend staat voor de wolkachtige atmosfeer. 

Jupiter, de planeet rechtsboven, heeft ook een redelijk lage dichtheid en is herkenbaar aan de wolkachtige atmosfeer

© Foto: Belga

"We kunnen niet verklaren hoe deze planeet zich heeft gevormd", zegt Francisco Pozuelos, een van de auteurs en onder meer verbonden aan de Universiteit van Luik. Er is geen enkele bestaande theorie die dat op dit moment verklaart. "Het is een kosmisch mysterie", besluiten de wetenschappers. Op de website van de Amerikaanse ruimteorganisatie NASA kan je een illustratie en meer info vinden. 

{ https://www.msn.com/nl-be/ }

15-05-2024 om 23:29 geschreven door peter  

Altijd al willen weten hoe het is om in een zwart gat te duiken? NASA komt met indrukwekkende simulatie

Jeannette Kras

{ https://scientias.nl/ }

15-05-2024 om 14:14 geschreven door peter  

Het onmisbare spektakel van het Noorderlicht die de wereld verbaasde met de geomagnetische storm

 Door Janine

De snelle opeenvolging van krachtige zonnestormen van de afgelopen dagen heeft de hemel van ons noordelijk halfrond beschilderd en ons een prachtig Noorderlicht gegeven. Maar hoe ontstaat dit fenomeen?

Noorderlicht en Zuiderlicht, het “geschenk” van de zonneactiviteit

NOAA Space Weather Prediction Center

De afgelopen dagen heeft de geomagnetische storm die werd veroorzaakt door de voortdurende zonnevlammen als gevolg van de inkomende piekactiviteit van de zon, die een cyclus van elf jaar heeft, niet alleen radio- en communicatieproblemen veroorzaakt in verschillende delen van de wereld, maar ook burgers van de VS, Canada, Europa en China in staat gesteld om getuige te zijn van een uniek en uiterst indrukwekkend natuurspektakel: het Noorderlicht.

De gekleurde halo's aan de nachtelijke hemel - zichtbaar door de afwezigheid van zonlicht - waren meerdere dagen zichtbaar. Het Noorderlicht is het resultaat van een moleculaire botsing in de bovenste lagen van de atmosfeer van de aarde, die uitbarstingen van energie veroorzaakt. Deze energie manifesteert zich in zichtbaar licht aan de hemel, maar dat kunnen we alleen opmerken in de uren dat het donker is. Maar het is niet het enige dat verbaasde toeschouwers betovert: er is ook de aurora australis (Zuiderlicht), die voorkomt op het zuidelijk halfrond en in de eerste helft van het jaar zichtbaar is in sommige regio's in de buurt van de twee aardpolen.

De sterkste zonnestorm sinds decennia

Het poollicht beweegt zich van de polen naar de evenaar tijdens perioden van maximale activiteit, zoals de afgelopen dagen het geval was. De krachtige geomagnetische storm heeft onze planeet bereikt en ontketende spectaculaire nachtelijke spektakels over de hele wereld. Dit is een historische gebeurtenis: op 10 mei bereikte de storm het hoogste niveau op de schaal die begint met G1 en classificeerde zichzelf als G5, kondigde NOAA, de National Oceanic and Atmospheric Administration, aan. Dit is in tientallen jaren niet gebeurd.

Na een reeks coronale massa ejecties, materiaal dat uit de corona van de zon wordt uitgestoten en deze fenomenen kan veroorzaken, werd de hemel een heel weekend lang overspoeld door Noorderlicht, zoals het Space Weather Prediction Center van NOAA aankondigde. De zonnestorm was de sterkste in twee decennia, door de krachtige geladen energieën die vanaf de zon de ruimte in explodeerden. Hoewel het geen gevaar voor ons vormt, kan het elektronische apparaten aantasten, waaronder satellieten in een baan om de aarde.

Hoe het Noorderlicht ontstaat

Dan McManus - SPACE WEATHER PREDICTION CENTER/NOAA

Brian Cox, natuurkundige en ruimtevaartdeskundige, zei: "Zonder het magnetische veld van de aarde dat ons beschermt, zou onze atmosfeer allang verloren zijn gegaan in de ruimte. Die kleuren aan de hemel herinneren de natuur ons eraan dat we blij mogen zijn dat we hier zijn."

De afgelopen jaren hebben we een zeer actieve zon meegemaakt, met talloze coronale massa-uitbarstingen die op onze planeet gericht waren. Juist hierdoor kunnen we de poollichten zien: de coronale massa-uitstoot lanceert geladen deeltjes de ruimte in, die wanneer ze de gassen van de atmosfeer van de aarde raken, zoals zuurstof en stikstof, deze prachtige lichten doen ontstaan. Zuurstofatomen worden groen, stikstofatomen worden blauw, roze en violet.

De hemel heeft zo voor wonderbaarlijke verrassingen gezorgd, die heel veilig met het blote oog zichtbaar waren.

{ https://www.curioctopus.nl/ }

15-05-2024 om 12:21 geschreven door peter  

'God of Destruction' asteroid Apophis will come to Earth in 2029 — and it could meet some tiny spacecraft

As to why Apophis is an apt target for a planetary defense study? Well, discovered in 2004, the asteroid quickly rose to the top of tables that measure the risk of so-called potentially hazardous asteroids (PHAs), or asteroids with widths of 460 feet (140 meters) or more that come within 20 lunar distances of Earth.

Both the size of Apophis and how close to Earth its trajectory brings it saw the asteroid remain at the top of both the European Space Agency's (ESA's) "impact risk list" of PHAs and NASA's Sentry Risk Table for 17 years. That was until a close flyby of the asteroid — a space rock that is almost as wide as the Empire State Building is tall — in March 2021 allowed NASA scientists to determine Apophis actually won't hit the Earth for at least 100 years. 

Though we now know Apophis won't collide with Earth in the next century, its scientific impact in 2029 will still be tremendous, and space agencies from countries across the globe will be closely tracking its trajectory.

Plus, as an asteroid that formed around the same time as the planets from leftover material around the infant sun, Apophis also offers researchers a unique opportunity to determine what the solar system's chemical composition was around 4.6 billion years ago

Meet the rendezvous candidates

Despite the fact that we are aware of around 1.3 million asteroids in the solar system, of which 2,500 are considered potentially hazardous (though none are expected to hit Earth for at least a century), spacecraft missions to study asteroids are relatively rare.

