The problems with AARO’s analysis weren’t overlooked by Mick West, arguably the most well-known UFO skeptic and the administrator of Metabunk, a website that crowdsources information West and other site contributors use to attempt to resolve UAP cases. In a posting on X following the release of AARO’s case analysis on the Eglin incident, West was quick to point out that the object in the photos obtained by the pilot bore little resemblance to images of a commercial lighting balloon used for comparison in AARO’s report.

“This Eglin UFO looks like a white sphere wearing a hat,” West wrote in his X posting that accompanied an image comparison he produced. “It shows a quite irregular ‘hat,’ which is not really consistent with the lighting balloon hypothesis.”

“I have never heard of ‘Earth Shine’ outside of the context of the Moon at night (or during a total eclipse),” West wrote in his posting at Metabunk. “But then the IC partner seems to think it’s direct illumination.”

“Their diagram is of little help,” West noted further, referring to an illustration in AARO’s report, which its authors use to explain why the lower portion of the object photographed by the pilot during the January 2023 incident might have appeared brighter than its upper portion, which West noted seems to be “at odds with the ‘earth shine’ theory.”

The Debrief reached out to West regarding his views on AARO’s analysis of the Eglin UAP case, as well as other issues that have arisen with official publications issued by the Pentagon’s UAP investigative office in recent weeks; most notably, AARO’s long-awaited “Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena (UAP) Volume I,” which it released earlier this year.

For West, the lighting balloon theory falls short of offering a definitive resolution for the case, as do several of AARO’s other recent assertions.

“The lighting balloon hypothesis always felt like something someone at AARO liked, but wasn’t really supported by much evidence,” West told The Debrief in an email.

In an interview earlier this year with CNN’s Peter Bergen, Dr. Sean Kirkpatrick, the former director of the Pentagon’s All-domain Anomaly Resolution Office, made vague references to instances where ‘Tic-Tac’-shaped balloons produced by a Florida-based company were believed to have escaped.

“One of my favorite things is there’s this company in Florida,” Kirkpatrick told Bergen during the interview. “They make these backyard lighting balloons. Some of them are round. Some of them are tic tac shaped, and they’re black on the top, and inside, they have lights, and they’re helium filled. And they’re strapped down in people’s backyards for backyard parties, and they get away. When we talked to the company, they’re like, ‘yeah, we lose ’em. And we sometimes find them again, but generally not.”

Dr. Sean Kirkpatrick, former Director of the All-domain Anomaly Resolution Office

(Credit: NASA).

“Well, you know, that’s a really weird-looking thing. Lit from the bottom, not light on the top, big tic-tac thing, flying around. Well, what is that? That kind of stuff is a flight hazard,” Kirkpatrick told Bergen at the time, although offering no additional details on any instances where such an object was believed to have been mistaken for a UAP.

West told The Debrief that Kirkpatrick’s remarks had initially sounded “almost as if he was trying to explain the Nimitz Tic-Tac, which would be rather a stretch.” However, with the release of the AARO’s report on the Eglin UAP case, it is now clear that this was the incident Kirkpatrick had been referring to at the time. West says that although some kind of lighter-than-air object cannot be dismissed, even AARO seemed uncertain whether this was a definitive conclusion, despite the report now being categorized as resolved.

“In the Eglin case, it can’t be ruled out, but it’s also not the only hypothesis [AARO] put forward,” West points out, noting that AARO’s recent report on the incident suggests that the Eglin UAP had been “very likely a lighter-than-air object, such as a large commercial lighting balloon,” although the report’s authors express that limited data on the case makes it difficult to rule out other potential explanations.

One of the primary issues critics have raised with the balloon hypothesis is that while it could potentially explain a single object, such as the one photographed by the military pilot during the January 2023 incident, this theory becomes more difficult when attempting to apply it to all four objects initially observed on radar.

Although West concedes this point, he also notes that AARO’s report never claimed that the lighting balloon hypothesis could account for all the objects, which the pilot initially judged to have been holding a diamond-shaped formation and potentially remaining stationary amidst 80 mph winds. If anything, AARO’s investigators seemingly ignored the presence of the additional three objects detected on radar, apart from a brief mention of them near the outset of their report.

West says that while the release of radar data from the Eglin incident might be helpful in making further determinations about the other objects the pilot detected, some caution would still be warranted.

“There’s a long history of conflating radar data with visual sightings,” West told The Debrief. “Unless it can clearly be demonstrated, we need to be open to the idea that what was seen on radar was not the same thing as seen visually (or on other sensors).” West cites similar instances where radar returns may have been unrelated to the primary objects captured on camera, including a case investigated by the Chilean Navy several years ago, which, after initially being touted as an unknown, was quickly revealed to have been a conventional aircraft.

“In the Chilean Navy case, much was made of the fact that there was no object on radar where the pilots thought the object was,” West says, “because it was 3x as far away.”

“So [the Eglin] the radar data could be something else, an unrelated glitch, or maybe even something related to the object (like a radar jammer/spoofer).”

While these possibilities exist, fundamentally, it remains unknown what the radar data might actually entail since, in addition to very little being said about it in AARO’s report, it presently remains inaccessible to the public.

“The problem here is that we don’t have the data,” West says. “We have the assessments of multiple experts that the sum total of the available data points towards something non-anomalous and lighter than air.”

“But unfortunately, we can’t check their work.”

• 

See Also

INCEPTION: HOW SCIENTISTS ARE TREATING REOCCURRING NIGHTMARES BY INJECTING SOUNDS INTO DREAMS

Asked if he felt that it would be helpful for independent analysts to review at least some of the additional data that was available to AARO investigators, West said that this might not only make AARO’s job easier, but it could potentially improve their analysis in significant ways.

“Ideally the data would be public, as the more eyes you have on something, the quicker issues and questions get resolved,” West told The Debrief. “AARO works with two partners, an IC (Intelligence Community) partner and an S&T (Science and Technology) partner. It’s not clear who they are, but they both seem to have reached similar conclusions. Oddly, neither seem to comment on the lighting balloon hypothesis, which suggests that it was internal to AARO, so three teams.”

One primary issue is that AARO, by virtue of its job within the government, often has to work with classified information related to various technologies and military operations. This limits its ability to properly communicate its findings and how much it can reveal about the experts and kinds of analysis from these three teams being employed in AARO’s investigations.

“The multi-domain and classified approach results in a fragmented report with very little visibility as to the workings of the three teams,” West says. “Adding more people, such as myself, or the broader public, would help iron out the inconsistencies and poorly communicated details.”

“There’s a risk it gets too messy, but I advocate for an approach called ‘curated crowdsourcing,’ which I described a few years ago,” West says, referencing an article in which he explains how crowdsourced information and analysis led to a reasonable explanation for the Chilean UAP footage within just a few days of its release.

Had the issues present in its recent report on the Eglin incident been the only instance where problems in AARO’s conclusions had been noted, some of the problems with its analysis might have been deemed innocuous. However, the release of the office’s proposed resolution for the 2023 Eglin UAP incident follows just weeks after the appearance of AARO’s Historical Record Report Volume I, which received a lackluster reception due to several factual inaccuracies it contained.

West shares some of those concerns about the mistakes in AARO’s recent publications, which he feels point to why independent analysis by civilian researchers is important.

“AARO should have had the report fact-checked and edited,” West told The Debrief. “They messed up.”

“They have multiple teams of highly paid people working with them, and they have done some good work. But putting out a report with lots of minor errors makes them look bad and casts doubt on their broader conclusions, such as the circular conversations leading up to the Kona Blue proposal and stories about crash retrievals.”

Unlike cases such as the Eglin UAP incident, which may involve reliance on some appropriately classified information, the public version of AARO’s historical report draws much of its contents from publicly accessible information. Additionally, an unclassified version of the report was planned for public release all along, as directed in legislation passed into law that required the completion and publication of the report.

Given that it was destined for public release anyhow, West told The Debrief that AARO might have benefited from having independent researchers offer feedback before the final version of the Historical Report was published.

“Since the report was going to be unclassified, there’s no reason why they could not utilize outside experts to review an embargoed version,” West says. “They could even contract with them, having them sign NDAs.

Fundamentally, West says that working more closely with independent researchers under such circumstances could have helped AARO produce a better, more accurate final report and may have reduced negative responses from many who, justifiably, viewed the report as lacking quality and factual merit.

“There’s no real downside,” West concluded, “and an error-free report is a much better way of conveying your research and conclusions than what they actually produced.”

• Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.

{ https://thedebrief.org/ }

09-05-2024 om 00:56 geschreven door peter  

New Study Explains Why Venus is Extremely Dry

Despite its Earth-like size and source material, Venus is extremely dry, indicating near-total water loss to space. Using computer simulations, planetary scientists from the University of Colorado, Boulder and the Laboratory for Atmospheric and Space Physics at the University of Arizona, Tucson found that hydrogen atoms in the planet’s atmosphere go whizzing into space through a process known as dissociative recombination — causing Venus to lose roughly twice as much water every day compared to previous estimates.

Venus today is dry thanks to water loss to space as atomic hydrogen.

Image credit: Aurore Simonnet / Laboratory for Atmospheric and Space Physics / University of Colorado at Boulder.

Despite being a close neighbor and being similar in size and source material to Earth, Venus is extremely dry.

Research has suggested that water from Venus’ once steam-dominant atmosphere was lost to space via a mechanism called hydrodynamic outflow.

However, this mechanism cannot remove all the water needed to explain current conditions, and other studied escape mechanisms are too slow to complete the process of water removal.

“Water is really important for life,” said Dr. Eryn Cangi, a researcher with the Laboratory for Atmospheric and Space Physics at the University of Arizona, Tucson.

“We need to understand the conditions that support liquid water in the universe, and that may have produced the very dry state of Venus today.”

“Venus is positively parched. If you took all the water on Earth and spread it over the planet like jam on toast, you’d get a liquid layer roughly 3 km (1.9 miles) deep.”

“If you did the same thing on Venus, where all the water is trapped in the air, you’d wind up with only 3 cm (1.2 inches), barely enough to get your toes wet.”

“Venus has 100,000 times less water than the Earth, even though it’s basically the same size and mass,” added Dr. Michael Chaffin, a researcher with the Laboratory for Atmospheric and Space Physics at the University of Arizona, Tucson.

The study authors propose a new explanation: a reaction called HCO+ dissociative recombination, which produces more escaping hydrogen than previously suggested processes.

HCO⁺ dissociative recombination would nearly double the rate of water loss to space from Venus and would resolve longstanding difficulties in explaining measured water abundances and isotope ratios on Venus.

Future Venus spacecraft missions need to measure HCO⁺ abundances to determine if HCO⁺ dissociative recombination is indeed the dominant mechanism for water loss.

“Our findings reveal new hints about why Venus, which probably once looked almost identical to Earth, is all but unrecognizable today,” Dr. Cangi said.

“We’re trying to figure out what little changes occurred on each planet to drive them into these vastly different states.”

