Top 5 planets!!!

😍 Thanks for the fun ask, aquaticpal! I'm going to modify this slightly because I already put Earth as my favorite celestial body of all in my previous post about that. I'll do my top 5 planets excluding Earth so I don't repeat myself.

Counting down!

5. Pluto

If you've been paying attention to some astronomy in the last decade or two, you probably know Pluto isn't being called a "Planet" officially anymore.

...I don't care.

The image above shows Pluto (lower right) and its large moon Charon (upper left) as imaged by the New Horizons probe. The frozen heart-shaped feature on Pluto's icy surface melted my own heart (and I wasn't alone).

The whole hullabaloo about Pluto not being a planet is just semantics. It's a celestial body with enough gravity to be round, and it orbits the Sun. I'll count it.

So, why does it make it to my favorites list?

Pluto is geologically active (like Earth - it has its own geology happening on its surface, like volcanoes, tectonics, and erosion), a reality many did not expect until the New Horizons spacecraft started returning close-up pictures of this distant world. The smoothness of Pluto's signature heart-shaped feature (particularly the left side) is a dead giveaway that geological activity is happening on its surface. Worlds where there's no active geology are covered in craters everywhere, not just in some places, and the more recently it's been active the fewer craters there are per area. So.... Pluto is a 'living world' with enough energy inside it to make its insides move.

Cool.

It might be the close orbit of its moon Charon causing it - the shifting gravity stirring up Pluto's innards (and Charon's!), causing friction, and thus heat.

Either way, there's enough geological activity on Pluto to create these gorgeous mountains:

It has seasons during which the frozen nitrogen at its surface becomes warm enough to create mists - nitrogen fog. Imagine if Earth were cold enough that our very air would turn into blocks of ice that create white vapor - kind of like dry ice does.

Pluto is fascinating: a world that defied our expectations. I love it.

4. Trappist-1f

This artist's rendition shows what exoplanet Trappist-1f might look like if it has liquid surface water. It's too small and too far away to get an actual picture, but the evidence shows this planet exists in the habitable zone of its star.

The Trappist-1 star system lies about 40 light-years from Earth (very nearby in the grand scheme of things). Within it, seven planets orbit a small, cool red dwarf star (that's Trappist-1). The planets don't have 'given' names like Pluto or Earth. They're assigned letters b-h, with b the closest and h the furthest from the star. Planets e, f, and g are all in the star's habitable zone, which means they could have liquid water on their surfaces.

So, why did I specifically pick Trappist-1f? It's the planet most perfectly centered in the habitable zone, and its properties are all quite similar to Earth's: it's radius, mass, density, and surface gravity. In order to be hospitable to life as we know it, it's important for a planet to be able to keep itself warm (not just from the light from its Sun - it needs its own, internal heat source, too, to stay geologically active and produce a protective magnetic field - this keeps the atmosphere stable rather than letting its sun's radiative wind blow lots of it away, and also protects life on its surface from that same radiation that would split our complex organic components apart).

Trappist-1f is extremely close to its star, but the star is very cool, so it's unlikely to be very hot. It only takes the planet 9.2 days to orbit the star once. (Yes, you read that right - Trappist-1f's year is only 9.2 Earth days long! If you lived there, I bet you'd find some other way to celebrate birthdays. You'd be having a party just about every week).

I'm all for finding planets that might have water, and therefore might have life... or might be good for us to live on, some day.

The other cool thing about its place is ALL the planets are quite close to the star, so they'd appear huge in the sky regardless of which of the other planets you were standing on. This is a cool, artistic interpretation of that:

3. Proxima Centauri b

Speaking of places where we might be able to live...

...welcome to Proxima Centauri b - the nearest exoplanet to Earth... and also in its star's habitable zone.

Proxima Centauri b is a small, cool, red dwarf star part of the Alpha Centauri system, a triple-star system consisting of two brighter stars (Alpha Centauri A and Alpha Centauri B, both similar to the Sun) which are close to each other, and the cool red dwarf Proxima Centauri b, still orbiting the others but much farther away.

And around that small cool dwarf star is a planet not too different from Earth.

I can't stress enough how incredible that is.

This is the very nearest star system to our own, only four light-years from here.

And in it, there is already a possible stepping stone for us to move outward into the Cosmos. And not just a stepping stone, but possibly somewhere habitable.

Wow.

We need to learn more about this planet. It may or may not be hospitable. It may or may not have an atmosphere. We just don't know yet. But it's hope. It's one of many signs that the galaxy is absolutely littered with planets, and there may be many worlds like ours.

2. Jupiter

This image taken by the Juno Probe shows a lot of what makes Jupiter awe-inspiring: roiling masses of hydrogen and helium gas with traces of methane, ammonia, silica, and sulfur creating myriad colors in its clouds, storms which could swallow several Earths whole, and of course its huge mass which make it a gravitational well, holding on to a minimum of 80 moons. The huge shadow of its moon Ganymede is visible on the left-hand side in the picture.

First of all, Jupiter is, quite simply, beautiful. Just look at it.