Thus far, only 20 missions have been deployed to study asteroids in situ, including the aforementioned OSIRIS-REx, Japan's Hayabusa1 and Hayabusa2 crafts, the ESA's Rosetta space probe, and the asteroid-hopping NASA mission Lucy, currently journeying to the Trojan asteroids that share their orbit with Jupiter.  Thus, the JMU team must carefully consider its options when considering a future asteroid-investigating spacecraft. 

The team's first concept is a small satellite that will join Apophis for a period of two months as it makes its close approach to Earth in April 2029. The craft will stick with the "God of Destruction" space rock for weeks after, even as it moves away. Over the course of the mission, this German national spacecraft will photograph Apophis and make measurements documenting any changes the NEA undergoes during its flyby.

This particular mission would be a challenging one because of its duration, the distance it will be required to travel, and the fact that the craft will have to function autonomously for long periods. It would also have to launch at least a year before Apophis arrives in Earth's vicinity.

The team's second concept involves integration with a larger spacecraft that's being planned by the ESA called RAMSES. This mission will be outfitted with smaller satellites, measuring equipment and telescopes. RAMSES, named after Egyptian pharaoh Ramesses the Great, would journey to Apophis and stay with the asteroid as it passes Earth.

If the second concept reaches fruition, one of the small satellites carried by RAMSES will be designed by the JMU team, with this project requiring less technical effort than the first concept while promising to reap greater scientific knowledge. 

One of the primary issues the second concept faces, however, has to do with getting REMESES off the ground — not literally, but figuratively. It's success will depend on the willingness of ESA partner countries to fund the mission. Again, a lead time of at least 365 days would be needed to ensure the success of this concept.

The third concept involves a small satellite that will only briefly fly past Apophis when the asteroid is at its absolute closest to Earth, snapping images of the asteroid in the process. This concept would require much less effort, and the craft would be relatively inexpensive.

The downside of concept 3, however, is that its observation time would be limited, which would also limit the volume of knowledge this mission would add to our understanding of asteroids.

On the plus side, the small-scale mission could launch just two days before Apophis arrives. Also, if concept 3 were to successfully observe Apophis, it would demonstrate the capability of small and inexpensive satellites in studying asteroids, perhaps leading to an increased interest for in situ asteroid-studying missions going forward.

The NEAlight project kicked off at the beginning of May 2024; between now and April 30, 2025, the JMU scientists will work out the requirements and specificities of the respective missions.

Beyond the visit of Apophis, the three concepts considered could remain options for future missions to other solar system planets, the moon — or maybe other intriguing NEAs.

Orbit of asteroid Apophis (pink) in contrast to the orbit of Earth (blue), from the years 2028 to 2030. The yellow dot represents the sun. Apophis takes 323.6 days to orbit the sun. Earth takes 365.3 days. Thus this asteroid is a fairly frequent visitor to our region of space.

Image via Phoenix7777/ Wikimedia Commons.

This animation shows the distance between the Apophis asteroid and Earth at the time of the asteroid’s closest approach in 2029. The blue dots are manmade satellites orbiting our planet, and the pink represents the International Space Station.

Image via NASA/ JPL-Caltech.

LINKS VIDEOS

• https://youtu.be/eOTH5SBVU00

• https://youtu.be/8MFh27Y9DTw

{ https://www.space.com/ }

15-05-2024 om 01:40 geschreven door peter  

Computersimulaties tonen nieuw bewijs

{ https://www.nu.nl/ }

14-05-2024 om 20:30 geschreven door peter  

History Of Ceres’s Young Cold Traps

Ceres, the largest asteroid in our Solar System, harbors a dark secret: Extremely young ice deposits in permanently shadowed craters near its poles. If that sounds vaguely familiar, it’s because our Moon and planet Mercury also have such polar ice deposits, which have been studied for decades.

“For Ceres, the story started in 2016, when the Dawn spacecraft, which orbited around Ceres at the time, glimpsed into these permanently dark craters and saw bright ice deposits in some of them,” said Norbert Schorghofer, lead author of “History of Ceres’s Cold Traps Based on Refined Shape Models”that appears in The Planetary Science Journal. PSI scientists Robert Gaskell and John Weirich, and NASA Goddard Space Flight Center Scientist Erwan Mazarico, are coauthors on the paper.

“The discovery back in 2016 posed a riddle: Many craters in the polar regions of Ceres remain shadowed all year – which on Ceres lasts 4.6 Earth years – and therefore remain frigidly cold, but only a few of them harbor ice deposits,” Schorghofer said. “Soon, another discovery provided a clue why: The rotation axis of Ceres oscillates back and forth every 24,000 years due to tides from the Sun and Jupiter. When the axis tilt is high and the seasons strong, only a few craters remain shadowed all year, and these are the craters that contain bright ice deposits.”

To determine how large shadows were inside of craters thousands of years ago, scientists construct digital elevation maps and then perform ray-tracing calculations with them to theoretically reconstruct the shadows cast on the crater floors. The results are only as reliable as the digital shape models on which they are based. Keep in mind that the floors of these craters are always in shadow, so it is not easy to measure how deep they are.

The Dawn spacecraft had a very sensitive camera, which could discern features on the shadowed crater floors. Stereo images of sunlit regions are often used to construct digital elevation maps of sunlit regions, but making an elevation map of shadowed terrain is a challenge that had rarely been taken on. As part of the new study, PSI scientist Robert Gaskell developed a new technique to reconstruct heights even in the shadowed portions of a stereo pair of images. These improved elevation maps can then be used for ray-tracing to predict the extent of cold, permanently shadowed regions.

These more accurate maps yielded a surprising result: When Ceres reaches its maximum axis tilt, which last occurred about 14,000 years ago, no crater on Ceres remains perennially shadowed and any ice in them must have quickly sublimated into space. “That leaves only one plausible explanation: The ice deposits must have formed more recently than that. The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less. Considering that Ceres is well over 4 billion years old, that is a remarkably young age,” Schorghofer said.

Map of the north polar region of Ceres. The color areas are areas that are continuously shadowed over a Ceres year, and therefore very cold. The axis tilt (obliquity) of Ceres slowly changes over time and is currently 4 degrees, but ranged between 2 and 20 degrees over time. The color indicates the maximum obliquity at which a location is in shadow through an entire orbit.