• The results appear in the journal Nature.
• M.S. Chaffin et al. Venus water loss is dominated by HCO⁺ dissociative recombination. Nature, published online May 6, 2024; doi: 10.1038/s41586-024-07261-y

{ https://www.sci.news/ }

09-05-2024 om 00:34 geschreven door peter  

Ham, the Astrochimp Sent Into Space by NASA Before Alan Shepard and Neil Armstrong

On January 31, 1961, there was a special event in space history. A chimpanzee named Ham traveled into space, becoming the first of his kind to do so. Before famed astronauts like Alan Shepard and Neil Armstrong, there was Ham, a small chimpanzee, weighing only 37 pounds. Ham is remembered as both a hero and a creature who was put into a difficult situation during the space race.

Ham was part of a group of six chimps chosen for NASA’s Project Mercury. They were taken to Cape Canaveral in Florida, where they trained for three weeks in simulators designed to mimic the conditions of space. The purpose of sending Ham into space was to test if a spacecraft’s systems could keep a living creature safe and comfortable. This included making sure the life support systems worked during the short time of weightlessness in space.

Number 65 was a male chimpanzee, born in Africa in 1957. He was caught by trappers and taken to a bird farm in Florida. Then, in 1959, the U.S. Air Force bought him and took him to Holloman Air Force Base in New Mexico. There, he learned to be an astro-chimp, which is a chimpanzee trained for space missions. His handlers called him “Ham” because of where he was trained. Ham was one of 40 chimps picked for the space program.

Before sending humans to space, NASA wanted to see if they could do tasks there. They picked chimpanzees because they’re like humans in many ways. They wanted to see if chimps could do tasks in space that other animals couldn’t. In simple words, Ham was like a test subject to see if humans could survive a journey into space. According to NASA’s publication, This New Ocean: A History of Project Mercury, (“Ham Paves the Way” chapter):

Intelligent and normally docile, the chimpanzee is a primate of sufficient size and sapience to provide a reasonable facsimile of human behavior. Its average response time to a given physical stimulus is .7 of a second, compared with man’s average .5 second. Having the same organ placement and internal suspension as man, plus a long medical research background, the chimpanzee chosen to ride the Redstone and perform a lever-pulling chore throughout the mission should not only test out the life-support systems but prove that levers could be pulled during launch, weightlessness, and reentry.

The chimpanzees were trained to push buttons when they heard sounds or saw lights. If they did it right within five seconds, they got treats called banana pellets. If not, they felt a little shock on their feet. Scientists also made them experience what it’s like to feel strong forces and float in space, like the people training to go to space, called the “Mercury Seven.” They trained for almost two years.

The astrochimps were not trained to “pilot” space capsules. Instead, they were trained to do regular jobs during short space trips. They were also used as test subjects to understand the dangers of space travel, both physically and mentally. This helped scientists learn about the risks before sending humans, starting from the Mercury program and continuing into later space missions.

“According to one story, which strict scientists contend is apocryphal,” LIFE wrote, “a veterinarian gave a banana to a chimp before a rocket sled ride. As the animal peeled it, the ride started with a lurch and the monkey got the banana full in the face. The next time the chimp was offered a banana before a sled ride, he took it, peeled it, and smeared it over the veterinarian’s face.”

On January 31, 1961, a Mercury-Redstone launched from Cape Canaveral carrying the Ham over 400 miles down range in an arching trajectory that reached a peak of 158 miles above the Earth. Ham performed his lever-pulling tasks well in response to flashing lights. NASA used chimpanzees and other primates to test the Mercury capsule before launching the first American astronauts.

During the flight, his vital signs and various assigned tasks were closely monitored by computers back on Earth. At one point, the spacecraft lost some air because of a problem with a valve. But Ham was safe in his spacesuit. Ham’s journey in the spacecraft lasted for about 16 and a half minutes. He flew at around 5800 miles per hour and reached a height of 157 miles above the Earth. During part of the journey, he felt weightless for about 6 and a half minutes. Even with all the speed and strange feelings, Ham performed his tasks without any problem.

During the flight, they checked how Ham reacted to feeling weightless and speeding up by making him do tasks where he pulled levers. He had practiced doing these tasks before the flight. According to A Brief History of Animals in Space published by the NASA History Office, the flight did not go completely as planned:

The original flight plan called for an altitude of 115 miles and speeds ranging up to 4,400 mph. However, due to technical problems, the spacecraft carrying Ham reached an altitude of 157 miles and a speed of 5,857 mph and landed 422 miles downrange rather than the anticipated 290 miles… He experienced a total of 6.6 minutes of weightlessness during a 16.5-minute flight.

Read also:

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• Sanju Bhagat: Man Who Had a Human Parasite Living Inside Him For 36 Years

After the flight, when Ham’s capsule landed in the water, it was about 130 miles away from where it was supposed to be. The capsule started filling with water, but it took a few hours for a ship to come and rescue Ham. Amazingly, he was alive and seemed pretty calm, considering what he’d been through. His trainer described the moment he was recovered from his capsule following the project – “I have never seen such terror on a chimp’s face.” Biologist, Jane Goodall, would say his face showed “the most extreme fear.”

Later on, there was another moment that showed how scared Ham was. Some photographers wanted to take more pictures of him in his seat, but he refused to get back in. Even though people tried to make him, he wouldn’t do it.

After he flew into space, Ham lived alone for 20 years in the National Zoological Park in Washington D.C. Then, he moved to the North Carolina Zoo where he could be with other chimpanzees.

He died when he was only 26 years old on January 19, 1983. Some people wanted to make an exhibit of his stuffed body in a museum, but many disagreed. They thought it was disrespectful. An article in the Washington Post wrote, “Talk about death without dignity.” A letter in the Smithsonian Archives from a sophomore at West High School in Painted Post, New York, summed up the public mood: “By treating his body like that of a stupid beast, people will continue thinking of apes as stupid beasts, and not the intelligent, almost human animals they really are.”

Instead of being stuffed, Ham was cremated, and his ashes were buried with a plaque at the International Space Hall of Fame in Alamogordo, New Mexico. His bones are now shown at the National Museum of Health and Medicine.

{ https://www.howandwhys.com/ }

08-05-2024 om 21:52 geschreven door peter  

• Fragments of Planet Theia appear buried deep beneath Africa and the Pacific
• New evidence has emerged from deep within the moon via NASA's GRAIL craft
• READ MORE: Video spots 'space station' UFOs flying on dark side of the Moon

By MATTHEW PHELAN SENIOR SCIENCE REPORTER FOR DAILYMAIL.COM

A new study of metal ore deep inside the moon is offering fresh evidence that Earth's natural satellite was formed by an ancient planet crashing into Earth long ago.

This long-theorized interplanetary collision — which scientists believe occurred some 4.5 billion years ago — saw a Mars-sized planet named 'Theia' slice itself into hot lava fragments upon impact with the Earth.

While some of Theia's planetary remains appear to be buried as dense and massive 'blobs' deep underneath Africa and the Pacific Ocean's tectonic plates, scientists said evidence for where the rest of Theia went after this crash had remained elusive.

But now, new data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) spacecraft has found large telltale deposits of titanium-iron ore deep beneath the moon's surface, suggesting Theia's other remains did, in fact, form Earth's moon.

A new study of the moon is offering fresh evidence that Earth's natural satellite was formed by an ancient planet crashing into Earth. This long-theorized collision, some 4.5 billion years ago, saw a Mars-sized planet named 'Theia' slice into hot lava fragments upon impact with Earth

Under the moon's crust, in the region between the crust and the core known as the mantle, NASA's GRAIL craft detected two dense regions (pictured above) that match the titanium and iron 'ilmenite' deposits that would exist if the 'planet Theia' impact theory proves to be correct

Planetary geophysicist, Adrien Broquet of the German Aerospace Center in Berlin, described NASA's GRAIL findings as nothing short of 'mesmerizing.'

His team's new paper, published this April in Nature Geoscience, focused on 'gravity anomalies' deep under the moon's surface: dense, heavy pockets of matter identified by the GRAIL spacecraft's sensors.

'Analyzing these variations in the moon's gravity field allowed us to peek under the moon's surface and see what lies beneath,' Broquet said.

READ MORE: 

• Earth may have lost 60 percent of its atmosphere in the massive collision that formed the Moon 4.5 billion years ago

New research led by Durham University involved more than 300 supercomputer simulations designed to show the consequence of a huge collision on the planet. 

Under the moon's crust, in the region between the crust and the core known as the mantle, the GRAIL craft detected two dense regions that match the titanium and iron 'ilmenite' deposits that would exist if the Theia impact theory was correct.

After Theia's likely collision with Earth, and after fragments of this lost planet became buried deep below Earth's crust, molten lava pools of heavy titanium and iron on the moon's surface began to sink deeper towards its core, pushing lighter rock up.

'Our moon literally turned itself inside out,' said Broquet's co-author, Jeff Andrews-Hanna, a geophysicist at the University of Arizona's Lunar and Planetary Laboratory.

Computer models by their colleague, Nan Zhang at Peking University in Beijing, offered the original framework for their theory that titanium-rich material would exist deep within the moon as a result of the moon's origins as chunks of planet Theia. 

'When we saw those model predictions,' Andrews-Hanna said, 'it was like a lightbulb went on.' 

'We see the exact same pattern when we look at subtle variations in the moon's gravity field,' he said, 'revealing a network of dense material lurking below the crust.' 

Back on Earth, two similarly dense and unusual regions at the base of our planet's mantle — known as Large Low Velocity Provinces (LLVPs) — have also lent credence to the theory that an interplanetary 'Theia' collision created our moon.

One LLVP is located beneath the African tectonic plate and the other under the Pacific tectonic plate, as measured by seismic equipment similar to that used to detect earthquakes.

Their existence was established when geologists found that seismic waves slowed dramatically at a depth of 1,800 miles (2,900 km) in the two regions, which differed to other parts of the Earth.

Scientists have found new evidence our that the moon was created during a giant impact between Earth and a Mars-sized protoplanet called Theia 4.5 billion years ago. This also buried relics of Theia deep within Earth's mantle (depicted following the collision)

After running a series of simulations, Professor Hongping Deng discovered that following the moon-forming impact a significant amount of Theian mantle material – around two percent of Earth's mass – entered the lower mantle (shown in orange in the artist's impression above)

Scientists believe the material in these LLVPs is between 2 and 3.5 percent denser than the Earth's surrounding mantle. 

Last year, Researchers led by the California Institute of Technology came up with the idea that these LLVPs could have evolved from a small amount of Theian material that entered the ancient Earth's lower mantle. 

To back this up, they asked Professor Hongping Deng, of the Shanghai Astronomical Observatory, to explore this idea with the help of his pioneering methods in computational fluid dynamics.

After running a series of simulations, Professor Deng discovered that following the moon-forming impact a significant amount of 'Theian' material — around two percent of Earth's mass — would have entered the lower mantle of the ancient planet Earth. 

'Through precise analysis of a wider range of rock samples, combined with more refined giant impact models and Earth evolution models, we can infer the material composition and orbital dynamics of the primordial Earth, "Gaia," and "Theia,"' said Deng's co-author Qian Yuan, a CalTech geophysicist who also worked on this project.

Deng and Yuan's team published their study in the journal Nature late last year.

