#planetary geophysics

[mindblowingscience]

According to seismic data obtained using NASA's InSight lander, which monitored the red planet's innards for four years, Mars' center is a liquid iron alloy, with surprisingly large amounts of sulfur and oxygen mixed in.

It's information that can help scientists better understand Mars' history, and why it is different from Earth – one planet an arid, lifeless dustball, the other lush and teeming.

"In 1906, scientists first discovered the Earth's core by observing how seismic waves from earthquakes were affected by traveling through it," says geologist Vedran Lekic of the University of Maryland.

"More than a hundred years later, we're applying our knowledge of seismic waves to Mars. With InSight, we're finally discovering what's at the center of Mars and what makes Mars so similar yet distinct from Earth."

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[typhlonectes]

Dwarf planet Eris is ‘squishier’ than expected

University of California, Santa Cruz Professor of Planetary Sciences Francis Nimmo recently co-authored a Science Advances paper about the internal structure of the dwarf planet Eris. Eris is about the size of Pluto but around 50% farther from the sun. The discovery of Eris in the Kuiper Belt beyond Neptune in 2005 prompted the debate that ultimately reclassified Pluto as a dwarf planet. It was an interest in Pluto that drew UC Santa Cruz researcher Francis Nimmo to study Eris. Nimmo was visiting Michael Brown—one of the discoverers of Eris—at the California Institute of Technology about six months ago and realized some of Brown’s new, unpublished data could help reveal information about the properties of Eris. The two worked on models for the next several months and published their results in a Science Advances paper. Two main pieces of information led to their results. The first important clue is that Eris and its moon, Dysnomia, always face the same way toward each other. The main, unexpected result of Nimmo and Brown’s model is that Eris is surprisingly dissipative, or “squishy”...

Read more: https://charmingscience.com/dwarf-planet-eris-is-squishier-than-expected/

[fuckyeahfluiddynamics]

Reimagining Mars' Interior

Older models of Mars assumed a liquid metal core beneath a solid mantle of silicates, but recent studies indicate that structure is missing at least one layer. Using data from the InSight lander's seismometer, two teams independently calculated that a liquid silicate layer must surround the planet's core.  (Image credit: Mars - NASA/JPL-Caltech/University of Arizona, illustration - J. Sieben/J. Keisling; research credit: H. Samuel et al. and A. Khan et al.; via Physics Today) Read the full article

[honestlyvan]

3 and 6 for your personal takes on post-war Cybertron? owo

3. Climate or weather

So during the war, especially after the Energon wells started getting dried up or diverted, Cybertron's atmosphere developed into a bit of a dustbowl due to many of the mechanimal macrofauna that had critical atmospheric and geological maintenance functions suffered from a lack of access to fuel and the widespread habitat destruction. Static storms weren't actually that common outside of the Sea of Rust and Mithric Sea before the war, but with the fine dust in the air not being filtered out anymore and the ground layers being subject to more erosion due to a lack of maintenance, there was at one point several electric storm supercells just, like... roiling around the planet.

They died down once the Allspark was removed and Energon production on the planet stopped -- meaning that after the activation of the Omega Lock, surviving Cybertronians had an opportunity to start from a neutral system with little established weather patterns to deal with. This was not good! This was, in fact, a huge issue because none of their solar and wind power would work, with unshifting air and high vapour clouds stopping a lot of the radiation. They had to start rapidly reintroducing macrofauna and try to get some kind of a climate going before the population grew too large to support all over.

6. Architecture or buildings

The basic.... thing, the basic building block of Cybertronian construction, is a bent metal sheet riveted together with another metal sheet, because a lot of the ground is either thin metal sheets with little gaps, big metal sheets with big gaps or mixed metal gravel that is easy to melt into sheets. A lot of lower-end Cybertronian housing looks like origami, because the sheets aren't even riveted, they're just stamped together in features that look like folds from a distance. Post-war this kind of decorative stamping and clever use of scarce material meant that a lot of the newer buildings were designed to have their visual appeal be in the cleverness of the construction, the illusion of being made out of a single sheet of metal despite having impossible dimensions for it.

(It's debated whether this was some kind of a political statement about the unity of the species. Of course, you'd probably have to ask the architects, but reconstruction era architecture stayed popular well into the second golden age, for being both economic and aesthetically pleasing.)