Credit: Erwan Mazarico/GSFC.

“Ceres is an ice-rich object, but almost none of this ice is exposed on the surface. The aforementioned polar craters and a few small patches outside the polar regions are the only ice exposures. However, ice is ubiquitous at shallow depths – as discovered by PSI scientist Tom Prettyman and his team back in 2017 – so even a small dry impactor could vaporize some of that ice.” Schorghofer said. “A fragment of an asteroid may have collided with Ceres about 6,000 years ago, which created a temporary water atmosphere. Once a water atmosphere is generated, ice would condense in the cold polar craters, forming the bright deposits that we still see today. Alternatively, the ice deposits could have formed by avalanches of ice-rich material. This ice would then survive in only the cold shadowed craters. Either way, these events were very recent on an astronomical time scale.”

The study also looked into the possibility that other types of ices, other than water ice, might be trapped in these unusual craters on Ceres. On our Moon, portions of polar craters are so cold that even CO2 ice and a few other chemical species could last in them for billions of years. Ceres is farther from the Sun, so its polar craters could be expected to be even colder than the Moon’s.

Schorghofer calculated temperatures inside Ceres’s polar craters, something that had never been done before. The answer was surprising: although these craters are cold enough to retain water ice, they are too warm to retain other common types of ice. Two circumstances contribute to this. First, the axis tilt of Ceres, currently 4 degrees, is higher than the Moon’s 1.5 degree tilt, so more of the crater rims are sunlit and more light is scattered onto the crater floor. Second, Ceres simply has no perennially shadowed craters very near the north pole, unlike the Moon, where one crater sits almost exactly on the south pole. For these reasons, temperatures are not as low on Ceres than they are on parts of the lunar surface.

The study describes the new method used to reconstruct topography using stereo images of shadowed craters, provides a new map of perennially shadowed regions for the entire north polar region of Ceres, determines the extent of perennially shadowed regions inside polar craters with bright ice deposits, and estimates the temperatures for the interior of these craters. “Whatever the history of these ice deposits, it resulted from events not much older than human civilization,” Schorghofer said.

This work was funded by a grant from NASA’s Discover Data Analysis Program to PSI (80NSSC21K1033).

Images of two craters in the north polar region of Ceres captured by the Dawn spacecraft. The shadowed regions contain bright ice deposits, whereas sunlit regions appear saturated (white) in these contrast-stretched images. The superimposed color contours represent the extent of the area that is in shadow over the entire Cerean year for different values of the axis tilt. The current axis tilt is 4 degrees (yellow contour). The bright ice deposits must have accumulated at an axis tilt of 10 degrees or less (orange contour), which last occurred 6,000 years ago.

Credit: Norbert Schorghofer/PSI.

THE PLANETARY SCIENCE INSTITUTE:

The Planetary Science Institute is a private, nonprofit 501(c)(3) corporation dedicated to Solar System exploration. It is headquartered in Tucson, Arizona, where it was founded in 1972.

PSI scientists are involved in numerous NASA and international missions, the study of Mars and other planets, the Moon, asteroids, comets, interplanetary dust, impact physics, the origin of the Solar System, extra-solar planet formation, dynamics, the rise of life, and other areas of research. They conduct fieldwork on all continents around the world. They also are actively involved in science education and public outreach through school programs, children’s books, popular science books and art.

PSI scientists are based in 35 states and the District of Columbia.

{ https://astrobiology.com/ }

14-05-2024 om 20:21 geschreven door peter  

Planetary Scientists Create Map of Ceres’ Cold Traps

The dwarf planet Ceres hosts permanently shadowed areas in its polar regions, and these regions are an interesting analog to Mercury and the Moon. Ceres’ permanently shadowed regions were mapped by NASA’s Dawn spacecraft, and, thanks to scattered sunlight, bright deposits were discovered in a fraction of the permanently shadowed regions. To arrive at a clearer understanding of the nature of cold-trapped ice deposits on Ceres, researchers from the Planetary Science Institute and NASA’s Goddard Space Flight Center constructed improved shape models of permanently shadowed region-hosting craters.

Permanently shadowed regions in the north polar region of Ceres; the color indicates the maximum obliquity at which a location is in shadow through an entire orbit.

Image credit: Schorghofer et al., doi: 10.3847/PSJ/ad3639.

“For Ceres, the story started in 2016, when the Dawn spacecraft, which orbited around Ceres at the time, glimpsed into these permanently dark craters and saw bright ice deposits in some of them,” said lead author Dr. Norbert Schorghofer, a researcher at the Planetary Science Institute.

“The discovery back in 2016 posed a riddle: many craters in the polar regions of Ceres remain shadowed all year — which on Ceres lasts 4.6 Earth years — and therefore remain frigidly cold, but only a few of them harbor ice deposits.”

“Soon, another discovery provided a clue why: the rotation axis of Ceres oscillates back and forth every 24,000 years due to tides from the Sun and Jupiter.”

“When the axis tilt is high and the seasons strong, only a few craters remain shadowed all year, and these are the craters that contain bright ice deposits.”

To determine how large shadows were inside of craters thousands of years ago, scientists construct digital elevation maps and then perform ray-tracing calculations with them to theoretically reconstruct the shadows cast on the crater floors.

The results are only as reliable as the digital shape models on which they are based. Keep in mind that the floors of these craters are always in shadow, so it is not easy to measure how deep they are.

NASA’s Dawn spacecraft had a very sensitive camera, which could discern features on the shadowed crater floors.

Stereo images of sunlit regions are often used to construct digital elevation maps of sunlit regions, but making an elevation map of shadowed terrain is a challenge that had rarely been taken on.

As part of their study, the authors developed a new technique to reconstruct heights even in the shadowed portions of a stereo pair of images.

These improved elevation maps can then be used for ray-tracing to predict the extent of cold, permanently shadowed regions.

These more accurate maps yielded a surprising result: when Ceres reaches its maximum axis tilt, which last occurred about 14,000 years ago, no crater on Ceres remains perennially shadowed and any ice in them must have quickly sublimated into space.

“That leaves only one plausible explanation: the ice deposits must have formed more recently than that,” Dr. Schorghofer said.

“The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less.”