Broquet said he hopes future NASA missions to the moon, like those scheduled for the Artemis program, will be able to take similar seismic measurements: first-of-their-kind seismic data from the moon to better corroborate the Theia collision theory.

'Future missions, such as with a seismic network, would allow a better investigation of the geometry of these structures,' the researcher said. 

THEIA: AN ANCIENT PROTO-PLANET THAT MAY HAVE MERGED WITH THE YOUNG EARTH TO FORM THE MOOON

About 4.45 billion years ago, 150 million years after the solar system formed, Earth was hit by a Mars-size object called Theia.

The collision created the moon, but debate has raged exactly what happened during this event - and a mystery has persisted on why the moon and Earth are so similar in their composition.

The impact of Theia with Earth was so violent, the resulting debris cloud mixed thoroughly before settling down and forming the moon.

This cloud would have been composed of some Earth material, explaining the similarity between Earth and the moon, and other material.

The colliding body is sometimes called Theia, after the mythical Greek Titan who was the mother of Selene, the goddess of the Moon.

But one mystery has persisted, revealed by rocks the Apollo astronauts brought back from the moon - why are the moon and Earth so similar in their composition?

Several different theories have emerged over the years to explain the similar fingerprints of Earth and the moon.

Perhaps the impact created a huge cloud of debris that mixed thoroughly with the Earth and then later condensed to form the moon.

Or Theia could have, coincidentally, been isotopically similar to young Earth.

A third possibility is that the moon formed from Earthen materials, rather than from Theia, although this would have been a very unusual type of impact.

{ https://www.dailymail.co.uk/ }

08-05-2024 om 01:03 geschreven door peter  

The Sun is increasing its intensity on schedule, continuing its approach to solar maximum. In just over a 24-hour period on May 5 and May 6, 2024, the Sun released three X-class solar flares measuring at X1.3, X1.2, and X4.5. Solar flares can impact radio communications and electric power grids here on Earth, and they also pose a risk to spacecraft and astronauts in space.

NASA released an animation that shows the solar flares blasting off the surface of the rotating Sun, below.

Predicting when solar maximum will occur is not easy and the timing of it can only be confirmed after it happens. But NOAA’s Space Weather Prediction Center (SWPC) currently estimates that solar maximum will likely occur between May 2024 and early 2026. The Sun goes through a cycle of high and low activity approximately every 11 years, driven by the Sun’s magnetic field and indicated by the frequency and intensity of sunspots and other activity on the surface. The SWPC has been working hard to have a better handle on predicting solar cycles and activity. Find out more about that here.  

Solar flares are explosions on the Sun that release powerful bursts of energy and radiation coming from the magnetic energy associated with the sunspots. The more sunspots, the greater potential for flares.

Flares are classified based on a system similar to the Richter scale for earthquakes, which divides solar flares according to their strength. X-class is the most intense category of flares, while the smallest ones are A-class, followed by B, C, M and then X. Each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. The number that follows the letter provides more information about its strength. The higher the number, the stronger the flare.

Flares are our solar system’s largest explosive events. They are seen as bright areas on the Sun and can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, occurring in various wavelengths.

Sometimes, but not always, solar flares can be accompanied by a coronal mass ejection (CME), where giant clouds of particles from the Sun are hurled out into space.  If we’re lucky, these charged particles will provide a stunning show of auroras here on Earth while not impacting power grids or satellites.

Thankfully, missions like the Solar Dynamics Observatory, Solar Orbiter, the Parker Solar Probe are providing amazing views and new details about the Sun, helping astronomers to learn more about the dynamic ball of gas that powers our entire Solar System.

{ https://www.universetoday.com/ }

07-05-2024 om 21:29 geschreven door peter  

The names Brown and Batygin, both Caltech astronomers, come up often in regard to P9. Now, they’ve published another paper along with colleagues Alessandro Morbidelli and David Nesvorny, presenting more evidence supporting P9.

It’s titled “Generation of Low-Inclination, Neptune-Crossing TNOs by Planet Nine.” It’s published in The Astrophysical Journal Letters.

“The solar system’s distant reaches exhibit a wealth of anomalous dynamical structure, hinting at the presence of a yet-undetected, massive trans-Neptunian body—Planet Nine (P9),” the authors write. “Previous analyses have shown how orbital evolution induced by this object can explain the origins of a broad assortment of exotic orbits.”

To dig deeper into the issue, Batygin, Brown, Morbidelli, and Nesvorny examined Trans-Neptunian Objects (TNOs) with more conventional orbits. They carried out N-body simulations of these objects that included everything from the tug of giant planets and the Galactic Tide to passing stars.

29 objects in the Minor Planet Database have well-characterized orbits with a > 100 au, inclinations < 40°, and q (perihelia) < 30 au. Of those 29, 17 have well-quantified orbits. The researchers focused their simulations on these 17.

The researchers’ goal was to analyze these objects’ origins and determine if they could be used as a probe for P9. To accomplish this, they conducted two separate sets of simulations. One set with P9 in the Solar System and one set without.

The simulations began at t=300 million years, meaning 300 million years into the Solar System’s existence. At that time, “intrinsic dynamical evolution in the outer solar system is still in its infancy,” the authors explain, while enough time has passed for the Solar System’s birth cluster of stars to disperse and for the giant planets to have largely concluded their migrations. They ended up with about 2000 objects, or particles, in the simulation with perihelia greater than 30 au and semimajor axes between 100 and 5000 au. This ruled out all Neptune-crossing objects from the simulation’s starting conditions. “Importantly, this choice of initial conditions is inherently linked with the assumed orbit of P9,” they point out.

The figure below shows the evolution of some of the 2,000 objects in the simulations.

These are interesting results, but the researchers point out that they in no way prove the existence of P9. These orbits could be generated by other things like the Galactic Tide. In their next step, they examined their perihelion distribution.

“Accounting for observational biases, our results reveal that the orbital architecture of this group of objects aligns closely with the predictions of the P9-inclusive model,” the authors write. “In stark contrast, the P9-free scenario is statistically rejected at a ~5? confidence level.”

The authors point out that something other than P9 could be causing the orbital unruliness. The star was born in a cluster, and cluster dynamics could’ve set these objects on their unusual orbits before the cluster dispersed. A number of Earth-mass rogue planets could also be responsible, influencing the outer Solar System’s architecture for a few hundred million years before being removed somehow.

However, the authors chose their 17 TNOs for a reason. “Due to their low inclinations and perihelia, these objects experience rapid orbital chaos and have short dynamical lifetimes,” the authors write. That means that whatever is driving these objects into these orbits is ongoing and not a relic from the past.

An important result of this work is that it results in falsifiable predictions. And we may not have to wait long for the results to be tested. “Excitingly, the dynamics described here, along with all other lines of evidence for P9, will soon face a rigorous test with the operational commencement of the VRO (Vera Rubin Observatory),” the authors write.

If P9 is real, what is it? It could be the core of a giant planet ejected during the Solar System’s early days. It could be a rogue planet that drifted through interstellar space until being caught up in our Solar System’s gravitational milieu. Or it could be a planet that formed on a distant orbit, and a passing star shepherded it into its eccentric orbit. If astronomers can confirm P9’s existence, the next question will be, ‘what is it?’

If you’re interested at all in how science operates, the case of P9 is very instructive. Eureka moments are few and far between in modern astronomy. Evidence mounts incrementally, accompanied by discussion and counterpoint. Objections are raised and inconsistencies pointed out, then methods are refined and thinking advances. What began as one over-arching question is broken down into smaller, more easily-answered ones.

But the big question dominates for now and likely will for a while longer: Is there a Planet Nine?

Stay tuned

{ https://www.universetoday.com/ }

07-05-2024 om 21:18 geschreven door peter  

It’s that time again. NIAC (NASA Innovative Advanced Concepts) has announced six concepts that will receive funding and proceed to the second phase of development. This is always an interesting look at the technologies and missions that could come to fruition in the future.

The six chosen ones will each receive $600,000 in funding to pursue the ideas for the next two years. NASA expects each team to use the two years to address both technical and budgetary hurdles for their concepts. When this second phase comes to an end, some of the concepts could advance to the third stage.

“These diverse, science fiction-like concepts represent a fantastic class of Phase II studies,” said John Nelson, NIAC program executive at NASA Headquarters in Washington. “Our NIAC fellows never cease to amaze and inspire, and this class definitely gives NASA a lot to think about in terms of what’s possible in the future.”

Here they are.

1. Fluidic Telescope (FLUTE): Enabling the Next Generation of Large Space Observatories

Telescopes are built around mirrors and lenses, whether they’re ground-based or space-based. The JWST’s large mirror is 6.5 meters in diameter but had to be folded up to fit inside the rocket that launched it and then unfolded in space. That’s a tricky engineering feat. Engineers are building larger and larger ground-based telescopes, too, and they’re equally tricky to design and build. Could FLUTE change this?

FLUTE envisions lenses made of fluid, and the FLUTE team’s concept describes a space telescope with a primary mirror 50 meters (164 ft.) in diameter. Creating glass lenses for a telescope this large isn’t realistic. “Using current technologies, scaling up space telescopes to apertures larger than approximately 33 feet (10 meters) in diameter does not appear economically viable,” the FLUTE website states.

But in the microgravity of space, fluids behave in an intriguing way. Surface tension holds liquids together at their surfaces. We can see this on Earth, where some insects use surface tension to glide along the surfaces of ponds and other bodies of water. Also, on Earth, surface tension holds small drops of water together. But in space, away from Earth’s dominating gravity, surface tension is much more effective. There, water maintains the most energy efficient shape there is: a sphere.

Another force governs water: adhesion. Adhesion causes liquids to cling to surfaces. In the microgravity of space, adhesion can bind liquid to a circular, ring-like frame. Then, due to surface tension, the liquid will naturally adopt a spherical shape. If the liquid can be made to bulge inward rather than outward, and if the liquid is reflective enough, it creates a telescope mirror.

The FLUTE team would like to make optical components in space. The liquid would stay in the liquid state and form an extremely smooth light-collecting surface. As a bonus, FLUTE would also self-repair after any micrometeorite strike.

The FLUTE study is led by Edward Balaban from NASA’s Ames Research Center in California’s Silicon Valley. The FLUTE team has already done some tests on the ISS and on zero-g flights.

2. Pulsed Plasma Rocket (PPR): Shielded, Fast Transits for Humans to Mars

It takes too long to get to Mars. It’s a six-month journey each way, plus time spent on the surface. All that time in microgravity, exposure to radiation, and other challenges make the trip very difficult for astronauts. PPR aims to fix that.

PPR isn’t a launch vehicle for escaping Earth’s gravity well. It would be launched on a heavy lift vehicle like SLS and then sent on its way.

PPR was originally derived from the Pulsed Fission Fusion concept. But it’s more affordable, and also smaller and simpler. PPR might generate 100,000 N of thrust with a specific impulse (Isp) of 5,000 seconds. Those are good numbers. PPR could reduce the travel time to Mars to two months.

It has other benefits as well. It could propel larger spacecraft to Mars on trips longer than two months, carrying more cargo and also provide heavier shielding against cosmic rays. “The PPR enables a whole new era in space exploration,” the team writes.