[historysurvivalguide]

Most comprehensive catalogue of volcanoes on Venus ever made was just released

Data:

Paper:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JE007753

[quotesfrommyreading]

Europa is enveloped in a thick coat of water ice. (Some other moons in our solar system have ice made of methane and nitrogen—the cosmos is a weird place.) The criss-crossing lines visible in the new pictures are actually cracks and fissures in that frozen exterior. Scientists suspect that they’re caused by the stretching and squashing that Europa experiences as it orbits giant Jupiter. The moon’s terrain is sprinkled with chemical compounds such as sodium chloride and magnesium sulfate—more commonly known to Earthlings as table salt and Epsom salt—and they could indicate briny waters below.

Scientists got their best evidence that a Europan ocean might exist two decades ago, when that earlier NASA spacecraft detected a magnetic connection between Europa and Jupiter that could easily be explained by the presence of a salty, global sea. This deep into the solar system, Europa’s underground ocean wouldn’t feel the warmth of the sun; it would stay liquid because of Jupiter’s gravitational tugging. In recent years, telescopes have detected signs of plumes of water vapor spewing out of the cracks and into space. Scientists believe that Europa’s ocean could be as old as the moon itself, about 4 billion years or so, which would give life plenty of time and a stable environment in which to evolve, Phillips said.

The data suggest that Europa has a rocky mantle—the layer between the moon’s crust and core—and when rock and water come together, magical things can happen: Chemical interactions between them are known to produce hydrogen-rich materials for tiny creatures to metabolize. “On our own planet, hydrothermal systems at the seafloor provide energy for communities of microorganisms,” Samantha Trumbo, a planetary scientist at Cornell who studies icy ocean worlds like Europa, told me.

The upcoming NASA mission, named Clipper—a nod to the speedy, lightweight vessels favored by 19th-century merchants—will study nearly every bit of the Europan surface. If it gets lucky, the spacecraft could fly through some plume particles, take a sip, and analyze the contents. Alyssa Rhoden, a planetary geophysicist at the Southwest Research Institute who studies Europa, is most excited about a Clipper instrument designed to detect warmer-than-usual spots on the moon’s surface. “When you look at Europa’s surface, you can see a lot of pits where the surface seems to have dropped down a little bit, places where the surface has been disrupted,” Rhoden told me. “We think that that’s happening from heating coming from below.” That signature could simply indicate the presence of melted bits of ice near the frigid crust—or it could mean a roiling sea has floated toward the surface, perhaps bringing any tiny inhabitants with it.

The Clipper mission is not meant to find definitive proof that life exists on Europa, only explore whether the moon has the right conditions and chemistry to make life possible. Evidence of life will require more missions, guided by Clipper’s data, that could land on the Europan surface and drill into the ice. NASA is also searching for life elsewhere in the solar system, notably on Mars, where a rover is collecting samples from a dried-up river delta. But Europa is a more tantalizing target, and so are the other ocean moons sprinkled across the solar system, such as Enceladus and Titan, which orbit Saturn, and Triton, around Neptune. The Mars mission is designed to search for signs of fossilized life that existed several billion years ago, when water once flowed on the planet. “It’s quite possible that Mars could have had life in the past, in a warmer-weather era, and it’s possible that there are subsurface pockets on Mars that could have remnants of this living biosphere,” Phillips said. “But on somewhere like Europa, life could exist there now.”

And what might humanity, by way of carefully engineered machines, find on Europa, once we’ve figured out which melty bits to inspect? “I would love for there to be Europan whales swimming around in that ocean,” Phillips said with a laugh. But alien life, if it exists, is likely to be small and simple. Energy sources are limited in the Europan depths, and scientists don’t think the environment can support the development of more complex organisms, Phillips said. Still, even the discovery of a single microbe would mark an explosive event in human history. It would mean that life had managed to spring up in two different places around the same star—in a universe absolutely brimming with stars. If it happened more than once here, in our own solar system, it’s likely happened elsewhere in the cosmos, around someone else’s sun. This is why scientists are so eager to catch a glimpse of Europa, and prepare as much as they can for the exploration to come. “We all want it to be water,” Rhoden said. “We all want it to be a cool plumbing system in the shell with lots of activity, and someday we’ll get down there and find little Europan sea urchins clinging to the bottom of the ice.”