All those colors, the swirls, its absurdly fast rotation (a 10-hour period!) pulling its clouds out into these thin bands. It's so striking. Add to that the shadows of its many moons crossing its surface, and you have a recipe for endless visual fascination.

But that alone isn't enough to make it one of my favorites.

I love Jupiter because it protects us.

Jupiter's gravity is so strong it tends to divert and even capture many objects which hurtle inward toward the Earth and the other inner planets, meaning fewer things actually hit the Earth than they otherwise would. Jupiter is the batter at plate, and we're the catcher. We really don't want any of those strikes thrown to cross the plate.

Thank-you, Jupiter.

I also love Jupiter because it provides a home for other worlds - the moons Europa and Ganymede in particular - which might be places to find life. Europa's the far more likely of the two, but I won't belabor that point. Suffice to say, Jupiter's gravity provides the energy that keeps Europa active, with an underground ocean, potentially a safe haven for organic life. I hope to live long enough to find out.

Mars

My pattern by this point is probably clear. I'm rooting for life and for places we could move to one day. The absolute tippy-top of that list is Mars.

This image shows many features of Mars which show past geological activity and the outline of what once was the shore of a truly vast ocean.

The more missions we send to Mars, the more likely we realize it is that Mars could once have had life on its surface, and could even harbor it right now below ground.

You can see the outlines of several ancient volcanoes in the left-hand side of this picture, and a truly massive TEAR in the planet's surface front-and-center. That thing is as long as the entire continent of North America. There are plenty of craters, which means it hasn't been geologically active ( at least not much) in a long time, but the signs of past activity on its surface are clear. It has dry riverbeds. Dry ocean beds. Dry lake beds. Dry glacial footprints. Ancient volcanoes. The robots we've landed to explore the surface have found clear, smoking-gun type evidence of past running water in these places (clay is a big one, and there's hematite, too), and the basic components for life are there. The one thing we haven't found yet is life itself.

We now understand Mars lost its once-watery exterior thanks to it being too small. Its interior cooled off, slowing and nearly stopping geological activity entirely, and stopping Mars' rotation from creating a magnetic dynamo like Earth has - so Mars lost its protective magnetic bubble stopping the Sun's radiation from striking its atmosphere and surface. The Sun basically blew Mars' air away into space, and irradiated its top soil. So.. the top two inches of the soil are entirely barren.

But RIGHT below that.... we have found water ice. And below that... there are underground rivers. Sinkholes and orbital measurements of density have shown that.

We might be able to send people there and have them survive underground. We'd need some way to deal with Mars' lost protective bubble at some point if we wanted to make the surface habitable. Dome cities might be okay, though those always creep me out. I just picture something puncturing it and causing problems. But.... it's so close. And it might have life, or once had it.

I have so much to say about all these places, but if I keep going this will just become interminable. So... I'll stop. Here's my list. I hope you enjoy!

Flip it and reverse it: How the moon ‘turned itself inside out’

A study suggests that dense minerals (grey), left over from the Moon’s early history, are likely responsible for the satellite’s odd gravity.

Some 4.5 billion years ago, a small planet collided with Earth. This explosive impact, sometimes called the “big whack,” launched bits of molten debris into space. They eventually cooled and coalesced to form our Moon. This hypothesis is widely accepted among scientists, but many details remain fuzzy, including exactly how the lunar interior evolved, or why its current geology is so “lopsided.” Now, scientists may have put this long-standing mystery to rest. Using a combination of rock samples, satellite data, and computer simulations, researchers demonstrate how magma oceans on the surface of the young Moon crystallized into dense minerals like ilmenite. Because this layer was so heavy, huge slabs sank into the lunar interior, melted into the churning mantle, and eventually resurfaced as titanium-rich lava flows. “Our moon literally turned itself inside out,” planetary scientist and study co-author Jeff Andrews-Hanna said in a press release...

Read more: https://www.science.org/content/article/scienceadviser-vaccine-mrsa-flagging-bacterial-proteins-could-make-it-possible

(@askpokepals) Skarla: "Heya, I just thought aboot stopping by to say hello to all the wonderful mon in this university, and ye got quite the university alright! How many departments do ye have?" @ Marcin

" Theres a huge range of programs here so it’d be a lot of work naming them all. I can give a bit of a brief rundown though…"

"Harmonia over the years became more of a technology oriented school. There, we've got the engineering department, which includes all sorts of different branches like software, computer, mechanical, chemical, all the like."

"During the human era, Harmonia was actually most known for its biology programs! So there's a lot of departments within biology, there's anatomty, cellular biology, type studies, neuroscience, evolution science...and tons of others."

"See thats already starting to pile up. Theres the other sciences, like chemistry, mathematics, physics and computer science. We’ve even got some more specialized programs like earth and planetary sciences, geology, atmospheric and ocean sciences. Oh, and not to mention everything that's in the faculty of arts. You know, stuff like linguistics, history, political science, and the like. The school also offers programs in education, battle studies, music, law, business, theres probably a whole lot more than that too.”