PPR is basically a fusion system ignited by fission. It’s similar to a thermonuclear weapon. But rather than a run-away explosion, the combined energy is directed through a magnetic nozzle to produce thrust.

In phase two, the PPR team intends to optimize the engine design to produce more specific impulse, perform proof-of-concept experiments for major components, and design a shielded ship for human missions to Mars.

This study is led by Brianna Clements with Howe Industries in Scottsdale, Arizona.

3. The Great Observatory for Long Wavelengths (GO-LoW)

One of modern astronomy’s last frontiers is the low-frequency radio sky. Earth’s ionosphere blocks our ground-based telescopes from seeing it. And space-based telescopes can’t see it either. It’s because the wavelengths are so long, in the meter to the kilometre scale. Only extremely massive telescopes could see these waves clearly.

GO-LoW is a potential solution. It’s a space-based array of thousands of identical Small-Sats arranged as an interferometer. It would sit at an Earth-Sun Lagrange point and observe exoplanet and stellar magnetic fields. Exoplanet magnetic fields emit radio waves between 100 kHz and 15 MHz. The GO-LoW team says their interferometer could perform the first survey of exoplanetary magnetic fields within 5 parsecs (16 light years.) Magnetic fields tell scientists a lot about an exoplanet, its evolution, and its processes.

While there’s no doubt that large telescopes like the JWST are powerful and effective, they’re extremely complex and expensive. And if something goes wrong with a critical component, the mission could end.

GO-LoW takes a different approach. By using thousands of individual satellites, the system is more resilient. GO-LoW would have a hybrid constellation. Some of the satellites would be smaller and simpler satellites called “listener nodes” (LN,) while a smaller number of them would be “communication and computation” nodes (CCNs). They would collect data from the LNs, process it, and beam it back to Earth.

The GO-LoW says it would only take a few heavy launches to place an entire 100,000 satellite constellation in space.

The technology for the SmallSats already exists. The challenge the GO-LoW team will address with their phase two funding is developing a system that will harness everything together effectively. “The coordination of all these physical elements, data products, and communications systems is novel and challenging, especially at scale,” they write.

GO-LoW is led by Mary Knapp with MIT in Cambridge, Massachusetts.

4. Radioisotope Thermoradiative Cell Power Generator

It’s sort of like solar power in reverse.

The RTCPG is a power source for spacecraft visiting the outer planets. They promise smaller, more efficient power generation for smaller science and exploration missions that can’t carry a solar power system or nuclear power system. Both those systems are bulky, and solar power is limited the further away from the sun a spacecraft goes.

The thermoradiative cell (TRC) uses radioisotopes to create heat as an MMRTG does. But the TRC uses the heat to generate infrared light which generates electricity. In initial testing, the system generated 4.5 times more power from the same amount of PU-238.

Much of phase two’s work will involve materials. “Metal-semiconductor contacts capable of surviving the required elevated temperatures will be investigated,” the team explains. The team developed a special cryostat testing apparatus in phase one.

“Building on our results from Phase I, we believe there is much more potential to unlock here,” the team writes.

This power generation concept study is from Stephen Polly at the Rochester Institute of Technology in New York.

5. FLOAT: Flexible Levitation on a Track

What if Artemis is enormously successful? How will astronauts move their equipment around the lunar surface efficiently?

FLOAT would provide autonomous transportation for payloads on the Moon. “A durable, long-life robotic transport system will be critical to the daily operations of a sustainable lunar base in the 2030’s,” the FLOAT team writes.

The heart of FLOAT is a three-layer flexible track that’s unrolled into position without major construction. It consists of three layers: a graphite layer, a flex-circuit layer, and a solar panel layer.

The graphite layer allows robots to use diamagnetic levitation to float over the track. The flex-circuit layer supplies the thrust that moves them, and the thin-film solar panel layer generates electricity for a lunar base when it’s in sunlight.

The system can be used to move regolith around for in-situ resource utilization and to transport payloads around a lunar base, for example, from landing zones to habitats.

“Individual FLOAT robots will be able to transport payloads of varying shape/size (>30 kg/m^2) at useful speeds (>0.5m/s), and a large-scale FLOAT system will be capable of moving up to 100,000s kg of regolith/payload multiple kilometres per day,” the FLOAT team explains.

With their phase two funding, the FLOAT team intends to design, build, and test scaled-down versions of FLOAT robots and track. Then, they’ll test their system in a lunar analog testbed. They’ll also test environmental effects on the system and how they alter the system’s performance and longevity.

Ethan Schaler leads FLOAT at NASA’s Jet Propulsion Laboratory in Southern California.

6. SCOPE: ScienceCraft for Outer Planet Exploration

Some of the most intriguing planets and moons in the Solar System are well beyond Jupiter. But exploring them is challenging. Extremely long travel times, restrictive mission windows, and large expenses limit our exploration. But SCOPE aims to address these limitations.

Typically, a spacecraft carries a propulsion and power system along with its instruments and communication systems. NASA’s Juno mission to Jupiter, for example, carries a chemical rocket engine for propulsion, 50 square meters of solar panels, and 10 science instruments. The solar panels alone weigh 340 kg (750 lbs.) Juno is powerful, produces a wide variety of quality science data, and is expensive.

ScienceCraft takes a different approach. It combines a single science instrument and spacecraft into one monolithic structure. It’s basically a solar sail with a built-in spectrometer. They’re aiming their design at the Neptune-Triton system.

“By printing an ultra-lightweight quantum dot-based spectrometer, developed by the PI Sultana, directly on the solar sail, we create a breakthrough spacecraft architecture allowing an unprecedented parallelism and throughput of data collection and rapid travel across the solar system,” the ScienceCraft team writes.

Instead of merely providing the propulsion, the sail doubles as the spacecraft’s science instrument. The small mass means that ScienceCraft could be carried into orbit as a secondary payload. The team says they’ll use phase two to identify and develop key technologies for the spacecraft and to further mature the mission concept. They say that because of the low cost and simplicity, they could be ready by 2045.

“By leveraging these benefits, we propose a mission concept to Triton, a unique planetary body in our solar system, within the short window that closes around 2045 to answer compelling science questions about Triton’s atmosphere, ionosphere, plumes and internal structure,” the ScienceCraft team explains.

ScienceCraft is led by NASA’s Mahmooda Sultana at the agency’s Goddard Space Flight Center in Greenbelt, Maryland.

{ https://www.universetoday.com/ }

07-05-2024 om 21:01 geschreven door peter  

There’s also the Swedish Negative Ions on Lunar Surface (NILS), an instrument that will detect and measure negative ions reflected by the lunar surface. Lastly, there’s the Pakistani ICUBE-Q CubeSat developed by the Institute of Space Technology (IST) and Shanghai Jiao Tong University (SJTU), which will take images of the lunar surface using two optical cameras and measure the Moon’s magnetic field. The data these instruments provide will reveal new information about the lunar environment that will inform plans for long-duration missions on the surface.

By 2026, the Chang’e-6 mission will be joined by Chang’e-7, including an orbiter, lander, rover, and a mini-hopping probe. The data provided by the program will assist China’s plans to land taikonauts around the lunar south pole by 2030, followed by the completion of the ILRS by 2035.

Further Reading: 

• CGTN

{ https://www.universetoday.com }

06-05-2024 om 22:24 geschreven door peter  

Here are the 7 best places to search for life in the solar system

by Andy Tomaswick, Universe Today

If humanity is ever going to find life on another planet in the solar system, it's probably best to know where to look. Plenty of scientists have spent many, many hours pondering precisely that question, and plenty have come up with justifications for backing a particular place in the solar system as the most likely to hold the potential for harboring life as we know it. Thanks to a team led by Dimitra Atri of NYU Abu Dhabi, we now have a methodology by which to rank them.

The methodology, published in a recent preprint paper on arXiv, is focused on a new variable—the Microbial Habitability Index (MHI). MHI is intended to measure how habitable a specific environment is for the various types of extremophiles found in extreme places here on Earth.

As with many great engineering challenges, the authors broke down the process of developing an effective MHI into a series of steps. First, they defined a series of six environmental variables that can affect the habitability of a particular environment for life. They then defined six types of environments that are generally thought to exist on many potentially habitable worlds. They then picked seven of those habitable worlds and collected all the data they could on the environmental factors for each type of environment on each potentially habitable world.

With that data, they compared the values found in those environments to the values that extremophiles can live in. The results aren't particularly surprising to anyone interested in solar system astrobiology, but quantifiable data back them up. It seems Europa, Mars, and Enceladus are the most likely candidates to find bacterial life.

To get to this conclusion required a lot of data collection and quantification, though. First, the team had to define what environmental factors were the most important for the potential habitability of life. They settled on six: temperature, pressure, UV radiation, Ionizing radiation, pH, and salinity. Life can only survive in a narrow band of these values, and they serve as a reasonable basis for starting to think about what environmental features are necessary to support life.

Luckily, scientists have also collected data on life forms that thrive in the extremes of each of those six factors. From Serpentinomonas sp. B1 that can survive in pHs as high as 12.5 to Thermococcus piezophilus CDGS that can withstand pressures of up to 125 MPa, Earth's extremophiles give a good indication of what life might be able to contend with on other planets. Utilizing the highs and lows of the factors they selected, the scientists were able to determine the bounds an environment would have to conform to support life as we know it.

Those environments were the next things the scientists turned their attention to. They came up with a list of six potentially biologically interesting environments that were found to harbor life on Earth and then defined the ranges of the six environmental factors in each of those environments on Earth. Included in the list were: Icy Poles, Surface Continent, Subsurface Continent, Subsurface Ices, Ambient Ocean, Deep Ocean Floor, and Hydrothermal Vents. Each of those environments on Earth harbors life in some form, so the authors posit they could do so on some other world as well.

To find the most habitable places in the solar system, the researchers went down the list of worlds in the solar system. They eliminated most based on an outlier in one or more of the environmental factors they had defined as essential to biological life. At the end of their eliminations, though, they were left with seven potentially habitable worlds: Mars, Europa, Enceladus, Titan, Ganymede, Callisto, and (somewhat surprisingly) Pluto.

After getting all the selections out of the way, the authors got to the data collection phase. They collected data as much data as they could find about every time of environment that had been found on each of the worlds. Not every world is blessed with each of those environments, though. For example, Mars has no hydrothermal vents that we know of. However, that doesn't mean that other environments on the Red Planet wouldn't make a good candidate for astrobiology.

After collecting what data they could, they compared that data to the range defined by whether a microbe could withstand the ranges of environmental factors they would be subjected to at a given environment and, in so doing, came up with the MHI. The best way to summarize the outcome of their calculations is through a table showing the number of environmental factors that fall within the habitable range of extremophiles for each of the six environments selected as part of the study. The table is reproduced below.

The denominator in each of the entries signifies how many of the environmental factors the researchers could find data on. If the number is less than six, the researchers could not find data on one or more of the factors. The numerator in each fraction is the number of those environmental factors that lie within the bounds of environmental habitability for each. So, for example, the 1/4 value in the Subsurface Ice row of the Titan column means that there were data points available for four of the six environmental factors and that one of those environmental factors laid within the bounds set by the minimum and maximum of the livable conditions of extremophiles.