  —  There’s Hope for Life on Europa, a Distant Moon

[fumpkins]

Physicists describe new type of aurora

For centuries, people in the high latitudes have actually been enthralled by auroras—the northern and southern lights. Yet even after all that time, it appears the ethereal, dancing ribbons of light above Earth still hold some tricks.

In a new research study, physicists led by the University of Iowa report a new function to Earth’s climatic light program. Examining video taken almost twenty years back, the scientists describe numerous circumstances where an area of the diffuse aurora—the faint, background-like radiance accompanying the more brilliant light frequently connected with auroras—goes dark, as if scrubbed by a huge blotter. Then, after a brief duration of time, the blacked-out area all of a sudden comes back.

The scientists state the habits, which they call “diffuse auroral erasers,” has actually never ever been discussed in the clinical literature. The findings appear in the Journal of Geophysical Research Space Physics.

Auroras take place when charged particles streaming from the sun—called the solar wind—communicate with Earth’s protective magnetic bubble. Some of those particles leave and fall towards our world, and the energy launched throughout their crashes with gases in Earth’s environment create the light connected with auroras.

“The biggest thing about these erasers that we didn’t know before but know now is that they exist,” states Allison Jaynes, assistant teacher in the Department of Physics and Astronomy at Iowa and research study co-author. “It raises the concern: Are these a typical phenomenon that has been neglected, or are they uncommon?

“Knowing they exist means there is a process that is creating them,” Jaynes continues, “and it may be a process that we haven’t started to look at yet because we never knew they were happening until now.”

It was on March 15, 2002, that David Knudsen, a physicist at the University of Calgary, established a camera in Churchill, a town along Hudson Bay in Canada, to movie auroras. Knudsen’s group was a little discouraged; the projection required clear, dark skies—typically ideal conditions for seeing auroras—however no stunning lighting was taking place. Still, the group was utilizing a cam specifically created to catch low-level light, just like night-vision safety glasses.

Though the researchers saw just mainly darkness as they looked up with their own eyes, the video camera was getting all sorts of auroral activity, consisting of an uncommon series where locations of the diffuse aurora vanished, then returned.

Knudsen, taking a look at the video as it was being taped, doodled in his note pad, “pulsating ‘black out’ diffuse glow, which then fills in over several seconds.”

“What surprised me, and what made me write it in the notebook, is when a patch brightened and turned off, the background diffuse aurora was erased. It went away,” states Knudsen, a Fort Dodge, Iowa, local who has actually studied aurora for more than 35 years and is a co-author on the research study. “There was a hole in the diffuse aurora. And then that hole would fill back in after a half-minute or so. I had never seen something like that before.”

The note lay inactive, and the video unstudied, up until Iowa’s Jaynes commended finish trainee Riley Troyer to examine. Jaynes learnt more about Knudsen’s recording at a clinical conference in 2010 and referenced the eraser note in her doctoral thesis on diffuse aurora a couple of years later on. Now on the professors at Iowa, she wished to discover more about the phenomenon.

“I knew there was something there. I knew it was different and unique,” states Jaynes, assistant teacher in the Department of Physics and Astronomy. “l had some ideas how it could be analyzed, but I hadn’t done that yet. I handed it to Riley, and he went much further with it by figuring out his own way to analyze the data and produce some significant conclusions.”

Troyer, from Fairbanks, Alaska, used up the task with gusto.

“I’ve seen hundreds of auroras growing up,” states Troyer, who remains in his 3rd year of doctoral research studies at Iowa. “They’re part of my heritage, something I can study while keeping ties to where I’m from.”

Troyer developed a software application to type in on frames in the video when the faint erasers showed up. In all, he cataloged 22 eraser occasions in the two-hour recording.

“The most valuable thing we found is showing the time that it takes for the aurora to go from an eraser event (when the diffuse aurora is blotted out) to be filled or colored again,” states Troyer, who is the paper’s matching author, “and how long it takes to go from that erased state back to being diffuse aurora. Having a value on that will help with future modeling of magnetic fields.”

Jaynes states learning more about scattered auroral erasers belongs to studying DNA to comprehend the whole body.