"Theres just so much to discover and learn about, its always so hard for students to just pick something they like right off the bat. Haha. I dont blame em!"

[ @megamannickblog / @askpokepals ]

Pressure required to launch a rock from Mars into space much lower than thought, discovers study In August 1865, a 10-pound rock fell from space to Earth, landing with a bang in the remote village of Sherghati, India. After being recovered by witnesses to the event, the stone passed into the possession of a local British magistrate who endeavored to identify the source of the strange object. After more than a century of studying the meteorite fragments—so-called shergottites—researchers in the 1980s finally determined its alien origins: our neighboring planet, Mars. Until humans are able to bring back samples from Mars, the only pieces of the Red Planet found on Earth are Martian meteorites such as the shergottites. The journey for these little Martian travelers has been violent: for Mars rocks to get to Earth, they must have been ejected from the Red Planet's surface with enough force to escape Martian gravity. This ejection was likely due to a large impact on Mars. The rocks withstood the massive temperatures and pressures of this impact and flew through the vacuum of space, eventually crash-landing on our own planet. For decades, scientists have worked on modeling the kind of Martian impact events that send bits of the Red Planet to Earth. Now, researchers at Caltech and the Jet Propulsion Laboratory (JPL), which Caltech manages for NASA, have conducted experiments to simulate the so-called "shock pressure" experienced by Martian rocks. They have found that the pressure required to launch a rock from Mars into space is much lower than originally thought. The research was conducted in the laboratory of Paul Asimow, the Eleanor and John R. McMillan Professor of Geology and Geochemistry. The study is described in a paper appearing in the journal Science Advances on May 3 and is a collaboration with JPL. In the new study, led by Caltech staff scientist Jinping Hu, the team conducted experiments to smash plagioclase-containing rocks from Earth and observe how the mineral transforms under pressure. The team developed a more accurate method to simulate Martian impacts in shock-recovery experiments, utilizing a powerful "gun" to blast rocks with projectiles traveling over five times the speed of sound. Previous shock-pressure experiments required reverberating shock waves through a steel chamber, which gives an inaccurate picture of what happens during an impact event on Mars. "We're not on Mars, so we can't watch a meteorite strike in person," says Yang Liu, a planetary scientist at JPL and a co-author on the study. "But we can recreate a similar kind of impact in a lab setting. By doing so, we found it takes much less pressure to launch a Mars meteorite than we thought." Previous experiments had shown that plagioclase turns into maskelynite at a shock pressure of 30 gigapascals (GPa), which is 300,000 times the atmospheric pressure one experiences at sea level, or 1,000 times the pressure a submersible comes into contact with while diving beneath 3 kilometers of ocean water. This new study shows that the transition actually happens at around 20 GPa—a significant difference from previous experiments. In particular, the new pressure threshold is consistent with evidence from other high-pressure minerals in these meteorites indicating that their shock pressures must have been less than 30 GPa. Nine out of the 10 high-pressure minerals found in Martian meteorites were discovered at Caltech in studies led by mineralogist Chi Ma, Caltech's director of analytical facilities, and a co-author of the study. "It has been a significant challenge to model an impact that can launch intact rocks from Mars while shocking them to 30 GPa," Asimow says. "In this context, the difference between 30 GPa and 20 GPa is significant. The more accurately we can characterize the shock pressures experienced by a meteorite, the more likely it becomes that we can identify the impact crater on Mars from which it originated." TOP IMAGE....A Martian meteorite, designated Northwest Africa (NWA) 7034 and nicknamed "Black Beauty," weighing approximately 11 ounces. Caltech researchers have now discovered that the shock pressure necessary to launch rocks from Mars' surface is less than previously believed. This meteorite itself was not used in the new study. Credit: NASA LOWER IMAGE....Two impact-cratered target assemblies. The overall chamber is made of stainless steel. Rock samples are placed in the center of the chamber. The black stains are from decomposed plastic sabot and O-rings of the projectile. Credit: Jinping Hu

I am torn as to whether or not I want to reply to the Pluto discourse thread but I think I will not.

Do I emotionally consider Pluto a planet? Yes because that is the information that I internalized as a child and I am oddly fond of it especially now that we have better pictues of it. Also a piece of media that was (and still is) very important to me as a teenager has Pluto as a planet as part of its basic worldbuilding structure (yes it's Sailor Moon*).

But the thing is that I can't ignore that Eris, Sedna, Makemake, etc. exist. I also very fond of these trans-neptunian objects. So logically Pluto belongs with them, we just didn't know they were there until very recently. I don't think the re-classification of Pluto from planet to dwarf planet was an easy decision to make but honestly it may have been a necessary decision to make the study of our solar system make more sense.

And I just found this paper that makes things even more complicated in my head because it argues that the definition of a planet by orbit is not the appropriate way to define a planet and planets should be defined by the geology of an object. It claims that this should expand the definition to include moons. I think it argues that the IAU rushed it's decision and that it has embraced the folk taxonomy for planets.

Also it brings up how the word fruit means different things in different contexts. I'm gonna have to sit down and read this and chew on it a bit.