The chart clearly indicates that the most likely place that life could exist in the solar system is Enceladeus' hydrothermal vent system, which scores a five out of five on potential environmental factors—it is missing data on ionizing radioactivity. But the icy moon isn't alone at the top of the potentially habitable list. Mars and Europa both harbor environments that could be habitable to life, though the other candidates on the list seem less hospitable.

Ultimately there are a series of missions that will be focused on finding any microbial life that might exist at many of these locations, including Europa Clipper and the Mars Sample Return mission. This paper provides yet another reason why Enceladus should have its own mission in the works. But for now, having the framework that lets researchers and engineers focus their efforts on the most likely places to find one of the most sought-after discoveries in human history will help focus their efforts. Maybe something will come of it in the long run.

More information: 

• Dimitra Atri et al, Assessment of Microbial Habitability Across Solar System Targets. arXiv:2203.03171v2 [astro-ph.EP], doi.org/10.48550/arXiv.2203.03171

{ https://phys.org/space-news/ }

06-05-2024 om 18:12 geschreven door peter  

Why Venus May Be Our Best Bet For Finding Life In the Solar System

Venus and Earth once looked a lot alike. Could our planet’s forgotten early twin also contain life?

BY KIONA SMITH

 

One of the weirdest places in our Solar System may actually be a great place to search for alien life: the skies of Venus.

We don’t have evidence of life — or even indisputable evidence that life could survive — in any world but the one we currently live in. However, recent years have raised the tantalizing prospect that our Solar System, in which we thought we were alone, may be dotted with diverse, and deeply weird, homes for life: In dark water beneath the ice of Europa and Enceladus, in briny underground refugia on Mars, and even drifting in the acidic clouds of Venus.

“If it had liquid water in the past, and if we can really confirm that, then yes – Venus would likely be the planet I would place my bet on,” University of Wisconsin-Madison planetary scientist Sanjay Limaye tells Inverse.

Limaye and his colleagues, along with several other teams of researchers, presented their work in a recent collection of papers in the journal Astrobiology.

BETTING ON VENUS

In a series of recent papers, several teams of planetary scientists and astrobiologists argue that although the surface of Venus is undeniably an uninhabitable hellscape — you can’t do organic chemistry in a place that’s hot enough to melt lead — the sulfuric acid clouds might actually contain just enough water and other key chemicals for microbes to make a living.

What we know about Venus suggests that there’s something going on in our evil twin planet’s atmosphere that we don’t understand yet, whether it’s alien life or unusual chemical reactions that we’ve never seen anywhere else is still hotly debated.

A few years ago, a team of scientists detected a chemical called phosphine in Venus’s atmosphere. Here on Earth, the chemical reactions that create phosphine only ever happen inside living things, so some astrobiologists immediately got very excited about its presence on Venus. But in a recent paper, chemist Klaudia Mráziková of the Czech Academy of Sciences and her colleagues proposed a way that chemical reactions in the atmosphere could make phosphine without any help from life — and they’re not the first, although co-author Paul Rimmer of Cambridge University tells Inverse that he thinks their scenario is the “best hypothetical abiotic source for phosphine” so far.

Meanwhile, high in Venus’s atmosphere, something is absorbing huge amounts of ultraviolet radiation from the Sun. Over the last century, planetary scientists have suggested several chemical compounds, in different combinations, that could be absorbing the UV light, but no explanation quite fits, at least so far. And in a weirdly compelling coincidence, the shape of whatever’s absorbing the light, and the way it changes with the Venusian seasons, bears a striking resemblance to algal blooms in Earth’s oceans. Like the phosphine, it could be alien microbes busily doing photosynthesis, or it could be fascinating undiscovered chemistry.

And then there are the Mode 3 particles. These weirdly shaped particles in the lower cloud layers of Venus are less than a ten-thousandth of an inch wide, but that’s surprisingly large for particles floating in clouds. The Pioneer Venus mission discovered them in early 1971, when one of its instruments measured the tiny shadows of particles passing by. They’re not tiny spheres, but amorphous blobs, and some scientists wonder whether they might be cells living in the droplets of liquid that make up the clouds.

As incredible a discovery as that would be, the Mode 3 particles could also be an optical illusion; the result of overlapping shadows of round droplets, or a problem with the Pioneer Venus instrument’s calibration. They could also be grains of dust blown aloft from the dead surface of Venus, or something else entirely.

All of these mysteries could be clues pointing to alien life in the Venusian clouds – or they could be a stack of coincidences, which future astrobiologists will one day use as a cautionary tale. We just don’t know yet.

“There are far more unanswered questions about Venus than any other planet,” says Limaye.

A TALE OF TWO PLANETS

Venus is both the most and the least Earth-like planet we know of. It’s about the same size as our home world, and it’s also a rocky world, shrouded by an atmosphere, in the habitable zone of our Sun. But Venus is also a hellworld that rotates backwards, where temperatures on the ground could melt lead and the clouds rain sulfuric acid. But some scientists argue high above the deadly heat and crushing pressure of the surface, the acidic clouds actually aren’t so bad, that is if you’re a microbe evolved to like that sort of thing.

“Venus is often overlooked as a target for astrobiology,” Massachusetts Institute of Technology astrobiologist Janusz Petkowski tells Inverse. “This is an unfair assessment.” Petkowski and his colleagues recently published a paper in the journal Astrobiology presenting a case for a habitable niche in Venus’s clouds.

Once upon a time (almost 4 billion years ago, that is), the young planets Venus and Earth probably looked a lot alike. The fledgling Venus may even have had seas of liquid water, much like the environments where life probably emerged from chemistry on Earth. Researchers like Petkowski and Limaye argue that if Venus and Earth were similar during their youth, there’s no reason life couldn’t have emerged on Venus just like it did on Earth (it’s also plausible that the same thing was happening on Mars at around the same time).

But, as siblings sometimes do, the two planets took very different paths in their adolescent years. For various reasons, Venus’s atmosphere acted like a greenhouse, holding in heat until the seas boiled away and the clouds turned noxious and acidic. But that process took at least a hundred million years, and Petkowski, Limaye, and others are betting that some Venusian life may have evolved quickly enough to survive as the seas evaporated and the clouds got more and more acidic. If they’re right, then colonies of microbes could still be drifting in the upper layers of Venus’s atmosphere, where temperatures are more hospitable, clinging to droplets of fluid or tiny grains of dust that make up the clouds.

LIFE, UH, FINDS A WAY

“No life on Earth could actually survive in Venus’s clouds,” says Petkowski.” “But if we define habitability as an environment that allows any kind of organic chemistry to survive – maybe even life with different chemical composition and different biochemical solutions – then Venus’s clouds could be potentially habitable.”

The cloud layers of Venus’s upper atmosphere stay between freezing and boiling — exactly the right temperature range for life — but they’re made mostly of droplets of sulfuric acid, mingled with a few microscopically tiny droplets of water. No environment on Earth is remotely similar. But seeing how the scrappiest, stubbornest Earth life has adapted to milder versions of these challenges, astrobiologists can learn how life might adapt to the harsh conditions of Venus.

Here on Earth, for example, some microbes that live in acidic hot springs have found ways to neutralize the acid around them. Venus’s clouds are much more acidic than even the most caustic hot springs here on Earth, but given millions of years to adapt, it’s possible that microbes could keep pace with their changing environment. Petkowski and his colleagues suggest that multi-layered cell walls or acid-resistant membranes could also help microbes keep the acid out and the water in.

For now, that’s all speculation, but in recent lab experiments, Worcester Polytechnic Institute chemist Maxwell Seager and his colleagues found that some amino acids (chemical compounds that form the building blocks for proteins) are completely fine hanging out in a mixture of 98 percent sulfuric acid and 2 percent water. In previous experiments, the same team learned that nucleic acids (the molecules that store the genetic code) are also undaunted by super-acidic conditions.

That could be good news for life, but surviving the acid clouds is just one part of the challenge. Life — at least life as we know it — needs water to survive, and if there’s water in Venus’s clouds, it exists in the form of microscopic droplets, and even those are probably few and far between. In the driest places on Earth — carefully climate-controlled libraries — some resourceful microbes use nearby salt to pull just a few molecules of water out of the air. It’s not hard to imagine microbes on Venus doing something similar while clinging to a droplet of liquid in a cloud.

But could microbes spend their whole lives in the air? Some microbes here on Earth spend part of their life cycle in the clouds, but on Venus, sinking too deep into the haze below means a boiling death. Petkowski and colleagues say that resourceful microbes could lock themselves into armored balls called spores when their environments get too hot; inside the spore, a dormant microbe could wait until wind currents lift them back up to where things are cooler.

In other words, life finds a way. Or at least, it theoretically could. We need a lot more information to know for sure, or even to say how likely this scenario could be.

WILL WE EVER FIND A SMOKING GUN?

Upcoming missions to Venus may help answer some questions about what’s really going on in the sulfuric acid clouds: How much water is there? Are there organic molecules? Did Venus ever have liquid water on its surface? All of these are pieces of a much larger question: Could the clouds of Venus be habitable, even for a kind of life that we’ve never seen on Earth?

A commercial spaceflight company called Rocket Lab plans to launch its Venus Life Finder mission in December 2024. Venus Life Finder will look for organic molecules in the upper cloud layers. Finding these molecules won’t prove there’s life on Venus (despite the mission’s ambitious name), but it would show that the acidic clouds are home to the kind of chemistry that makes life work. This would be an encouraging sign.

NASA’s DAVINCI mission, which is planned for a 2029 launch, will study Venus’s atmosphere from orbit — and drop a probe into it. A couple of years later, in 2031, NASA’s VERITAS mission will study the planet’s surface and it’s interior. At around the same time, the European Space Agency’s EnVision mission will also use radar to study the interior of Venus from space.

All of these missions could help scientists understand whether Venus ever had liquid water on its surface, and how the planet’s atmosphere evolved over time (ratios of different chemical isotopes in a planet’s atmosphere can contain clues about its history). They may also help find explanations for the phosphine and even the mysterious UV absorber.

However, all of these missions are still years away even if everything goes according to plan. As JWST and Artemis have both shown us, it seldom does; they call it rocket science for a reason. And none of them will be capable of actually detecting life among the clouds of Venus , only clues about whether it could survive there. The only way to find real proof of life on Venus, according to researchers like Petkowski and Limaye, will be to scoop up a sample of the Venusian clouds and bring it home.

And that possibility is still decades away.

“It will take at least a couple of decades or longer, given the rate at which the previously selected missions are taking to actually be implemented,” says Limaye. “It will be a long time before we actually detect life elsewhere. It's not going to be a single experiment. It's going to take a lot of effort and different experiments and investigations and missions to determine.”

In the meantime, we can speculate, and scientists can find new ways to analyze the data they have. And we can all enjoy the possibility that our Solar System may be a lot wilder and a lot livelier than we thought.