“Particles that fall into our atmosphere from space can affect our atmospheric layers and our climate,” Jaynes states. “While particles with diffuse aurora may not be the main cause, they are smaller building blocks that can help us understand the aurora system as a whole, and may broaden our understanding how auroras happen on other planets in our solar system.”

###

Study co-authors are Sarah Jones, from NASA Goddard Space Flight Center and who was part of Knudsen’s group in Churchill, and Trond Trondsen, with Keo Scientific Ltd., who developed the video camera that shot the diffuse aurora.

NASA supported the information analysis.

New post published on: https://livescience.tech/2021/05/07/physicists-describe-new-type-of-aurora/

[spacetimewithstuartgary]

The remains of an ancient planet lie deep within Earth

In the 1980s, geophysicists made a startling discovery: two continent-sized blobs of unusual material were found deep near the center of the Earth, one beneath the African continent and one beneath the Pacific Ocean. Each blob is twice the size of the Moon and likely composed of different proportions of elements than the mantle surrounding it.

Where did these strange blobs—formally known as large low-velocity provinces (LLVPs)—come from? A new study led by Caltech researchers suggests that they are remnants of an ancient planet that violently collided with Earth billions of years ago in the same giant impact that created our Moon.

The study, published in the journal Nature on November 1, also proposes an answer to another planetary science mystery. Researchers have long hypothesized that the Moon was created in the aftermath of a giant impact between Earth and a smaller planet dubbed Theia, but no trace of Theia has ever been found in the asteroid belt or in meteorites. This new study suggests that most of Theia was absorbed into the young Earth, forming the LLVPs, while residual debris from the impact coalesced into the Moon.

The research was led by Qian Yuan, O.K. Earl Postdoctoral Scholar Research Associate in the laboratories of both Paul Asimow (MS '93, PhD '97), the Eleanor and John R. McMillan Professor of Geology and Geochemistry; and Michael Gurnis, the John E. And Hazel S. Smits Professor of Geophysics and Clarence R. Allen Leadership Chair, director of Caltech’s Seismological Laboratory, and director of the Schmidt Academy for Software Engineering at Caltech.

Scientists first discovered the LLVPs by measuring seismic waves traveling through the earth. Seismic waves travel at different speeds through different materials, and in the 1980s, the first hints emerged of large-scale three-dimensional variations deep within the structure of Earth. In the deepest mantle, the seismic wave pattern is dominated by the signatures of two large structures near the Earth's core that researchers believe possess an unusually high level of iron. This high iron content means the regions are denser than their surroundings, causing seismic waves passing through them to slow down and leading to the name "large low velocity provinces." 

Yuan, a geophysicist by training, was attending a seminar about planet formation given by Mikhail Zolotov, a professor at Arizona State University, in 2019. Zolotov presented the giant-impact hypothesis, while Qian noted that the Moon is relatively rich in iron. Zolotov added that no trace had been found of the impactor that must have collided with the Earth.

"Right after Mikhail had said that no one knows where the impactor is now, I had a 'eureka moment' and realized that the iron-rich impactor could have transformed into mantle blobs," says Yuan.

Yuan worked with multidisciplinary collaborators to model different scenarios for Theia's chemical composition and its impact with Earth. The simulations confirmed that the physics of the collision could have led to the formation of both the LLVPs and the Moon. Some of Theia's mantle could have become incorporated into the Earth's own, where it ultimately clumped and crystallized together to form the two distinct blobs detectable today at Earth's core–mantle boundary today; other debris from the collision mixed together to form the Moon.

Given such a violent impact, why did Theia's material clump into the two distinct blobs instead of mixing together with the rest of the forming planet? The researchers' simulations showed that much of the energy delivered by Theia's impact remained in the upper half of the mantle, leaving Earth’s lower mantle cooler than estimated by earlier, lower-resolution impact models. Because the lower mantle was not totally melted by the impact, the blobs of iron-rich material from Theia stayed largely intact as they sifted down to the base of the mantle, like the colored masses of paraffin wax in a turned-off lava lamp. Had the lower mantle been hotter (that is, if it had received more energy from the impact), it would have mixed more thoroughly with the iron-rich material, like the colors in a stirred pot of paints.