*Sailor Moon is a weird thing because since there is a Sailor Guardian for the Earth's moon, it is clear that an object does not have to be a planet per se to have a Sailor Guardian. So the redefinition of Pluto to dwarf planet does not actually change Sailor Pluto's status because as long as a celestial object has a Sailor Crystal, it can have a Sailor Guardian. Additionally, in the Sailor Moon manga and in the Sailor Moon Eternal movies, it is revealed there are Sailor Soldiers for Ceres, Vesta, Juno and Pallas, which at the time were not defined as planets.

Also as additional trans-neptunian objects were discovered, I started creating fan made Sailor Guardians for them and I really enjoyed it. I took a lot of my inspiration from the fact that Sailor Pluto was the solitary guardian of the Time Gate and made them also solitary guardians of various important to the fabric of the universe things. Because that's what made sense.

A mineral produced by plate tectonics has a global cooling effect, study finds

New Post has been published on https://thedigitalinsider.com/a-mineral-produced-by-plate-tectonics-has-a-global-cooling-effect-study-finds/

A mineral produced by plate tectonics has a global cooling effect, study finds

MIT geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon.

Now, the MIT team has shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

These clays can be found in certain tectonically active regions today, and the scientists believe that smectite continues to sequester carbon, providing a natural, albeit slow-acting, buffer against humans’ climate-warming activities.

“The influence of these unassuming clay minerals has wide-ranging implications for the habitability of planets,” says Joshua Murray, a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “There may even be a modern application for these clays in offsetting some of the carbon that humanity has placed into the atmosphere.”

Murray and Oliver Jagoutz, professor of geology at MIT, have published their findings today in Nature Geoscience.

A clear and present clay

The new study follows up on the team’s previous work, which showed that each of the Earth’s major ice ages was likely triggered by a tectonic event in the tropics. The researchers found that each of these tectonic events exposed ocean rocks called ophiolites to the atmosphere. They put forth the idea that, when a tectonic collision occurs in a tropical region, ophiolites can undergo certain weathering effects, such as exposure to wind, rain, and chemical interactions, that transform the rocks into various minerals, including clays.

“Those clay minerals, depending on the kinds you create, influence the climate in different ways,” Murray explains.

At the time, it was unclear which minerals could come out of this weathering effect, and whether and how these minerals could directly contribute to cooling the planet. So, while it appeared there was a link between plate tectonics and ice ages, the exact mechanism by which one could trigger the other was still in question.

With the new study, the team looked to see whether their proposed tectonic tropical weathering process would produce carbon-trapping minerals, and in quantities that would be sufficient to trigger a global ice age.

The team first looked through the geologic literature and compiled data on the ways in which major magmatic minerals weather over time, and on the types of clay minerals this weathering can produce. They then worked these measurements into a weathering simulation of different rock types that are known to be exposed in tectonic collisions.

“Then we look at what happens to these rock types when they break down due to weathering and the influence of a tropical environment, and what minerals form as a result,” Jagoutz says.

Next, they plugged each weathered, “end-product” mineral into a simulation of the Earth’s carbon cycle to see what effect a given mineral might have, either in interacting with organic carbon, such as bits of dead organisms, or with inorganic, in the form of carbon dioxide in the atmosphere.

From these analyses, one mineral had a clear presence and effect: smectite. Not only was the clay a naturally weathered product of tropical tectonics, it was also highly effective at trapping organic carbon. In theory, smectite seemed like a solid connection between tectonics and ice ages.

But were enough of the clays actually present to trigger the previous four ice ages? Ideally, researchers should confirm this by finding smectite in ancient rock layers dating back to each global cooling period.

“Unfortunately, as clays are buried by other sediments, they get cooked a bit, so we can’t measure them directly,” Murray says. “But we can look for their fingerprints.”

A slow build

The team reasoned that, as smectites are a product of ophiolites, these ocean rocks also bear characteristic elements such as nickel and chromium, which would be preserved in ancient sediments. If smectites were present in the past, nickel and chromium should be as well.

To test this idea, the team looked through a database containing thousands of oceanic sedimentary rocks that were deposited over the last 500 million years. Over this time period, the Earth experienced four separate ice ages. Looking at rocks around each of these periods, the researchers observed large spikes of nickel and chromium, and inferred from this that smectite must also have been present.

By their estimates, the clay mineral could have increased the preservation of organic carbon by less than one-tenth of a percent. In absolute terms, this is a miniscule amount. But over millions of years, they calculated that the clay’s accumulated, sequestered carbon was enough to trigger each of the four major ice ages.

“We found that you really don’t need much of this material to have a huge effect on the climate,” Jagoutz says.

“These clays also have probably contributed some of the Earth’s cooling in the last 3 to 5 million years, before humans got involved,” Murray adds. “In the absence of humans, these clays are probably making a difference to the climate. It’s just such a slow process.”

“Jagoutz and Murray’s work is a nice demonstration of how important it is to consider all biotic and physical components of the global carbon cycle,” says Lee Kump, a professor of geosciences at Penn State University, who was not involved with the study. “Feedbacks among all these components control atmospheric greenhouse gas concentrations on all time scales, from the annual rise and fall of atmospheric carbon dioxide levels to the swings from icehouse to greenhouse over millions of years.”