{ https://www.inverse.com/ }

06-05-2024 om 17:36 geschreven door peter  

Multiple space agencies are looking to send crewed missions to the Moon’s southern polar region in this decade and the next. Moreover, they intend to create the infrastructure that will allow for a sustained human presence, exploration, and economic development. This requires that the local geography, resources, and potential hazards be scouted in advance and navigation strategies that do not rely on a Global Positioning System (GPS) developed. On Sunday, April 21st, the Chinese Academy of Sciences (CAS) released the first complete high-definition geologic atlas of the Moon.

This 1:2.5 million scale geological set of maps provides basic geographical data for future lunar research and exploration. According to the Institute of Geochemistry of the Chinese Academy of Sciences (CAS), the volume includes data on 12,341 craters, 81 impact basins, 17 types of lithologies, 14 types of structures, and other geological information about the lunar surface. This data will be foundational to China’s efforts in selecting a site for their International Lunar Research Station (ILRS) and could also prove useful for NASA planners as they select a location for the Artemis Base Camp.

Ouyang Ziyuan and Liu Jianzhong, a research professor and senior researcher from the Institute of Geochemistry of the CAS (respectively), oversaw these efforts. Since 2012, they have led a team of over 100 scientists and cartographers from relevant research institutions. The team spent more than a decade compiling scientific exploration data obtained by the many orbiters, landers, and rovers that are part of the Chinese Lunar Exploration Program (Chang’e), and other research about the origin and evolution of the Moon.

ccording to the CAS, the atlas includes an “upgraded lunar geological time scale” for “objectively” depicting the geological evolution of the Moon, including the lunar tectonics and volcanic activity that once took place. As a result, the volume could not only be significant in terms of lunar exploration and site selection. Still, it could also improve our understanding of the formation and evolution of Earth and the other terrestrial planets of the Solar System – Mercury, Venus, and Mars. As Jianzhong indicated in a CAS press release,

“The world has witnessed significant progress in the field of lunar exploration and scientific research over the past decades, which have greatly improved our understanding of the moon. However, the lunar geologic maps published during the Apollo era have not been changed for about half a century and are still being used for lunar geological research. With the improvements of lunar geologic studies, those old maps can no longer meet the needs of future scientific research and lunar exploration.”

Jianzhong also claims that the atlas could help inform future sample collection on the Moon. This includes the Chang’e-6 mission (consisting of an orbiter and lander), which launched this past Friday (May 3rd). The orbiter element will reach the Moon in a few days, and the lander element is expected to touch down the far side of the Moon by early June. By 2026, it will be joined by the Chang’e-7 mission, consisting of an orbiter, lander, rover, and a mini-hopping probe. While Chang’e-6 will obtain lunar soil and rock samples, Chang’e-7 will investigate resources and obtain samples of water ice and volatiles.

According to Gregory Michael, a senior scientist from the Free University of Berlin, the release of this atlas represents the culmination of decades of work, and not just by Chinese scientists:

“This map, in particular, is the first on a global scale to utilize all of the post-Apollo era data. It builds on the achievements of the international community over the last decades, as well as on China’s own highly successful Chang’e program. It will be a starting point for every new question of lunar geology and become a primary resource for researchers studying lunar processes of all kinds.”

Aside from updating data on lunar features and geology, the new maps reportedly double the resolution of the Apollo-era maps. These maps were compiled by the US Geological Survey in the 1960s and 70s using data from the Apollo missions. Among them was a global map at the scale of 1:5,000,000, though other regional maps and those that showed the terrain near the Apollo landing sites were of higher resolution. Geological and geographical information on the Moon has advanced considerably since then, requiring updated maps that reflect the objective of returning to the Moon with the intent to stay.

In addition to the Geologic Atlas of the Lunar Globe, the CAS also released a book called Map Quadrangles of the Geologic Atlas of the Moon. This document includes 30 sector diagrams that collectively form a visualization of the entire lunar surface. Both are available in Chinese and English, have been integrated into a digital platform called Digital Moon, and will eventually become available to the international research community.

Further Reading: 

• CAS

{ https://www.universetoday.com/ }

06-05-2024 om 17:22 geschreven door peter  

China Just Launched its Chang'e-6 Mission To Grab Samples From the Elusive Far Side of the Moon

Liftoff for the Moon’s newest robotic visitor.

BY DORIS ELÍN URRUTIA

 

Hector Retamal / AFP / Getty Images

China has launched the Chang’e-6 rover to the Moon.

Chang’e-6 is the latest of the Chang’e fleet, named after the Chinese goddess of the Moon. On Friday, the rover launched atop a Chinese Long March-5 rocket from Wenchang Space Launch Site in south China's Hainan Province. Chang’e-6 has successfully deployed into space, and it’s now heading for the enigmatic far side of the Moon.

Its predecessor, Chang’e-5, collected about 2 kilograms of lunar material from the near side of the Moon in late 2020. This was the first time since the 1970s that humanity had brought samples from the Moon to Earth. In early 2019, Chang’e-4 was the first mission ever to land on the far side of the Moon. Chang’e-6 builds upon all that work.

WHY GO TO THE FAR SIDE OF THE MOON?

Chang’e-6 will be a blend of both those earlier missions: It will retrieve samples from the far side of the Moon. Chang’e-6 will land in the largest and oldest known impact basin on the Moon. Known as the South Pole-Aitken (SPA) basin, it “stretches across nearly a quarter of the Moon,” according to the team that operates NASA’s Lunar Reconnaissance Orbiter.

It’s a fascinating place. The terrain is quite dramatic. The craters are also thought to have formed 3.9 billion years ago when life was just beginning to form on Earth. If the craters owe their existence to a chaotic episode of rocky bombardment, that same rocky rainfall likely struck Earth and the other terrestrial planets.

According to Chinese state media Xinhua, Chang’e-6 will deploy its robotic arm about 48 hours after landing. It will scoop up rocks and lunar dirt, called regolith. It will also excavate samples with a drill. The 53-day mission will culminate in samples, sealed away and ferried into an orbiter, flying to Earth. They’re expected to land in Inner Mongolia at the end of June.

Chang’e-6 is also carrying scientific instruments from other countries. “The Chang'e-6 mission is carrying four payloads developed through international cooperation. Scientific instruments from France, Italy, and the European Space Agency/Sweden are aboard the Chang'e-6 lander, and a small satellite from Pakistan is aboard the orbiter,” according to Xinhua.

In a year packed with lunar visits from other robots, like Odysseus of Houston-based Intuitive Machines, and Japan’s SLIM lander, Chang’e-6 is set to keep the momentum of 2024 Moon exploration building.

{ https://www.inverse.com/ }

06-05-2024 om 00:37 geschreven door peter  

Researcher Mark Christopher Lee claims the 'Tic Tac' UFO exposed by US whistle blowers 'hovered above a USO emerging from the ocean' 

(Image: Youtube/Nub TV)

The infamous 'Tic-Tac' UFO exposed by US whistle blowers was "hovering above an unidentified submerged object (USO) emerging from the ocean".

This is the claim by UFO researcher and filmmaker Mark Christopher Lee who said the US Military and Navy have been inundated with UFO and USO confrontations since the 1950s, with the navy dubbing USOs their "biggest threat" yet.

The infamous interaction with the Tic-Tac UFO captured by crew members from the USS Nimitz in 2004 marked a significant turning point in human history – with two former Navy pilots having come forward to share their discomforting encounters with the alien craft.

READ MORE: 

• Aliens may not have visited Earth due to one 'morbid' reason, space scientist suggests

But now expert Lee has thrown more questions into the mix as he boldly claimed the Tic-Tac UFO was seen hovering above a USO, something not previously addressed.

"USOs have been seen coming from the oceans for hundreds of years," Lee told the Daily Star. "Even Christopher Columbus saw a USO on his voyage to the new world and the US Navy has had plenty of confrontations with USOs since the 50s and have identified them as the biggest threat.

"Note that the Tic-Tac UFO reported by the recent US whistle blowers was seen hovering above a USO emerging from the ocean. [This makes me think UFOs and USOs] are linked and the tic tac and other UFOs are all able to enter the oceans at will.

"So, in my opinion, all UFOs are also USOs."

While training with a strike group off San Diego's coast back in November 2004, F/A-18 Squadron Lieutenant Alex Dietrich and ex-Navy pilot Dave Fravor spotted an unusual Tic-Tac shaped object via their infra-red cameras.

Nick Pope, a UFO expert who spent 21 years working at the Ministry of Defence and three running its UFO desk, previously told the Daily Star the pilots' claims put humankind in "disturbing territory".

He explained: "To have the Pentagon say 'these are authentic US Navy films' and they are on their own website... along with a note saying these sightings are still unexplained... takes us into new and frankly quite disturbing territory because these Top Guns don't spook easily. They are clearly encountering something outside of their knowledge base and their experience.

"Frankly there is only a couple of possibilities with this sort of thing. Either an adversary has made some sort of quantum leap breakthrough or this really could be some sort of first contact which is exactly how I imagined first contact would be, a sort of war of nerves – pushing at the boundaries, just testing, seeing how good our radar systems are.

"Are they going to pick us up, are they going to scramble jets, what are they going to do? Frankly, I'd rather this was extraterrestrial because if it is an adversary like China or Russia and they've got stuff... we're in big trouble.

"Usually with technological advances they come in steps and here it's like there are 10 steps missing. That just doesn't normally happen. It's as if you went from the Wright Brothers to a stealth fighter with nothing in between.''

READ NEXT:

• Mystery UFO-like trio of objects spotted in sky are 'not human-made or mechanical'
• 'I reached out to aliens telepathically – they arrived in UFO and made chilling move'
• Amanda Holden, 53, goes braless as she displays ageless figure in thigh-split dress
• Simple masturbation trick gives amazing orgasms – but only 3% of people do it
• Aliens 'signed treaty with government' as 'we've each got something the other wants'

{ https://www.dailystar.co.uk/news/ }

05-05-2024 om 21:19 geschreven door peter  

Manganese-Rich Sandstones Point to Earth-Like Environment on Ancient Mars

In May 2017, NASA’s Curiosity rover observed higher than usual amounts of manganese in the lakebed rocks within Gale crater, Mars. These sedimentary rocks have larger grain sizes than what is typical for the lakebed rocks in the crater. This may indicate that the original sediments were formed in a river, delta, or near the shoreline in the ancient lake. In a new paper, Dr. Patrick Gasda from Los Alamos National Laboratory and his colleagues discuss how manganese could have been enriched in these rocks — for example, by percolation of groundwater through the original sediments or through the rock afterward — and what oxidant could be responsible for the precipitation of manganese in the rocks. On Earth, manganese becomes enriched because of oxygen in the atmosphere and this process is often sped up by the presence of microbes. Microbes on Earth can use the many oxidation states of manganese as energy for metabolism; if life was present on ancient Mars, the increased amounts of manganese in these rocks along the lake shore would be a helpful energy source for life.