“Considering that Ceres is well over 4 billion years old, that is a remarkably young age.”

“Ceres is an ice-rich object, but almost none of this ice is exposed on the surface. The aforementioned polar craters and a few small patches outside the polar regions are the only ice exposures. However, ice is ubiquitous at shallow depths, so even a small dry impactor could vaporize some of that ice.”

“A fragment of an asteroid may have collided with Ceres about 6,000 years ago, which created a temporary water atmosphere.”

“Once a water atmosphere is generated, ice would condense in the cold polar craters, forming the bright deposits that we still see today.”

“Alternatively, the ice deposits could have formed by avalanches of ice-rich material. This ice would then survive in only the cold shadowed craters.”

“Either way, these events were very recent on an astronomical time scale.”

The researchers also looked into the possibility that other types of ices, other than water ice, might be trapped in these unusual craters on Ceres.

On our Moon, portions of polar craters are so cold that even carbon dioxide ice and a few other chemical species could last in them for billions of years.

Ceres is farther from the Sun, so its polar craters could be expected to be even colder than the Moon’s.

The scientists calculated temperatures inside Ceres’ polar craters, something that had never been done before.

The answer was surprising: although these craters are cold enough to retain water ice, they are too warm to retain other common types of ice. Two circumstances contribute to this.

First, the axis tilt of Ceres, currently 4 degrees, is higher than the Moon’s 1.5 degree tilt, so more of the crater rims are sunlit and more light is scattered onto the crater floor.

Second, Ceres simply has no perennially shadowed craters very near the north pole, unlike the Moon, where one crater sits almost exactly on the south pole.

For these reasons, temperatures are not as low on Ceres than they are on parts of the lunar surface.

“Whatever the history of the ice deposits, it resulted from events not much older than human civilization,” Dr. Schorghofer said.

• The findings appear in the Planetary Science Journal.
• Norbert Schorghofer et al. 2024. History of Ceres’s Cold Traps Based on Refined Shape Models. Planet. Sci. J 5 (99); doi: 10.3847/PSJ/ad3639

{ https://www.sci.news/ }

14-05-2024 om 18:42 geschreven door peter  

Ancient Lake On Mars Was Hospitable Enough To Support Life

The Gale Crater site once flowed with rivers ending in a lake

WRITTEN BY Amanda Doyle

SOURC Eastrobio.net

An up-close view of Mars’ rocky deposits by NASA’s Curiosity rover shows a changing climate in the planet’s ancient past that would have left the surface warm and humid enough to support liquid water — and possibly life. Evidence of an ancient lake points to the prospect of two unique habitats within its shores; the lower part of the lake was devoid of oxygen compared to an oxygen-rich upper half.

In a recent paper published in the journal Science, “Redox stratification of an ancient lake in Gale crater,” Stony Brook University geoscientist Joel Hurowitz and his colleagues used more than three years of data retrieved from the rover to paint a picture of ancient conditions at Gale Crater, the lowest point in a thousand kilometers. The site, a 150-mile kilometer crater formed during an impact around 3.8 billion years ago, once flowed with rivers ending in a lake. The sedimentary rocks laid down by these rivers and onto the lakebed tell the story of how the environment changed over time.

Curiosity landed on rocks known as the Bradbury group. The Murray formation consist of younger rocks at the base of Mount Sharp. The height is exaggerated in the diagram.

IMAGE CREDIT: NASA/JPL-CALTECH.

Curiosity landed on a group of sedimentary rocks known as the Bradbury group. The rover sampled a part of this group called the Sheepbed mudstones, as well as rocks from the Murray formation at the base of the 5-kilometer high peak at the center of the crater known as Mount Sharp. Both types of rocks were deposited in the ancient lake, but the Sheepbed rocks are older and occur lower in the stratigraphic layers of rocks. Comparing the two types of rocks can lead to interesting revelations about the paleoenvironment.

Rocks that form at the same time in the same area can nevertheless display differences in composition and other characteristics. These different groupings are known as “facies” and the Murray formation is split into two facies. One is comprised mainly of hematite and phyllosilicate, and given the name HP, while the other is the magnetite-silicate facies, known as MS.

“The two Murray facies were probably laid down at about the same time within different parts of the lake,” explained Hurowitz. “The former laid down in shallow water, and the latter in deeper water.”

The near-shore HP facies have thicker layers in the rocks compared to the thin layers of the deeper water MS facies. This difference in layer thickness is because the river flowing into the lake would have slowed down and dumped some of its sedimentary material at the lake shore. The flow would then have spread into the lake and dropped finer material into the deeper parts of the lake. .

The different mineralogy of the two facies was caused by the lake becoming separated into two layers. Ultraviolet (UV) radiation along with low levels of atmospheric oxygen penetrated the upper part of the lake and acted as oxidants on molecules in the water. These ions of iron (Fe²⁺) and manganese (Mn²⁺) were brought to the lake via seepage of groundwater through the lake floor.

An illustration showing how the lake in the crater might have looked.

IMAGE CREDIT: NASA/JPL-CALTECH/ESA/DLR/FU BERLIN/MSSS.

When the UV and oxygen interacted with these, they lost electrons, meaning that they had become “oxidized.” The oxidized iron and manganese precipitated into minerals — hematite and manganese oxide — that eventually made up the rocks sampled by Curiosity in the HP facies. However, the UV and oxygen didn’t reach all the way to the lake floor, so the iron and manganese wasn’t oxidized in the deeper part of the lake, and instead became the mineral known as magnetite, making up the MS facies.

The difference in oxidation of the two facies in the Murray formation due to differences in layers of the lake is known as redox stratification. Identifying redox stratification in the ancient lake shows that there were two completely different types of potential habitat available to any microbial life that might have been present.

The researchers also discovered that the Murray formation has a high concentration of salts, which provide clues relating to evaporation of the lake, and thus the end of the potential habitat. High salinity is a result of water evaporating and leaving salts behind. However, evaporation leaves other tell-tale signs such as desiccation cracks — similar to what you see when mud dries and cracks — and none of these signs appear in the Murray formation. This indicates that the evaporation occurred at a later period of time and that the salts seeped through layers overlying the Murray formation before becoming deposited in the Mursaid Hurowitz. “In fact, that’s exactly what the rover is doing as we speak at the area known as Vera Rubin Ridge.”