Could smectites be harnessed intentionally to further bring down the world’s carbon emissions? Murray sees some potential, for instance to shore up carbon reservoirs such as regions of permafrost. Warming temperatures are predicted to melt permafrost and expose long-buried organic carbon. If smectites could be applied to these regions, the clays could prevent this exposed carbon from escaping into and further warming the atmosphere.

“If you want to understand how nature works, you have to understand it on the mineral and grain scale,” Jagoutz says. “And this is also the way forward for us to find solutions for this climatic catastrophe. If you study these natural processes, there’s a good chance you will stumble on something that will be actually useful.”

This research was funded, in part, by the National Science Foundation.

Well we got the Artifact. It was a bit of a shit show. We snuck into the mine, but there were a bunch of Shaw gang holed up in there. Nice little firefight, and I ended up using all of my med packs.

Got the Artifact and, just like before... visions of grav jumping, glyphs (different this time. Does each Artifact have it's own?), music, and that feel of rushing through space. Not gonna lie, it feels good.

Well Shaw herself met us as we tried to sneak out of the cave. I managed to jump up to the cliffs (the cave was in a kind of rocky ravine) and snipe out three or four.

Then some local carnivores moved in. They're called Asha. Big, mean, and stink to high heaven. So Sam and I are running all over shooting Shaw gang and Asha.

Obviously we succeeded and I made Sam wait while I did a quick run through of the entire site. Gathered a bunch of guns to resell, ammo, some med kits, nothing of too much value.

The hideout was actually in sight of Akila City, can you believe it? We headed back and I sold what I could. Saw a sweet Sidewinder for sale, but couldn't afford it after the ship upgrades I did.

Sam and I got on well together. The man has no small talk whatsoever, but I appreciate that. He certainly had my back during the action, and he was supportive when I negotiated with the gang at the bank. I wouldn't mind having him as a second during planetary surveys. He's got a geology background as well!

We'll take the Artifact back to the Lodge and I'll talk to Sam about becoming a permanent part of my crew.

The first palaeontologist on Mars

(Image: Artist’s impression of NASA’s Perseverance rover on Mars)

Today NASA’s Perseverance rover landed on Mars. I don’t usually talk astronomy on this blog, but this time it’s relevant because—as you might have read—Perseverance is more or less the first palaeontologist on Mars!

Let me explain.

(Image: Satellite topography map of Jezero Crater, the site where Perseverance landed)

The site where Perseverance is landing, Jezero Crater, is a meteor impact crater near Mars’s Equator (say that 10 times fast!). It has evidence of a delta—the geomorphic feature that occurs when running water enters a large body of water. Orbital analyses also suggest it’s filled with carbonate rock—the kind that tend to deposit at the bottom of bodies of water.

Jezero Crater is not filled with water today. But the evidence strongly suggests it once was. If we’re going to find evidence of life on Mars, this is a good place to start looking.

Microbial fossils

When you think of fossils, most people think of giant T. rex skeletons, or frozen woolly mammoths, or neanderthal skulls. Maybe you’ve been around the block a bit, and you think about corals, or plant fossils, or tiny fossil shells. But some of the most common and important fossils on Earth are even tinier. Microbial fossils are commonly made by bacteria, archaea, and the like.

(Image: A cross-section of a stromatolite fossil, showing the multiple layers)

Some of the earliest fossils on earth are called stromatolites. They occur when bacterial colonies grow together in a mat—then, over time, sediment deposits over the colony, and the bacteria form another layer on top of the previous layer. Over time, many layers can be formed.

(Image: Helium Ion Microscopy image of iron oxide filaments formed by bacteria)

Although we breathe in oxygen and breathe out carbon dioxide, many microbes are not quite so restricted, and can breathe anything from sulphur to iron to methane or ammonia. When they do this, they often leave behind solid waste products, such as the above iron oxide filaments, that give away their presence. We can tell these apart from normal minerals in a number of ways, including by the relative proportions of different isotopes in them.

(Image: Schematic digram showing how molecular fossils form and are studied)

However, some of the most important fossils are molecular fossils. Living organisms produce a variety of different organic molecules; even long after the bodies of these organisms decay, those molecules can stay behind in an altered form for millions or even billions of years. If we’re looking for evidence of life on Mars, this might be our best bet.

Enter Perseverance

(Image: Diagram of Perseverance rover showing different instruments)

The Perseverance rover is overall similar in design to the Curiosity rover that landed in 2012, but there are some key differences—and most relevant here is that it’s a geological powerhouse. It’s got a number of instruments designed to carry out detailed geologic investigations:

RIMFAX is a ground-penetrating Radar unit. Like normal Radar, it works by sending radio waves into the ground; different materials affect the radio waves differently, as do transitions between different materials. This will allow us to, for the first time, study the geology of Mars below the surface to get an idea of what has been going on down there.