Mastcam mosaic from the Sol 1686 rover location looking behind the rover (downslope) at the transition point between the Sutton Island and Blunts Point Murray members. Images from Sols 1685-1689 display sedimentary textures of dark-toned manganese-rich sandstones and nearby rocks. Dashed line boxes in the large mosaic are shown as insets along the bottom of figure. Small red outlines show the approximate locations and extent of ChemCam observations. Throughout this transition area, dark-toned sandstones (presumably manganese-rich based on ChemCam observations at three locations) overlie light-toned materials. Insets from left to right: (a) Denning Brook, a manganese-rich fine-grained dark-toned sandstone ChemCam observation; (b) and (c) two light-toned blocks with cross-stratified textures, highlighted with yellow lines, 6 m away from Denning Brook and to the upper left in the large mosaic; (d) dark-toned materials (center of mosaic); and (E1) Newport Ledge, (E2) AEGIS post 1685a, (E3) Sugarloaf Mountain, three thin planar laminated dark-toned sandstones.

Image credit: NASA / Caltech-JPL / MSSS.

“It is difficult for manganese oxide to form on the surface of Mars, so we didn’t expect to find it in such high concentrations in a shoreline deposit,” Dr. Gasda said.

“On Earth, these types of deposits happen all the time because of the high oxygen in our atmosphere produced by photosynthetic life, and from microbes that help catalyze those manganese oxidation reactions.”

“On Mars, we don’t have evidence for life, and the mechanism to produce oxygen in Mars’ ancient atmosphere is unclear, so how the manganese oxide was formed and concentrated here is really puzzling.”

“These findings point to larger processes occurring in the Martian atmosphere or surface water and shows that more work needs to be done to understand oxidation on Mars.”

To measure manganese abundances in lakebed rocks within Gale crater, Dr. Gasda and co-authors used the ChemCam instrument onboard NASA’s Curiosity rover.

“ChemCam is an atomic emission spectroscopy instrument that uses laser-induced breakdown spectroscopy (LIBS) to quantify elemental abundances present in a target,” they explained.

“The ChemCam LIBS uses a pulsed laser emitting a 1,067 nm beam that is focused onto a target up to 7 m from the rover, which produces an analytical footprint of 350-550 μm.”

NASA’s Curiosity rover continues to search for signs that Mars’ Gale Crater conditions could support microbial life. 

Photo credit: NASA/JPL-Caltech/MSSS.

“Each laser pulse ablates and ionizes a small (nanograms to micrograms) amount of material.”

“Light emitted from the plasma formed by each laser pulse is collected by the ChemCam telescope, and spectra are recorded by the ultraviolet, violet, and visible to near infrared spectrometers.”

The sedimentary rocks explored by the Curiosity rover are a mix of sands, silts, and muds.

The sandy rocks are more porous, and groundwater can more easily pass through sands compared to the muds that make up most of the lakebed rocks in Gale crater.

{ https://www.sci.news/ }

05-05-2024 om 20:54 geschreven door peter  

Webb Probably Didn’t Detect Biosignature Gas on K2-18b

This illustration depicts NASA’s James Webb Space Telescope – the largest, most powerful, and most complex space science telescope ever built – fully unfolded in space.

(Credits: NASA/Adriana Manrique Gutierrez)

In 2023, astronomers reported a tentative detection of dimethyl sulfide — which is predominately produced by marine microbes on Earth and regarded as a biosignature gas — in the atmosphere of the super-Earth exoplanet K2-18b. In a paper published in the Astrophysical Journal Letters, University of California, Riverside astronomer Shang-Min Tsai and colleagues challenge this finding, but also outline how the NASA/ESA/CSA James Webb Space Telescope might verify the presence of dimethyl sulfide.

Rendering of the likely view on a Hycean world.

Image credit: Shang-Min Tsai / UCR.

K2-18 is a red dwarf located approximately 111 light-years away in the constellation of Leo.

Also known as EPIC 201912552, the star hosts two massive exoplanets: K2-18b and K2-18c.

First discovered in 2015, K2-18b has a radius of 2.2 times that of Earth and is about 8 times as massive.

The planet orbits its star every 33 days at a distance of approximately 0.15 AU and has an Earth Similarity Index of 0.73.

It receives 1.28 times the light intensity of Earth, and its equilibrium temperature is 28 degrees Fahrenheit (minus 2 degrees Celsius).

K2-18c, discovered in 2017, has a mass about 7.5 times that of Earth, orbits the host star one every 9 days, and is probably too hot to be in the habitable zone.

In 2023, astronomers reported a tentative detection of dimethyl sulfide (DMS) in the atmosphere of K2-18b.

“K2-18b gets almost the same amount of solar radiation as Earth,” Dr. Tsai said.

“And if atmosphere is removed as a factor, K2-18b has a temperature close to Earth’s, which is also an ideal situation in which to find life.”

“K2-18b’s atmosphere is mainly hydrogen, unlike our nitrogen-based atmosphere.”

“But there was speculation that K2-18b has water oceans, like Earth. That makes K2-18b a potentially Hycean world, which means a combination of a hydrogen atmosphere and water oceans.”

“What was icing on the cake, in terms of the search for life, is that last year researchers reported a tentative detection of DMS in the atmosphere of that planet, which is produced by ocean phytoplankton on Earth.”

“DMS is the main source of airborne sulfur on our planet and may play a role in cloud formation.”

Because the telescope data were inconclusive, Dr. Tsai and co-authors wanted to understand whether enough DMS could accumulate to detectable levels on K2-18b.

“The DMS signal from Webb was not very strong and only showed up in certain ways when analyzing the data,” Dr. Tsai said.

“We wanted to know if we could be sure of what seemed like a hint about DMS.”

This art’s tisimpression shows planets K2-18b and c and their host star.

Image credit: NASA / ESA / Hubble / M. Kornmesser.

Based on computer models that account for the physics and chemistry of DMS, as well as the hydrogen-based atmosphere, the researchers found that it is unlikely the data show the presence of DMS.

“The signal strongly overlaps with methane, and we think that picking out DMS from methane is beyond this instrument’s capability,” Dr. Tsai said.

However, the scientists believe it is possible for DMS to accumulate to detectable levels.

For that to happen, plankton or some other life form would have to produce 20 times more DMS than is present on Earth.

Detecting life on exoplanets is a daunting task, given their distance from Earth.

To find DMS, Webb would need to use an instrument better able to detect infrared wavelengths in the atmosphere than the one used last year.

Fortunately, the telescope will use such an instrument later this year, revealing definitively whether DMS exists on K2-18b.

“The best biosignatures on an exoplanet may differ significantly from those we find most abundant on Earth today,” said Dr. Eddie Schwieterman, an astrobiologist at the University of California, Riverside.

“On a planet with a hydrogen-rich atmosphere, we may be more likely to find DMS made by life instead of oxygen made by plants and bacteria as on Earth.”

• Shang-Min Tsai et al. 2024. Biogenic Sulfur Gases as Biosignatures on Temperate Sub-Neptune Waterworlds. ApJL 966, L24; doi: 10.3847/2041-8213/ad3801

LINKS VIDEOS

• https://youtu.be/2WCzlACGULs

• https://youtu.be/e_uwbGVX1Lg

{ https://www.sci.news/ }

05-05-2024 om 20:38 geschreven door peter  

The mirror is called a primary/tertiary mirror because it comprises two optical surfaces with different curvatures. The primary mirror is 8.4 meters, while the tertiary mirror is 5 meters in diameter. The pair of surfaces are combined into one large structure. The unique design reduces the telescope’s engineering complexity without reducing its impressive light-gathering capability. It can be rotated quickly and also settles quickly.

The outer surface forms the primary mirror. It captures light from space first, then that light reflects upwards to the 3.4-meter secondary mirror. After that, it’s reflected back down to the inner 5.0-meter surface that forms the tertiary mirror. Then, the light is sent to the camera.

The primary mirror’s size is critical because it determines how much light the telescope can collect. More light means astronomers can study very faint or distant objects. The VRO’s design allows the camera to capture a large area of sky the size of 7 full moons across in a single image.

via GIPHY

Only meticulous engineering and construction can build a telescope like this. One of the stages is putting the reflective and protective coatings on the mirrors. The VRO announced that the primary/tertiary mirror has its first coating.

The VRO has a special onsite coating chamber built just for this purpose. It’s a 128-ton chamber on the observatory’s maintenance floor. It uses a process called magnetron sputtering to apply coatings. The chamber will be reused during the telescope’s lifetime whenever the mirror needs re-coating.

The chamber can apply coatings of different reflective materials alone or in combinations. It took a lot of work to determine the perfect coating for reflectivity and durability. Researchers tested different coatings on a steel stand-in mirror.

The first layer was an adhesive layer of nickel-chromium. Next came an incredibly thin layer of silver weighing only 64 grams spread over the 8.4-meter mirror. On top of that, another nickel-chromium adhesive layer, then a protective layer of silicon nitride to shield the reflective layer.

The person in charge of these precision coatings is Tomislav Vucina, the Senior Coating Engineer. Vucina describes the coatings as a balancing act. “This outer layer needs to be thick enough that it’s not worn off by cleaning,” said Vucina, “but not so thick that it absorbs too many photons and prevents the mirror from meeting Rubin’s scientific requirements.”

Until these coatings were applied, the glass was just glass. Highly specialized glass, but glass nonetheless. Now that the glass has received its reflective silver coating, it’s truly a mirror.

The application process took only 4.5 hours, nothing compared to the 7 years required to build the primary/tertiary mirror. Vucina and his team subjected the mirror to a battery of tests: reflectivity, adhesion, pinhole, and cosmetic. According to Vucina, the application process was successful.

“This was a very well-conducted project from every angle,” said Vucina, “thanks to a combination of careful planning and the technical skills of our excellent team.”

It’s been a long road to completion for the VRO. But after a long wait, first light is rapidly approaching. Excitement and anticipation for the observatory’s unique and powerful scientific contribution is growing. Its main output is the decade-long Legacy Survey of Space and Time.

“We’re extremely excited that both mirrors are now coated and will be installed on the telescope very soon,” said Sandrine Thomas, Deputy Director for Rubin Construction. “The combined reflectivity of these mirrors will enable Rubin to detect very faint and far-away objects, leading to great science!”

{ https://www.universetoday.com/ }

05-05-2024 om 18:29 geschreven door peter  

The JWST is astronomers’ best tool for probing exoplanet atmospheres. Its capable instruments can dissect the light passing through a distant world’s atmosphere and determine its chemical components. Scientists are interested in everything the JWST finds, but when it finds something indicating the possibility of life it seizes everyone’s attention.

That’s what happened in September 2023, when the JWST found dimethyl sulphide (DMS) in the atmosphere of the exoplanet K2-18b.

K2-18b orbits a red dwarf star about 124 light-years away. It’s a sub-Neptune with about 2.5 times Earth’s radius and 8.6 Earth masses. The exoplanet may be a Hycean world, a temperate ocean-covered world with a large hydrogen atmosphere.

In October 2023, researchers announced the tentative detection of dimethyl sulphide in K2-18b’s atmosphere. They found it in JWST observations of the planet’s atmospheric spectrum. “The spectrum also suggests potential signs of dimethyl sulphide (DMS), which has been predicted to be an observable biomarker in Hycean worlds, motivating considerations of possible biological activity on the planet,” the researchers wrote.

The DMS caught people’s attention because it’s produced by living organisms here on Earth, mostly by marine microbes. So, finding it on an ocean world is cause for a deeper look. A team of researchers from the USA, Germany, and the UK examined the detection to see how it fits with atmospheric models.