Once Curiosity examines these rocks, it will be able to confirm that the salts found in the Murray formation came from a later period of evaporation, and therefore no significant evaporation occurred during the time that the Murray formation was deposited, meaning the environment would have been stable enough to support possible life forms.

Another result of the research is evidence of climate change. The older Sheepbed formation shows very little evidence of chemical weathering coray rocks.

“Curiosity will definitely be able to examine the rocks higher up in the stratigraphy to determine if lake evaporation influenced the rocks deposited in it,” mpared to the Murray formation. The change to substantial chemical weathering in the younger rocks indicates that the climate likely changed from cold, arid conditions to a warm, wet one.

Thicker material (clastics) are close to the shore. Finer material is towards the deeper part of the lake. UV and O₂ oxidize iron and manganese, creating what is known as redox stratification. This is reflected in the mineralogy.

IMAGE CREDIT: HUROWITZ ET AL. (2017). SCIENCE..

“The timing of this climate shift is not something we can tell for sure because we haven’t seen the Sheepbed member and the Murray formation in contact with each other,” said Hurowitz. “If we had, then we might be able to tell if the change in their chemical and mineralogical properties were abrupt (indicating rapid climate change) or gradual. At best, what we can say is that the rocks that we examined were likely deposited over a timespan of tens of thousands of years to as much as around 10 million years.”

The cause of the climate change on Mars is still a matter of debate. If the climate changed in a short period of time, it could have been due to short-term variations or an asteroid impact. A slower change in climate could have been the result of changes in the obliquity cycle of the planet.

The climate change indicated in the rocks shows that the ancient Martian environment would have been warm and humid enough to sustain liquid water on the surface. The redox stratification of the lake as revealed by the different mineralogy in the Murray formation shows that there would have been two different environments within the lake itself. If microbial life was present on Mars at this time, the different potentially habitable niches could have encouraged diversity with anaerobic forms possibly living in the lower depths of the lake.

“I’m not sure that this was something we would have predicted if we hadn’t had the opportunity to examine

Curiosity Rover's Self Portrait at 'John Klein' Drilling Site.

IMAGE CREDIT: NASA/JPL-CALTECH/MSSS.

The Astrobiology Program was involved in all stages of the MSL mission. This included the development of instruments onboard the Curiosity rover, including Sample Analysis at Mars (SAM) and Chemistry & Mineralogy (CheMin).

The Astrobiology Program currently supports researchers involved in Curiosity mission operations and analysis of data from the rover.

{ https://astrobiology.nasa.gov/ }

14-05-2024 om 15:08 geschreven door peter  

I can remember when Perseverance was launched, travelled out into the Solar System and landed on Mars in February 2021.  In all the time since it arrived, having clocked up 1000 days of exploration, it has collected 23 samples from different geological areas within the Jezero Crater. The area was once home to an ancient lake and if there is anywhere on Mars to find evidence of ancient (fossilised) life, it is here. 

The date was 30 July 2020 when a gigantic Atlas V-541 rocket roared off the launchpad from Cape Canaveral in Florida. On board was the Perseverance rover, on its way to Mars. It arrived around 7 months later, entered the Martian atmosphere and successfully landed using a complex sequence of parachutes, retrorockets and for the first time, a sky crane to lower it from a hovering platform. Its chief purpose on Mars was to explore the geology, climate and atmospheric conditions as a precursor to human exploration. 

The landing site, the Jezero Crater, was chosen because previous orbital studies revealed clear evidence of an ancient lake that once filled the crater. It is thought that water is a key ingredient to the evolution of life so if there had been a body of water, then there is a greater chance of life evolving. Studying the rocks here is like taking a flick through the history books as it preserves signs of ancient life and also ancient environmental conditions. 

The crater had been formed, like the majority of other craters in the Solar System from some form of impact event. In the case of Jezero it was an asteroid impact around 4 billion years ago. On its arrival at the crater the floor was soon discovered to be made of igneous rock, formed from a huge underground chamber of magma and bought to the surface through volcanic activity. Since then, other types of rock from sand and mud were found providing evidence of the presence of water in Mars’ distant past. 

By the time Perseverance had hit the 1000 day anniversary of its exploration of the red planet it had collected the rock samples, safely packaged them up ready for collection and by and large, completed its exploration of the ancient lake bed. One sample in particular which has been called ‘Lefroy Bay’ has been found to contain fine grained silica. This material is commonly found on Earth and known to preserve fossils. Another of the samples contains phosphate which, on Earth is most definitely associated with biological processes. Both of these contain carbon which can be used to study the environmental conditions from when the rock formed. 

Jezero crater is a big place, 45 kilometres across so deciding on where to collect the samples was challenging. When a target site had been identified, Perseverance would first use its abrasion tool to wear away the surface and then use the onboard instruments such as PIXL, the Planetary Instrument for X-ray Lithochemistry. The instruments on board have the ability to detect both microscopic, fossil-like structures and also to identify chemical changes left behind by ancient microbes. Alas to date, whilst Perseverance has achieved an amazing amount, the detection of signs of life have alluded the rover. 

Source : 

• NASA’s Perseverance Rover Deciphers Ancient History of Martian Lake

{ https://www.universetoday.com/ }

14-05-2024 om 14:56 geschreven door peter  

The suit also has redundancy features, such as additional seals and pressure valves to help ensure the suit remains pressurized during EVAs. The new 3D-printed helmet incorporates a new visor that reduces glare and features a camera and a new Heads-Up Display (HUD) that monitors conditions inside the suit. These suits will make their debut during the first of three Polaris missions – Polaris Dawn – scheduled to take place this summer (at the earliest). This mission will be commanded by Isaacman and will see a Crew Dragon launched from Launch Complex 39A atop a Falcon 9 rocket. The crew will spend five days in orbit and attempt to reach the highest Earth orbit ever flown.

During their time in space, the Polaris Dawn crew will conduct the first commercial spacewalk (and the first EVA where four astronauts were in space simultaneously) and be the first to test the Starlink laser-based communication system in space. The crew will also conduct scientific research in collaboration with the Translational Research Institute for Space Health (TRISH), BioServe Space Technologies, Space Technologies Lab, Weill Cornell Medicine, the Johns Hopkins University Applied Physics Laboratory (JHUAPL), the Pacific Northwest National Laboratory, and the U.S. Air Force Academy.