(Image: This is the kind of result produced by ground-penetrating radar—a rough image of the stratigraphy below the surface.)

PIXL (Planetary Instrument for X-ray Lithochemistry) shoots x-rays at samples and examines how they fluoresce in reaction. This allows for the detection of the elemental composition of a sample—helping us better understand the geology of the area, and potentially detect signatures of life. 

SuperCam is a multi-function laser spectrometer that uses four different spectroscopy methods to examine the composition of samples. They all work in similar ways—essentially, different molecules react to laser stimulation differently, and different amounts of energy are required to make different molecules vibrate. The way that these molecules react can help us identify their composition, and the hope is that this may allow us to detect molecular fossils (these methods allow us to detect molecular fossils on Earth!)

SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) is another spectroscopic instrument—this one, however, is more precise, and optimised for detecting trace biosignatures in samples. It works similar to the above, using an ultraviolet laser to scan a 7 × 7 mm zone for evidence of organic compounds. 

In addition to studying samples in situ, Perseverance will package small samples and leave them behind on Mars. A planned future mission will collect these packaged samples and launch them into space, where an orbiter will collect them and—hopefully—return them to Earth. This would be the first time that samples have ever been recovered from Mars, and would go a long way in increasing our understanding of the Martian environment and geology.

There’s no way of knowing yet what Perseverance will find—but even the fact that a robot palaeontologist is on Mars is incredibly exciting. Here’s to many years of discovery!

I’d love to hear any thoughts on the geology of Hithlum!

-@outofangband

hi hello!

Ok so, prefacing this by saying that I'm far from a geologist and have the absolute basest level of understanding when it comes to tectonic plate formation. That being said, Hithlum on the map gives me Weird Vibes, mainly because of how geometric it looks.

Like look at these maps (first from tolkiengateway second from encyclopedia of arda)

Hithlum looks like... a parallelogram almost. How are we supposed to put plates here to make a parallelogram?

I have seen Hithlum mentioned as a plateau in this thread which... actually checks out pretty well and is one of my favorite theories to date. Some plates push together and force the landscape up, and we can attribute the flatness to shenanigans that happened because of... *spins a wheel, throws spaghetti at the wall* ...the war for the sake of the elves and the chaining of Melkor or something idk. However, the reason I have issues with seeing it as a plateau is the presence of Lake Mithram. Lakes on plateaus do exist (i.e. Ngoring Lake) but - and here's where my lack of geology knowledge really shows - I have absolutely no idea how common they are or how how they interact with the water flow in/out of the plateau. Based off pure unsubstantiated vibes, the map seems to insinuate that tributaries flow from the mountains (Mithram, Ered Wethrin, etc.) down into the main section of Hithlum which would require the main portion of Hithlum to be at a lower elevation than the surrounding area. But if we go back to the plate theory, Hithlum being at a lower elevation doesn't exactly check out.

Unless it's a crater.

(Here's where I put my aerospace hat back on and find a way to come with an absolutely unhinged take for no reason - I may be bad a planetary formation but I feel more confident talking about that than I do geology so bear with me, there's a reason for this madness)

Quick 101: craters are formed when something large slams into a planetary surface incredibly fast, displacing the surrounding material via a sort of explosive process, and leaving a circular-type dent in the landscape. Think moon craters, such as this one bizarrely named Moltke that was spotted and photographed in the Apollo 10 mission.

But moon craters, as with most planetary craters, exist in the vacuum of space where they are largely untouched by the vestiges of time, and therefore may not be particularly accurate when it comes to Beleriand, a place with weather and an atmosphere. Thankfully, we've got a plethora of craters scattered around the corners of Earth, ones that have been worn at by the elements and are less perfectly bowl-like.

One of the most tourist friendly Earth craters. and the one I heard about first, is the unimaginatively named Meteor Crater in the US, as pictured below:

And then it clicked. Because if we do a quick and dirty overlay of Hithlum with Meteor Crater...

What if Hithlum was a crater.

The map cuts off the top section so we cannot tell for certain, but the Hithlum Crater Theory would explain the flow of tributaries from Ered Wethrin down into the crater basin, forming Lake Mithram. There is a bit of an issue in that craters typically do not form mountains surrounding them, but I'm letting it slide a bit because we don't exactly know what things were like pre-crater. Could it have been a jagged landscape or mountainous area? Who knows, not me.

But what of the Mithram Spur? And yes, the existence of the Mithram Spur/Mountains of Mithram does throw the Hithlum Crater Theory off a bit more unless you think of it as a complex crater.

In simple crater formation, such as Meteor Crater here on Earth, you're left with a nice smooth basin. But when complex impact craters are formed, they often leave deposits near the center (thank you PSI for the below graphic) so I'm tenuously chalking up the Mithram Spur up to being some kind of abnormal formation of these deposits, a vestige of the former pre-crater landscape, or some similar unknown combination of factors.

Of course, Valar intervention during the war for the sake of the elves may also be possible - when in doubt just call it some unknown work of the Valar and move on right? But regardless, I find the Hithlum Crater Theory incredible fun because to have a crater, you have to have an impact. What the impact could have been is entirely unknown and opens up a whole new can of worms to sort through.