“The best biosignatures on an exoplanet may differ significantly from those we find most abundant on Earth today.”

Eddie Schwieterman, astrobiologist, University of California, Riverside

They published their results in a paper in the Astrophysical Journal Letters. It’s titled “Biogenic Sulfur Gases as Biosignatures on Temperate Sub-Neptune Waterworlds.” The lead author is Shang-Min Tsai, a University of California Riverside project scientist.

Most of the thousands of exoplanets we’ve discovered are nothing like Earth. Habitability is impossible according to every known metric. But some are more intriguing. Some, like K2-18b, are more difficult to understand regarding habitability.

There’s some disagreement over what type of planet K2-18b is. It was the first exoplanet scientists ever detected water vapour on. It may be the first example of a Hycean world if they exist.

There are some clear differences between K2-18b and Earth. Our atmosphere is dominated by nitrogen, which makes up about 78%. K2-18b’s atmosphere is dominated by hydrogen. But it’s enough like Earth in some ways that scientists are keen to understand it better.

“This planet gets almost the same amount of solar radiation as Earth. And if atmosphere is removed as a factor, K2-18b has a temperature close to Earth’s, which is also an ideal situation in which to find life,” said lead author Shang-Min Tsai.

The researchers who found DMS in K2-18b’s atmosphere also found carbon dioxide and methane. Finding CO₂ and CH₄ is noteworthy, but finding DMS with them is even more intriguing.

“What was icing on the cake, in terms of the search for life, is that last year these researchers reported a tentative detection of dimethyl sulfide, or DMS, in the atmosphere of that planet, which is produced by ocean phytoplankton on Earth,” Tsai said. DMS is oxidized in Earth’s oceans and is the planet’s main source of atmospheric sulphur.

However, the 2023 findings were not conclusive. There were hints of DMS but nothing strong enough to convince scientists and overcome their professional skepticism. “The potential inference of DMS is of high importance, as it is known to be a robust biomarker on Earth and has been extensively advocated to be a promising biomarker for exoplanets,” the authors of the 2023 paper explained.

“The DMS signal from the Webb telescope was not very strong and only showed up in certain ways when analyzing the data,” Tsai said. “We wanted to know if we could be sure of what seemed like a hint about DMS.”

The JWST has no alarm bell and flashing indicator that lights up and says, ‘Biomarker Detected!’ It produces data that must be processed to tease out its secrets. Scientists also rely on battle-tested climate and atmospheric chemistry models to understand what the JWST sees.

“In this study, we explore biogenic sulphur across a wide range of biological fluxes and stellar UV environments,” the researchers write. They performed experiments with a 2D photochemical model and a 3D general circulation model (GCM.) According to Tsai and his co-researchers, the data is unlikely to show the presence of DMS in K2-18b’s atmosphere.

“The signal strongly overlaps with methane, and we think that picking out DMS from methane is beyond this instrument’s capability,” Tsai said.

That doesn’t mean that DMS is ruled out. It’s possible that the chemical could build up to detectable levels if plankton or some other life form were producing it. But, they’d have to produce about 20 times more DMS than there is on Earth.

Professor Madhusudhan from Cambridge University is the lead author of the 2023 paper on K2-18b’s atmosphere. He’s being touted in the media as the man who discovered alien life on another planet. He’s clearly uncomfortable with some of the hyperbole, but the message is becoming bigger than the messenger.

This study will probably put a damper on the media’s enthusiasm. But for people who follow science, this is just another instance of science correcting itself.

The fact is, we’re only groping our way toward understanding exoplanet atmospheres. Scientists have a powerful tool in the JWST, but it has limitations. It measures light in extreme detail and leaves the rest up to us. “We find that it is challenging to identify DMS at 3.4 ?m where it strongly overlaps with CH₄,” the authors explain. But, they continue, “it is more plausible to detect DMS … in the mid-infrared between 9 and 13 ?m,” the authors explain.

That means there’s hope for K2-18b. These observations were taken with the JWST’s near-infrared instruments, the NIRISS and the NIRSpec. Sometime next year, the JWST will examine the exoplanet’s atmosphere again, this time with its mid-infrared instrument MIRI. This instrument should tell us definitively whether DMS is present.

Scientists’ understanding of biosignatures has grown more detailed. Instead of searching for biosignatures like the ones on Earth, scientists are taking a larger, more holistic view of biosignatures and the nature of the atmospheres they might be present in.

“The best biosignatures on an exoplanet may differ significantly from those we find most abundant on Earth today. On a planet with a hydrogen-rich atmosphere, we may be more likely to find DMS made by life instead of oxygen made by plants and bacteria as on Earth,” said UCR astrobiologist Eddie Schwieterman, a senior author of the study.

The team’s work does show that sulphur could be a detectable biomarker for Hycean worlds. “The moderate threshold for biological production suggests that the search for biogenic sulphur gases as one class of potential biosignature is plausible for Hycean worlds,” they conclude.

{ https://www.universetoday.com/ }

05-05-2024 om 18:16 geschreven door peter  

As mentioned, astronomers rely extensively on machine learning algorithms to sort through the volumes of data obtained by modern telescopes and instruments. This practice began about a decade ago and has since grown by leaps and bounds to the point where AI has been integrated into the entire research process. As ICRA President and the study’s lead author Yu Wang told Universe Today via email:

“Astronomy has always been driven by data and astronomers are some of the first scientists to adopt and employ machine learning. Now, machine learning has been integrated into the entire astronomical research process, from the manufacturing and control of ground-based and space-based telescopes (e.g., optimizing the performance of adaptive optics systems, improving the initiation of specific actions (triggers) of satellites under certain conditions, etc.), to data analysis (e.g., noise reduction, data imputation, classification, simulation, etc.), and the establishment and validation of theoretical models (e.g., testing modified gravity, constraining the equation of state of neutron stars, etc.).”

Data analysis remains the most common among these applications since it is the easiest area where machine learning can be integrated. Traditionally, dozens of researchers and hundreds of citizen scientists would analyze the volumes of data produced by an observation campaign. However, this is not practical in an age where modern telescopes are collecting terabytes of data daily. This includes all-sky surveys like the Very Large Array Sky Survey (VLASS) and the many phases conducted by the Sloan Digital Sky Survey (SDSS).

To date, LLMs have only been applied sporadically to astronomical research, given that they are a relatively recent creation. But according to proponents like Wang, it has had a tremendous societal impact and has a lower-limit potential equivalent to an “Industrial Revolution.” As for the upper limit, Wang predicts that that could range considerably and could perhaps result in humanity’s “enlightenment or destruction.” However, unlike the Industrial Revolution, the pace of change and integration is far more rapid for AI, raising questions about how far its adoption will go.

To determine its potential for the field of astronomy, said Wang, he and his colleagues adopted a pre-trained GPT model and fine-tuned it to identify astronomical phenomena:

“OpenAI provides pre-trained models, and what we did is fine-tuning, which involves altering some parameters based on the original model, allowing it to recognize astronomical data and calculate results from this data. This is somewhat like OpenAI providing us with an undergraduate student, whom we then trained to become a graduate student in astronomy. 

“We provided limited data with modest resolution and trained the GPT fewer times compared to normal models. Nevertheless, the outcomes are impressive, achieving an accuracy of about 90%. This high level of accuracy is attributable to the robust foundation of the GPT, which already understands data processing and possesses logical inference capabilities, as well as communication skills.”

To fine-tune their model, the team introduced observations of various astronomical phenomena derived from various catalogs. This included 2000 samples of quasars, galaxies, stars, and broad absorption line (BAL) quasars from the SDSS (500 each). They also integrated observations of short and long gamma-ray bursts (GRBs), galaxies, stars, and black hole simulations. When tested, their model successfully classified different phenomena, distinguished between types of quasars, inferred their distance based on redshift, and measured the spin and inclination of black holes.

“This work at least demonstrates that LLMs are capable of processing astronomical data,” said Wang. “Moreover, the ability of a model to handle various types of astronomical data is a capability not possessed by other specialized models. We hope that LLMs can integrate various kinds of data and then identify common underlying principles to help us understand the world. Of course, this is a challenging task and not one that astronomers can accomplish alone.”

Of course, the team acknowledges that the dataset they experimented with was very small compared to the data output of modern observatories. This is particularly true of next-generation facilities like the Vera C. Rubin Observatory, which recently received its LSST camera, the largest digital camera in the world! Once Rubin is operational, it will conduct the ten-year Legacy Survey of Space and Time (LSST), which is expected to yield 15 terabytes of data per night! Satisfying the demands of future campaigns, says Wang, will require improvements and collaboration between observatories and professional AI companies.

Nevertheless, it’s a foregone conclusion that there will be more LLM applications for astronomy in the near future. Not only is this a likely development, but a necessary one considering the sheer volumes of data astronomical studies are generating today. And since this is likely to increase exponentially in the near future, AI will likely become indispensable to the field of study.

Further Reading: 

• arXiv

{ https://www.universetoday.com/ }

05-05-2024 om 17:59 geschreven door peter  

You’ve seen the Sun, but you’ve never seen the Sun like this. This single frame from a video captured by ESA’s Solar Orbiter mission shows the Sun looking very …. fluffy!  You can see feathery, hair-like structures made of plasma following magnetic field lines in the Sun’s lower atmosphere as it transitions into the much hotter outer corona. The video was taken from about a third of the distance between the Earth and the Sun.

See the full video below, which shows unusual features on the Sun, including coronal moss, spicules, and coronal rain.  

Solar Orbiter recorded this video on September 27, 2023 using its Extreme Ultraviolet Imager (EUI) instrument.

ESA said the brightest regions are around one million degrees Celsius, while cooler material looks darker, as it absorbs radiation.

So, just what is coronal moss? It’s what gives the Sun its fluffy appearance here. These peculiar structures on the Sun resemble the moss we find on Earth, in that it appears like fine, lacy features. But on the Sun, they usually can be found around the center of sunspot groups, where magnetic conditions are strong and large coronal loops are forming. The moss is so hot, most instruments can’t detect them. The moss spans two atmospheric layers, the chromosphere and corona.

Features on the Sun’s surface, as seen by Solar Orbiter.

Credit: ESA & NASA/Solar Orbiter/EUI Team

Spicules, as their name implies, are tall spires of gas seen on the solar horizon that reach up from the Sun’s chromosphere. These can reach up to a height of 10,000 km (6,000 miles).

At about 0:30 in the video, you’ll see coronal rain. This material is cooler than the rest of the solar surface (probably less than 10,000 °C) versus the one million degrees C of the coronal loops. The rain is made of higher-density clumps of plasma that fall back towards the Sun under the influence of gravity.

Did you see the small eruption in the center of the field of view at about 0:20 seconds in the video? , with cooler material being lifted upwards before mostly falling back down. It’s not small at all — this eruption is bigger than Earth!

Missions like Solar Orbiter, the Parker Solar Probe and the Solar Dynamics Observatory are giving us unprecedented views of the Sun, helping astronomers to learn more about the dynamic ball of gas that powers our entire Solar System.

Further reading: 

• ESA

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05-05-2024 om 17:45 geschreven door peter  

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05-05-2024 om 00:21 geschreven door peter