These efforts are designed to advance our understanding of human health during long-duration spaceflights, with applications for health here on Earth. According to the company website, these research activities will include:

• Using ultrasound to monitor, detect, and quantify venous gas emboli (VGE), contributing to studies on human prevalence to decompression sickness;
• Gathering data on the radiation environment to better understand how space radiation affects human biological systems;
• Providing biological samples towards multi-omics analyses for a long-term Biobank; and
• Research related to Spaceflight Associated Neuro-Ocular Syndrome (SANS), which is a key risk to human health in long-duration spaceflight.

Polaris Dawn will be followed up by a second mission (Polaris II, the date of which is TBD) that will attempt to build upon these objectives. The third mission (Polaris III) will be the first human spaceflight involving the Starship and Super Heavy launch vehicle. But as is made clear in the company’s statement, the suits are intended to fulfill SpaceX’s long-term goals:

“While Polaris Dawn will be the first time the SpaceX EVA suit is used in low-Earth orbit, the suit’s ultimate destiny lies much farther from our home planet. Building a base on the Moon and a city on Mars will require the development of a scalable design for the millions of spacesuits required to help make life multiplanetary.”

Further Reading: 

• SpaceX, 
• Polaris Program

{ https://www.universetoday.com/ }

14-05-2024 om 14:43 geschreven door peter  

“Watches at this level are very rare,” the SWPC said in an advisory on Saturday.

Let’s take a look at the incredible views of our readers and friends, many shared on Universe Today’s Flickr page. Our lead image comes from Julien Looten, who took this photo at the cliffs of Étretat in northern France. Looten said, “These auroras began to be visible around 10:30 PM, even before nightfall… From then on, they were visible to the naked eye until dawn… Without interruption…”

{ https://www.universetoday.com/ }

14-05-2024 om 14:18 geschreven door peter  

Hundreds of alleged UFOs were spotted in the skies of southern Norway by a man trying to observe the Northern Lights phenomenon, but instead witnessed what he believes were 'dancing orbs'

By Ewan Gleadow - News Reporter

Possible UFO sightings were made in south Norway (file) 

(Image: Getty Images)

Regardless of what the lights represented, viewers were left stunned by one of "the coolest videos" they had ever seen. One user wrote the video was "super neat" and another said it was "beautiful".

Others questioned whether user CrayRazy had captured evidence of life from other planets. He wrote: "Saw this tonight in the south of Norway. At first I thought it was light beams from a festival but I live in a tiny city and that cloud is either over mountains, a lake or just a residential area.

"Really confused to what this could be. Any ideas?" Other users were left wondering if the lights in the sky were the recent sightings of aurora borealis, but one pointed out: "Aurora borealis is way higher up."

Another wrote: "UFOs are popping up for this storm. I saw one here". A third added: "I don't know, looks like a lot of shiny orbs. There seems to be a lot of UFO activity around this solar event!"

One said: "We are having a solar storm. The whole northern hemisphere is capable of seeing the aurora borealis." The original poster replied: "That's why I went outside but that doesn't look like the northern lights at all."

While a definitive answer was unavailable on what had caused the hundreds of tiny orbs to appear, some were adamant it was not UFOs and just a collection of northern lights sightings. But that's what they want you to think.

{ https://www.dailystar.co.uk/ }

12-05-2024 om 22:20 geschreven door peter  

There’s something poetic about humanity’s attempt to detect other civilizations somewhere in the Milky Way’s expanse. There’s also something futile about it. But we’re not going to stop. There’s little doubt about that.

One group of scientists thinks that we may already have detected technosignatures from a technological civilization’s Dyson Spheres, but the detection is hidden in our vast troves of astronomical data.

A Dyson Sphere is a hypothetical engineering project that only highly advanced civilizations could build. In this sense, ‘advance’ means the kind of almost unimaginable technological prowess that would allow a civilization to build a structure around an entire star. These Dyson Spheres would allow a civilization to harness all of a star’s energy.

A Civilization could only build something so massive and complex if they had reached Level II in the Kardashev Scale. Dyson Spheres could be a technosignature, and a team of researchers from Sweden, India, the UK, and the USA developed a way to search for Dyson Sphere technosignatures they’re calling Project Hephaistos. (Hephaistos was the Greek god of fire and metallurgy.)

They’re publishing their results in the Monthly Notices of the Royal Academy of Sciences. The research is titled “Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE.” The lead author is Matías Suazo, a PhD student in the Department of Physics and Astronomy at Uppsala University in Sweden. This is the second paper presenting Project Hephaistos. The first one is here.

“In this study, we present a comprehensive search for partial Dyson spheres by analyzing optical and
infrared observations from Gaia, 2MASS, and WISE,” the authors write. These are large-scale astronomical surveys designed for different purposes. Each one of them generated an enormous amount of data from individual stars. “This second paper examines the Gaia DR3, 2MASS, and WISE photometry of ~5 million sources to build a catalogue of potential Dyson spheres,” they explain.

Combing through all of that data is an arduous task. In this work, the team of researchers developed a special data pipeline to work its way through the combined data of all three surveys. They point out that they’re searching for partially-completed spheres, which would emit excess infrared radiation. “This structure would emit waste heat in the form of mid-infrared radiation that, in addition to the level of completion of the structure, would depend on its effective temperature,” Suazo and his colleagues write.

The problem is, they’re not the only objects to do so. Many natural objects do, too, like circumstellar dust rings and nebulae. Background galaxies can also emit excess infrared radiation and create false positives. It’s the pipeline’s job to filter them out. “A specialized pipeline has been developed to identify potential Dyson sphere candidates focusing on detecting sources that display anomalous infrared excesses that cannot be attributed to any known natural source of such radiation,” the researchers explain.

This flowchart shows what the pipeline looks like.

The pipeline is just the first step. The team subjects the list of candidates to further scrutiny based on factors like H-alpha emissions, optical variability, and astrometry.

368 sources survived the last cut. Of those, 328 were rejected as blends, 29 were rejected as irregulars, and 4 were rejected as nebulars. That left only 7 potential Dyson Spheres out of about 5 million initial objects, and the researchers are confident that those 7 are legitimate. “All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin,” they explain.