Hopefully this made sense - I've tried to include links to the resources I pulled from. Hithlum Crater Theory is mostly a theoretical exercise, but if I come up with any further developments on the idea I'll be sure to update!

I don’t know how I missed this before, but in one of her early conversations in the first game Ashley mentions that her mother has a degree in planetary geology. She mentions that her mom decided to settle down to raise her and her sisters rather than go exploring the galaxy.

I like to think that her mom taught her a little bit about rock and landform identification. I like to think that she collects the odd sample here and there when she’s on missions with Shepard and snaps pictures of the landscapes to send back to her mom. 

Her mom writes her back essays about whatever Ashley sent her. Ashley understands some of it, but she just kinda glosses over most of it. But she keeps on feeding her mom’s curiosity about exoplanet geology because it makes her mom happy, and seeing her mom’s enthusiasm makes Ashley happy.

How We Decided

The day after tomorrow- that is, February 18, 2021- the Perseverance rover will attempt to land on the surface of Mars.  It will enter the planetary atmosphere at an acute angle, giving it as much time as possible to experience drag and slow down from orbital velocities.  Because Mars’ air is so thin, and the rover is so heavy, this will fail- in the best case, Perseverance would still be going almost a thousand miles an hour when it impacts the surface.  To help save itself, the craft will deploy a parachute of advanced design, seventy feet across and able to withstand supersonic velocities.  This, too, will fail.  Even with a parachute, there is simply not enough air between Perseverance and the Martian surface to slow it down all the way.  So this is where the rockets kick in.  Once air resistance slows the rover to a bit less than two hundred miles per hour, the heavy heat shield will be jettisoned, and a system of secondary rockets will fire against the direction of motion until it slows to near-hovering.  In a final flourish, the rover will descend from the rocket-boosted frame on coiled springs, until it touches down in the western part of Jezero crater in the northern hemisphere of Mars.

As it happens, Perseverance’s destination was one of the very last things we decided about it- not until the craft itself was fairly thoroughly engineered and designed.  Formally, the decision was made by the mission directorate.  In practice, they follow the consensus of the scientific community, which in turn hashes things out at a series of open-invitation workshops.  Things began with a call for white papers- an open suggestion box, basically.  In 2015, the first workshop narrowed things down from thirty serious proposals to eight candidates.  In 2017, the second workshop further winnowed the list down to three.  And in October of 2018, after three days of presentation, debate, and discussion, the final workshop selected Jezero Crater from these final three candidates using a simple vote of all attendees, and passed on the recommendation to the mission leads.

I haven’t been in the business for very long, so the final workshop was the only one of these where I actually participated.  It wasn’t a close vote as such, and I didn’t break any ties, and technically we were just making a strongly worded suggestion.  Nonetheless, my vote is one of the reasons why the Rover will be going to Jezero Crater instead of Syrtis Major or Gusev, and I think I’m entitled to feel ownership of this mission choice, just a little bit.

(This is, of course, terrifying.)

Having gone through the experience, there were a few surprises worth noting.  The first was how small some of the numbers are here.  The conference was not very large: only thirty proposals, debated by just a few hundred attendees.  I’ve seen book review contests with more entries, and that are read by a wider audience.  Which is to say, this is a situation that was, and is, extremely responsive to individual effort.  In that small a room, populated by people that are philosophically committed to changing their minds when they see good evidence or a good argument, one person can stand up and change the future in a very real way.

The second surprise was the attendance requirements.  Or rather, the lack thereof.  The project is public, paid for by American taxpayers, to whom I am profoundly grateful.  And one way the process reflected that public-spiritedness is that this is not a walled garden.  A small attendance fee (iirc, $40?), and you’re in.  You get a vote, if you want to use it.  A few non-scientists even took us up on this; there’s one retiree (a former schoolteacher, I think) that’s attended every major conference I’ve been to in the last few years, and sets up a small table in the back with his home mineral collection just for fun.  In practice this open-door policy is limited by the obscurity of the event itself; if you don’t move in research circles, you have to be something of a space exploration superfan to hear about it.  Still, as symbols go, you could do worse.

And now that we’re coming up on the day itself, the same kind of public-facing mindset is making me think about why I was persuaded to vote for Jezero Crater, what it means to explore there, and how I’d justify that choice to those of you that made the ongoing discovery of Mars possible in the first place.

If you want to know what Perseverance is like, and what you can reasonably do with it, start with Curiosity- the two are built, more or less, on the same chassis.  That means you have a mobile science lab about the size of a Volkswagon Beetle.  Add some mechanical improvements (no more wheel punctures!) and a few bells and whistles (microphone!  helicopter for some reason!).  Trade out some of the scientific instruments- raman spectroscopy instead of a mass spectrometer, for example.  And it’s got these:

That, dear reader, is a sample return canister.  Not to be returned immediately, alas, but to be returned nonetheless.  One of Persevereance’s primary directives is to find interesting rocks, collect them, and leave them in place for a sample return mission in the early 30s.  There’s a ton of work we can do in situ, but there’s even more we can do in a clean lab back home; things like isotopic analysis really need a much more controlled environment than you’ll get in the field.  And so a major, major consideration is to optimize Perseverance’s landing site for cool rocks that we’d like to take back home.