The next steps are to examine how the early presence of Theia's heterogeneous material deep within the earth might have influenced our planet's interior processes, such as plate tectonics.

"A logical consequence of the idea that the LLVPs are remnants of Theia is that they are very ancient," Asimow says. "It makes sense, therefore, to investigate next what consequences they had for Earth's earliest evolution, such as the onset of subduction before conditions were suitable for modern-style plate tectonics, the formation of the first continents, and the origin of the very oldest surviving terrestrial minerals."

The paper is titled "Moon-forming impactor as a source of Earth's basal mantle anomalies." Qian Yuan is the first author. In addition to Yuan and Asimow, the additional Caltech coauthor is Yoshinori Miyazaki, Stanback Postdoctoral Scholar Research Associate in Comparative Planetary Evolution. Additional coauthors are Mingming Li, Steven Desch, and Edward Garnero (PhD '94) of Arizona State University (ASU); Byeongkwan Ko of ASU and Michigan State University; Hongping Deng of the Chinese Academy of Sciences; Travis Gabriel of the U.S. Geological Survey; Jacob Kegerreis of NASA’s Ames Research Center; and Vincent Eke of Durham University. Funding was provided by the National Science Foundation, the O.K. Earl Postdoctoral Fellowship at Caltech, the U.S. Geological Survey, NASA, and the Caltech Center for Comparative Planetary Evolution.

[kreuzaderny]

ESA’s Jupiter Icy Moons Explorer, Juice, will make detailed observations of the giant gas planet and its three large ocean-bearing moons – Ganymede, Callisto and Europa – with a suite of remote sensing, geophysical and in situ instruments. The mission will characterise these moons as both planetary objects and possible habitats, explore Jupiter’s complex environment in depth, and study the wider Jupiter system as an archetype for gas giants across the Universe.

[deimos-awaits]

Regarding the Irongsong Chapter Homeworld of Astraea

“Astraea is a world of extremes. It is divided down the middle by the remnants of extreme tectonic activity that has resulted in vast mountain ranges down the planet's prime meridian that pierce the atmosphere. According to the Mechanicus’s Geophysical Survey all tectonic activity of that magnitude has long since ceased. The mountain range created by this survey, named the Emperor's Spine by locals, is made out of solid granite. This has resulted in an interesting quirk that Astraea has for all practical purposes two separate atmospheres as no gas can pass between the two sides. It also means that any travel between the two either needs to occur through carefully sealed and regulated tunnel systems in the mountains or short range extratmospheric travel.

The Ironsong Chapter and previous planetary governors have long made use of this advantageous difference in atmosphere to diversify the planet's activities between that a typical administrum scribe might otherwise assign a planet of roughly the same size as Holy Terra.

The two halves of the Astraea each have a vastly different economic base, now given a nickname by local inhabitants after part of the Ironsong Chapter name. The Iron half of Astraea is a virtual forgeworld, filled to the brim with the industrial ordered base that produces much of the raw materials needed to support the heavy mechanization focus of the Ironsong Chapter as well as the Song section of the planet. It is hard to breathe on this half of the planet without a respirator or long adaptation through time living in the toxic smog. The main administrative hub of this half of the planet is a hive settlent known as Archmidopolis. The fires and smog of industry never ceases day or night to supply either paradise or the unending war of the Ironsong Chapter upon our unholy foes.

The Song half of Astraea is a paradise world in miniature. The old planetary governors of Astraea used to rule from here. Vast manicured forests and placid fresh water oceans reminiscent of Grecea on Old Earth before the Med was boiled away. On this half the planet fresh fruits and I'm particular olives and grapes are grown in carefully controlled and organized orchards. The inhabitants of this half of the world are able to explore the arts and what arcane arts the Mechanicus sponsors in vast symposiums. The old capital city of Novos Athoni is a sprawling city of wide boulevards and fresh air. It was a beautiful site after having been a child raised in Archmidopolis.

As part of the Ironsong Chapter traditions, aspirations are always suggested two at a time one for the Iron half of Astraea and one from the Song half. Further as part of the chapter's dedication to balance between both the industrial beauty of our mechanicus allies, and the children of Song, aspirants must be inducted into full membership of the chapter two at a time, both one from each half. Whether as forgerat, as we were called, or fop, each man and woman of the chapter is important. For readers unaware, the geneseed of the Ironsong Chapter has a unique trait that allows it to take hold in both men and women, however a part of the process random secondary sex traits of either sex have occasionally been known to appear on aspirants regardless of their original sex. Any further comments about primary traits changing are pure speculation and not supported by any evidence.