These are the seven strongest candidates, but the researchers know they’re still just candidates. There could be other reasons why the seven are emitting excess infrared. “The presence of warm debris disks surrounding our candidates remains a plausible explanation for the infrared excess of our sources,” they explain.

But their candidates seem to be M-type (red dwarf) stars, and debris disks around M-dwarfs are very rare. However, it gets complicated because some research suggests that debris disks around M-dwarfs form differently and present differently. One type of debris disk called Extreme Debris Disks (EDD) can explain some of the luminosity the team sees around their candidates. “But these sources have never been observed in connection with M dwarfs,” Suazo and his co-authors write.

That leaves the team with three questions: “Are our candidates strange young stars whose flux does not vary with time? Are these stars’ M-dwarf debris disks with an extreme fractional luminosity? Or something completely different?”

“After analyzing the optical/NIR/MIR photometry of ~5 x 10⁶ sources, we found 7 apparent M dwarfs exhibiting an infrared excess of unclear nature that is compatible with our Dyson sphere models,” the researchers write in their conclusion. There are natural explanations for the excess infrared coming from these 7, “But none of them clearly explains such a phenomenon in the candidates, especially given that all are M dwarfs.”

The researchers say that follow-up optical spectroscopy would help understand these 7 sources better. A better understanding of the H-alpha emissions is especially valuable since they can also come from young disks. “In particular, analyzing the spectral region around H-alpha can help us ultimately discard or verify the presence of young disks,” the researchers write.

“Additional analyses are definitely necessary to unveil the true nature of these sources,” they conclude.

{ https://www.universetoday.com/ }

12-05-2024 om 18:37 geschreven door peter  

Near-Collapse of Geomagnetic Field May Have Contributed to Diversification of Life on Earth

An ultra-weak geomagnetic field between 591 and 565 million years ago (Ediacaran period) coincided with a significant increase in the oxygen levels in the atmosphere and oceans, says a research team led by University of Rochester geoscientists.

Earth’s magnetic field was in a highly unusual state when macroscopic animals of the Ediacara Fauna diversified and thrived.

Image credit: NASA.

Between 600 and 540 million years ago, life on Earth consisted of soft-bodied organisms known as the Ediacaran Fauna, the earliest known complex multicellular animals.

The fossil record shows that these organisms significantly diversified in complexity and type between 575 and 565 million years ago

Previous research has suggested that this diversification is linked to a significant increase in atmospheric and oceanic oxygen levels that occurred over the same period.

However, it is not yet clear why this increase in oxygen occurred.

In the new study, University of Rochester’s Professor John Tarduno and colleagues analyzed the magnetic properties of 21 plagioclase crystals, a common mineral in Earth’s crust, which were extracted from a 591-million-year-old rock formation in Brazil.

Plagioclase crystals contain tiny magnetic minerals which preserve the intensity of the Earth’s magnetic field at the time they are formed.

An analysis of the crystals showed that, at their point of formation, the Earth’s magnetic field was the weakest ever recorded — some 30 times weaker than both the current magnetic field intensity, and that measured from similar crystals formed approximately two billion years ago.

The scientists combined their results with previous measurements to establish that the Earth’s magnetic field was at this weak level for at least 26 million years, from 591 to 565 million years ago.

This overlaps with the rise in oxygen, which occurred between 575 and 565 million years ago.

“The weakened magnetic field may have allowed more hydrogen to escape to space, resulting in a greater percentage of oxygen in Earth’s atmosphere and oceans, which may in turn have supported the diversification in the types and complexity of organisms,” the authors concluded.

• The findings were published in the journal Communications Earth & Environment.
• W. Huang et al. 2024. Near-collapse of the geomagnetic field may have contributed to atmospheric oxygenation and animal radiation in the Ediacaran period. Commun Earth Environ 5, 207; doi: 10.1038/s43247-024-01360-4

{ https://www.sci.news/ }

12-05-2024 om 00:49 geschreven door peter  

Krachtige zonne-explosies hebben een sterke impact op de aarde: wat zou er kunnen gebeuren?

 Door Janine

De krachtige uitbarstingen die op onze moederster exploderen, hebben een sterke impact op de aarde en lijken niet te stoppen. Dit is wat er gebeurt.

Wat zijn zonnevlammen?

SPACE WEATHER PREDICTION CENTER

Een zonnevlam, zo meldt NASA, is "een intense uitbarsting van straling door het vrijkomen van magnetische energie die gepaard gaat met zonnevlekken". Dit zijn, legt de Amerikaanse ruimtevaartorganisatie uit, de grootste explosieve gebeurtenissen in ons zonnestelsel. Ze manifesteren zich als heldere gebieden op de zon die enkele minuten tot enkele uren zichtbaar zijn.

Wat ons in staat stelt om ze te detecteren is het licht, dus de fotonen, die vrijkomen en die worden gecontroleerd door optisch licht en röntgenstraling. In zonnevlammen worden de zwaarste deeltjes versneld. De afgelopen dagen zijn zonnevlammen in volle actie: X1.6 vond plaats op 3 mei, gevolgd door andere krachtige fenomenen volgens het Space Weather Prediction Center van NOAA. Elk van deze fenomenen heeft een grote impact gehad op onze planeet.

De gevolgen van krachtige zonnevlammen op aarde

Een X1.3 en een X1.2 zonnevlam barstten op 5 mei los uit de actieve groep zonnevlekken AR 3663. In beide gevallen traden radio blackouts op op onze planeet, in Japan, Australië en grote delen van China, en de effecten zouden langer kunnen duren als coronale massa uitstoot, enorme wolken van zonneplasma doordrenkt met magnetische veldlijnen, geladen deeltjes naar de aarde zouden leiden.

Hierover zijn echter geen zekere gegevens bekend. Er zijn momenteel negen clusters zonnevlekken aanwezig aan de kant van de zon die naar onze planeet is gericht, die ongeveer 150 zonnevlekken omvatten. AR 3663 is op dit moment in ieder geval het meest actief en heeft sinds 30 april meerdere M-klasse en vier X-klasse vlammen uitgezonden, waarmee hij op de tweede plaats staat van de sterkste vlammen die onze ster kan produceren.

Maar wat zijn de voorspellingen van de wetenschappers en wat kunnen we verwachten? Volgens de voorspellers zullen er meer M-klasse vlammen zijn en mogelijk nog een of meer X-klasse vlammen voordat ze buiten de baan van de aarde draaien.