The chapter's fortress monstary can be found in a section of vast holowed out caverns in the Emperor's Spine connecting both half of the planet."

-From the collected works of Artificer Siderénia Teleiótita, Chapter Master of the Ironsong

[geoledgy]

Think of any science and there will be a geology subsection of it. We know there's geochemistry, geophysics, geoastronomy/planetary geology, and geobiology, let's go further. Medical? Yea there's geo-health. Psychology? Yeah there's geo-psychology. Criminology? Yeah there's geo-forensics. You can tack on geo- in front of everything and it'll be a thing. There is nothing geology cannot do!!!!!!

[mindblowingscience]

NASA's InSight mission to Mars helped scientists map out Mars' internal structure, including the size and composition of its core, and provided general hints about its tumultuous formation. But findings from a new paper, titled "Geophysical evidence for an enriched molten silicate layer above Mars' core," published in the journal Nature could lead to reanalysis of that data. An international team of researchers discovered the presence of a molten silicate layer overlying Mars' metallic core—providing new insights into how Mars formed, evolved and became the barren planet it is today. Published on October 25, 2023, the team's paper details the use of seismic data to locate and identify a thin layer of molten silicates (rock-forming minerals that make up the crust and mantle of Mars and Earth) lying between the Martian mantle and core. With the discovery of this molten layer, the researchers determined that Mars' core is both denser and smaller than previous estimates, a conclusion that better aligns with other geophysical data and analysis of Martian meteorites.

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[spacenutspod]