Keith Strong, een zonnefysicus, schreef in een bericht op X, voorheen Twitter: “Het gebied van zonnevlekken AR3663 produceerde een X4.5 vlam, de op twee na grootste sinds het begin van zonnecyclus 25 (4,3 jaar geleden)." Hij voegde eraan toe dat de vlam een sterke black-out veroorzaakte in een groot deel van Azië, Oost-Afrika en Oost-Europa. "Als het een coronale massa uitstoot produceerde, zal deze waarschijnlijk binnen een dag of twee de aarde raken."

Geomagnetische storm op komst? Er is iets positiefs aan

SDO | Solar Dynamics Observatory NASA

Zonnevlammen gaan soms gepaard met uitbarstingen die de aarde met een paar dagen vertraging kunnen bereiken, omdat plasma zich minder snel verplaatst dan licht. Op het moment dat de coronale massa uitstoot ons bereikt, ontstaat er echter een geomagnetische storm met aanzienlijke gevolgen voor de communicatie. Op het moment dat het de magnetosfeer van de planeet raakt, ontstaan er elektrische stromen die door elektriciteitsnetwerken kunnen reizen, stroomuitval kunnen veroorzaken en satellieten, radio- en navigatiesignalen kunnen beïnvloeden.

Maar er is ook een positief aspect: de wisselwerking tussen zonnedeeltjes, de magnetosfeer en de atmosfeer van de aarde leidt tot een opvallend poollicht boven de polen van de aarde, dat alleen 's nachts zichtbaar is, wanneer er geen zonlicht is. In elk geval zullen de volgende uitbarstingen kleine gevolgen hebben, omdat AR 3663 van de baan van de aarde af draait, maar de zon zit midden in haar activiteitscyclus, haar piek vindt om de elf jaar plaats en kan ons nog meer “verrassingen” bezorgen.

{ https://www.curioctopus.nl/ }

12-05-2024 om 00:31 geschreven door peter  

The sun appears to be angry; a massive coronal mass ejection unveils a striking image resembling a grimacing demonic face. Striking are the letters DV (DeVil?) standing out on the forehead of the figure. 

Obviously, the strange phenomenon captured by NASA's solar satellite SOLO EUI HRI 174 on 2024/05/11 is an ordinary natural occurrence triggered by the eruption of solar material but a fact is that a huge CME hit Earth's magnetic field on May 10th, leading up to the biggest geomagnetic storm in almost 20 year. 

And it is not yet over as forecasts predict additional coronal mass ejections to follow closely behind, prolonging the storm well into the weekend. Anticipation mounts for widespread auroras, promising captivating displays over regions like Europa and the United States. 

The storm has now reached level G5 which is the strongest level of geomagnetic storm, on a scale from G1 to G5. The solar storm could lead to disruption of satellite communication systems, low-frequency radio navigation systems such as GPS or even widespread power grid failures. 

This unique solar phenomenon emphasizes once more the importance of constant monitoring and readiness in response to solar disruptions in order to prevent another Carrington event which was the most intense geomagnetic storm in recorded history, peaking from 1–2 September 1859.

  

{ https://ufosightingshotspot.blogspot.com/ }

12-05-2024 om 00:18 geschreven door peter  

Cassini Observations Suggest Underground Ocean on Titan

Titan, the largest moon of Saturn, harbors an internal low-density ocean of water or ammonia, according to an analysis of archival data from NASA’s Cassini mission.

Representation of Cassini’s orbits used to calculate Titan’s gravity; the colored part of the orbits shows the distance from Cassini to Titan with the smallest distance in red; the cross-section of Titan shows the moon’s different layers with the ocean in blue; Saturn with rings and ring shadows can be seen in the background.

Image credit: Britt Griswold, NASA’s Goddard Space Flight Center.

“Liquid water is one of the prerequisites for the emergence of life,” said Dr. Sander Goossens from NASA’s Goddard Space Flight Center and colleagues.

“Water is rarely liquid on the surface of a planet, but a number of moons in our Solar System, such as Titan, contain underground oceans.”

“These probably formed long ago, which raises the question of why they are not yet frozen in the cold environment far from the Sun.”

“Our study supports the explanation that ammonia extended the life of the liquid ocean in Titan. In addition, it provides insight into Titan’s deeper layers.”

NASA’s Cassini mission explored Saturn and its icy moons for more than a decade.

Among its many instruments, Cassini carried a radio science subsystem that enabled Earth-based radiometric tracking of the spacecraft by the Deep Space Network.

These data were used to determine the gravity field and interior structure of several of Saturn’s moons as well as those of Saturn itself. Cassini data were also used to determine Titan’s tidal response.

“The Cassini space mission flew around Saturn between 2005 and 2017,” the researchers said.

“To precisely measure Titan’s gravity, the spacecraft was sent close to the moon several times.”

“Cassini had to skim past Titan at exactly the right time to properly map the change in gravity.”

“This is because Titan’s deformation is due to Saturn’s tidal force, which depends on the distance between Titan and Saturn.”

“By measuring at times when Titan is close and far away from Saturn, the difference in Titan’s deformation and thus its effect on gravity was maximum.”

From precise radar measurements, the scientists calculated Cassini’s velocity and then the change in gravity and Titan’s deformation associated with it.

They carefully examined the effect of tides on Titan at each location in the spacecraft’s orbit and concluded that the deformation is smaller than previously calculated.

Numerical simulations of the moon’s deformation for different internal structures show that the most likely scenario is that the ocean has a density similar to that of water with a small proportion of ammonia.

“An underground ocean can help transport organic material from a moon’s rock core to the surface,” the authors said.

“For Titan, it was assumed that a thick ice layer between the ocean and the core made this difficult.”

“Our analysis suggests that the ice layer is possibly thinner than previously thought, making exchange of material between rock and the ocean more plausible.”

“The organic molecules that this can produce are seen as important ingredients for the emergence of life.”

• The study was published in the journal Nature Astronomy.
• S. Goossens et al. A low-density ocean inside Titan inferred from Cassini data. Nat Astron, published online March 21, 2024; doi: 10.1038/s41550-024-02253-4

{ https://www.sci.news/ }

10-05-2024 om 23:20 geschreven door peter