5 Min Read Why is Methane Seeping on Mars? NASA Scientists Have New Ideas Filled with briny lakes, the Quisquiro salt flat in South America’s Altiplano region represents the kind of landscape that scientists think may have existed in Gale Crater on Mars, which NASA’s Curiosity Rover is exploring. Credits: Maksym Bocharov The most surprising revelation from NASA’s Curiosity Mars Rover — that methane is seeping from the surface of Gale Crater — has scientists scratching their heads. Living creatures produce most of the methane on Earth. But scientists haven’t found convincing signs of current or ancient life on Mars, and thus didn’t expect to find methane there. Yet, the portable chemistry lab aboard Curiosity, known as SAM, or Sample Analysis at Mars, has continually sniffed out traces of the gas near the surface of Gale Crater, the only place on the surface of Mars where methane has been detected thus far. Its likely source, scientists assume, are geological mechanisms that involve water and rocks deep underground. If that were the whole story, things would be easy. However, SAM has found that methane behaves in unexpected ways in Gale Crater. It appears at night and disappears during the day. It fluctuates seasonally, and sometimes spikes to levels 40 times higher than usual. Surprisingly, the methane also isn’t accumulating in the atmosphere: ESA’s (the European Space Agency) ExoMars Trace Gas Orbiter, sent to Mars specifically to study the gas in the atmosphere, has detected no methane. Why do some science instruments detect methane on the Red Planet while others don’t? “It’s a story with a lot of plot twists,” said Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California, which leads Curiosity’s mission. Methane keeps Mars scientists busy with lab work and computer modeling projects that aim to explain why the gas behaves strangely and is detected only in Gale Crater. A NASA research group recently shared an interesting proposal. Reporting in a March paper in the Journal of Geophysical Research: Planets, the group suggested that methane — no matter how it’s produced — could be sealed under solidified salt that might form in Martian regolith, which is “soil” made of broken rock and dust. When temperature rises during warmer seasons or times of day, weakening the seal, the methane could seep out. Led by Alexander Pavlov, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the researchers suggest the gas also can erupt in puffs when seals crack under the pressure of, say, a rover the size of a small SUV driving over it. The team’s hypothesis may help explain why methane is detected only in Gale Crater, Pavlov said, given that’s it’s one of two places on Mars where a robot is roving and drilling the surface. (The other is Jezero Crater, where NASA’s Perseverance rover is working, though that rover doesn’t have a methane-detecting instrument.) Pavlov traces the origin of this hypothesis to an unrelated experiment he led in 2017, which involved growing microorganisms in a simulated Martian permafrost (frozen soil) infused with salt, as much of Martian permafrost is. Pavlov and his colleagues tested whether bacteria known as halophiles, which live in saltwater lakes and other salt-rich environments on Earth, could thrive in similar conditions on Mars. The microbe-growing results proved inconclusive, he said, but the researchers noticed something unexpected: The top layer of soil formed a salt crust as salty ice sublimated, turning from a solid to a gas and leaving the salt behind. Permafrost on Mars and Earth “We didn’t think much of it at the moment,” Pavlov said, but he remembered the soil crust in 2019, when SAM’s tunable laser spectrometer detected a methane burst no one could explain. “That’s when it clicked in my mind,” Pavlov said. And that’s when he and a team began testing the conditions that could form and crack hardened salt seals. Pavlov’s team tested five samples of permafrost infused with varying concentrations of a salt called perchlorate that’s widespread on Mars. (There’s likely no permafrost in Gale Crater today, but the seals could have formed long ago when Gale was colder and icier.) The scientists exposed each sample to different temperatures and air pressure inside a Mars simulation chamber at NASA Goddard. Periodically, Pavlov’s team injected neon, a methane analog, underneath the soil sample and measured the gas pressure below and above it. Higher pressure beneath the sample implied the gas was trapped. Ultimately, a seal formed under Mars-like conditions within three to 13 days only in samples with 5% to 10% perchlorate concentration. This is a sample of mock Martian regolith, which is “soil” made of broken rock and dust. It’s one of five samples that scientists infused with varying concentrations of a salt called perchlorate that’s widespread on Mars. They exposed each sample to Mars-like conditions in the Mars simulation chamber at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The brittle clumps in the sample above show that a seal of salt did not form in this sample because the concentration of salt was too low. NASA/Alexander Pavlov This image is of another sample of mock Martian “soil” after it was removed from the Mars simulation chamber. The surface is sealed with a solid crust of salt. Alexander Pavlov and his team found that a seal formed after a sample spent three to 13 days under Mars-like conditions, and only if it had 5% to 10% perchlorate salt concentration. The color is lighter in the center where the sample was scratched with a metal pick. The light color indicates a drier soil underneath the top layer, which absorbed moisture from the air as soon as the sample was removed from the simulation chamber, turning brown. NASA/Alexander Pavlov That’s a much higher salt concentration than Curiosity has measured in Gale Crater. But regolith there is rich in a different type of salt minerals called sulfates, which Pavlov’s team wants to test next to see if they can also form seals. Curiosity rover has arrived at a region believed to have formed as Mars’ climate was drying. Improving our understanding of methane generation and destruction processes on Mars is a key recommendation from the 2022 NASA Planetary Mission Senior Review, and theoretical work like Pavlov’s is critical to this effort. However, scientists say they also need more consistent methane measurements. SAM sniffs for methane only several times a year because it is otherwise busy doing its primary job of drilling samples from the surface and analyzing their chemical makeup. In 2018, NASA announced that the Sample Analysis at Mars chemistry lab aboard the Curiosity Rover discovered ancient organic molecules that had been preserved in rocks for billions of years. Findings like this one help scientists understand the habitability of early Mars and pave the way for future missions to the Red Planet.Credit: NASA’s Goddard Space Flight CenterDownload this video in HD formats from NASA Goddard’s Scientific Visualization Studio “Methane experiments are resource intensive, so we have to be very strategic when we decide to do them,” said Goddard’s Charles Malespin, principal investigator for SAM. Yet, to test how often methane levels spike, for instance, would require a new generation of surface instruments that measure methane continuously from many locations across Mars, scientists say. “Some of the methane work will have to be left to future surface spacecraft that are more focused on answering these specific questions,” Vasavada said. By Lonnie ShekhtmanNASA’s Goddard Space Flight Center, Greenbelt, Md. Share Details Last Updated Apr 22, 2024 Contact Lonnie Shekhtman lonnie.shekhtman@nasa.gov Location Goddard Space Flight Center Related Terms Curiosity (Rover) Goddard Space Flight Center Mars Mars Exploration Program Mars Science Laboratory (MSL) Missions NASA Directorates Planetary Science Division Science Mission Directorate The Solar System

[fuckyeahfluiddynamics]

Fire in Ice

This false-color satellite image of Malaspina Glacier (Sít’ Tlein) is a riot of color. Composed of coastal/aerosol, near infrared, and shortwave infrared bands from Landsat 9, the colors highlight features otherwise hard to identify.  (Image credit: W. Liang; via NASA Earth Observatory) Read the full article

[female-malice]

Dear Anthropocene Working Group:

It is with mixed emotions that I am sending this letter to resign from the Anthropocene Working Group. I’ve been a member since AWG began in 2009 and many of my most treasured experiences as a scholar have unfolded with AWG. Over most of the past 14 years, AWG has exemplified the kind of scholarly community that encourages exploration of new ideas and evidence and the spirit of open collegial debate needed to build strong science. Even though, as an ecologist, my professional perspectives and contributions have often differed from the core views of the group, I’ve generally found these to be welcome and productive. For all of these reasons, I feel sadness in resigning.

Nevertheless I must resign, for two reasons. The first is that things have changed within the group, as exemplified by the increasingly corrosive nature of discussions surrounding two recent resignations. AWG has become so focused on promoting a single narrow definition of the Anthropocene that there is no longer room for dissent or for a broader perspective within the group. This narrowing of perspective began to emerge years ago, with the 2016 vote deciding that only evidence supporting a mid-20th century start date would be considered in Anthropocene definition. Looking back, I probably should have resigned at that time. But recent efforts to promote the group’s final GSSP and site proposal have now established beyond doubt that there is no longer any place for broader perspectives on Anthropocene definition within AWG. The group exists only to promote one single narrow perspective, and differing views are no longer acceptable. I clearly no longer have any useful role in the group.

Second, it is no longer possible to avoid the reality that narrowly defining the Anthropocene in the way AWG has chosen to do has become more than a scholarly concern. The AWG’s choice to systematically ignore overwhelming evidence of Earth’s long-term anthropogenic transformation is not just bad science, it’s bad for public understanding and action on global change. This, at a time when broader cooperation to address these grave societal challenges is more critical than ever.

To define the Anthropocene as a shallow band of sediment in a single lake is an esoteric academic matter. But dividing Earth’s human transformation into two parts, pre- and post- 1950, does real damage by denying the deeper history and the ultimate causes of Earth’s unfolding social-environmental crisis. Are the planetary changes wrought by industrial and colonial nations before 1950 not significant enough to transform the planet? The political ramifications of such a misleading and scientifically inaccurate portrayal are clearly profound and regressive. Perhaps AWG’s break in Earth history will simply be ignored outside stratigraphy. But this is undoubtedly neither AWG’s goal, nor is it the way AWG’s narrative is being interpreted across the public media.

I was first inspired to work on the Anthropocene as a geological concept in 2008, in response to the GSA Today article led by Jan and the exciting scientific and societal discussions surrounding it. Soon after, Jan and I organized a session together and met in person at the American Geophysical Union meeting in San Francisco in December 2008. I was then asked to join AWG and gladly accepted. Many good years of scientific collaboration followed.

As a scholar who has actively worked within a group now promoting a misleading and regressive perspective on Earth’s transformation by human societies, I feel obligated to respond. First, by formally ending my association with the group, and in the long term, by doing my best to counteract the damage created by this misleading perspective based on the best available science.

I have many fond memories and I retain my respect and admiration for all my colleagues in AWG. I remain hopeful that the Anthropocene as a concept will continue to inspire efforts to understand and more effectively guide societal interactions with our only planet. I no longer believe that the AWG is helping to achieve this and is increasingly actively accomplishing the opposite.

I therefore wish to formally resign from the Anthropocene Working Group.

Sincerely, Erle Ellis

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Geophysical Alert Message wwv

:Issued: 2024 Mar 11 0905 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

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# Geophysical Alert Message

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Solar-terrestrial indices for 10 March follow.

Solar flux 127 and estimated planetary A-index 6.

The estimated planetary K-index at 0900 UTC on 11 March was 2.33.

Space weather for the past 24 hours has been moderate.

Radio blackouts reaching the R2 level occurred.

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