The other thing that Perseverance is really good at is astrobiology.  There’s no such thing as a life sign detector as such, but this rover represents an attempt to approach that ideal: instruments like SHERLOC and SuperCam are adept at finding organic compounds and fine-scale mineralogy and chemistry that might be influenced by microbial metabolism.  This is a natural extension of what we’ve been learning so far: Spirit and Opportunity showed us that Mars formed under the influence of liquid water.  Curiosity showed us that this was not just wet, but actively habitable: lakes and rivers at a neutral pH under a rich and temperate atmosphere.  The next question along this line is the hardest, and the scariest: we know it was habitable, but was it inhabited?

If you’re like me, that question makes you feel weird.  Collecting rocks is one thing, but a fossil?  The mind rebels.  We’ve spent the last two generations of space exploration tempering our expectations, reminding ourselves that the other worlds in our solar system are largely barren and dead, learning again and again how precious life is in the cosmos.  It’s hard to get in the mindset of people back in the 40s and 50s who could, somewhat reasonably, imagine that Mars might not just host life but multicellular life, vegetation and robust macroscopic ecosystems.  We look back at the science fiction of the era, swarthy soldiers hopping from planet to planet in silver rockets, and laugh at the naivete.  A smile at the exuberance of youth, if we’re feeling generous.  When we were first beginning, we may have imagined ancient canals on Mars and crystal cities on Venus, but that was when space was a blank canvas for us to paint our fantasies.  We’ve learned so much since then, and if it was less fun, at least it was true.  We did the hard thing and accepted reality over fantasy.  We accept that extraterrestrial environments are hostile to life- cratered, silent, and still.  We’re grownups now.

Unless…

Unless.

Imagine that we were born just a bit earlier.  Say, three and a half billion years or so.  We raise our telescopes to the sky, and we see a sister-planet.  Not red, but white and blue, with an atmosphere full of clouds and multiple large bodies of water scattered across its surface, prominent ice caps and snow-capped highlands, rivers tracing their way down to the lowlands in the north.  (Maybe the water is all under the ice, not open to the air at the surface; maybe the liquid pools are small and limited to craters, not feeding a large ocean.)  Sober scientists might have suggested we shouldn’t get our hopes up too much- after all, the gravity is much lower, there’s no tectonic recycling, and there’s no protective magnetosphere.  But is sterility really the default assumption we should be making here?  Is ‘we are alone in the cosmos’ really the most sane conclusion to draw from this situation?  Is it not worth, perhaps, sending a rover to go see?

We’ve adapted our sensibilities to a dead solar system because in the moment we’re looking, it kind of is.  We’re hopeful for the icy moons- and the evidence keeps mounting there as well- but the terrestrial planets are a grim reminder of the fragility and contingency of our own world.  The thing is, the more we learn, the more we discover that we’re a bit late to a very, very interesting party.  Venus is a hellscape, but it probably didn’t start that way.  Mars is a desert, but once it was an oasis.  What makes Earth special among the terrestrial worlds isn’t that it developed a temperate climate, but that it kept a temperate climate for more than four billion years.  Stability, not habitability, is the party trick that makes us unique in the solar system.  And if we’re really committed to being grownups, to accepting what’s real instead of what’s easy, we have to learn that lesson too.

And life does not need four billion years to begin.  Not even close.

That brings us to Jezero Crater.  The most interesting feature here is a large river delta- based on some clever geology, we’re pretty sure that a large river emptied into the crater during Mars’ wet period.  When the rapidly-flowing water hit the still water of Lake Jezero, the loose sediments being carried along the current all fell out of suspension at this place, forming a large pile of detritus at the mouth of the river that accumulated over the lifetime of the system.  Even more interesting, check out this geologic map:

See those tiny teal deposits to the right side of the image?  Those are also river delta deposits.  Which means the thing labeled ‘delta’ on this map isn’t the original extent- it used to be much, much larger, at least twice as wide.  Which also means that the outer edge of the ‘delta’ that we see here in this image is actually an erosional surface, and we get a natural cross-section of the thing with the oldest deposits at the bottom and the youngest at the top, just before Mars lost its hydrosphere.  By climbing the outer edge, we can move through time across a large fraction of the habitable period.

Here’s another image I’d like you to see:

The crater I’ve been showing you is the small circle in the lower right- color is elevation, covering a span of about 5 km.  The black line is the watershed of that river, the region of Mars that channeled water to the delta.  In other words, the river delta collects sediments- and potentially, biosignatures- from a region hundreds of kilometers in diameter, and gathers them all in one place, neatly sorted by time.

For this reason, ancient deltas on Earth are a favorite of paleontologists.  In addition to being comfortably wet and active itself- plenty of access to biologically important nutrients, fresh supplies of liquid water, and a nice dynamic environment- deltas do the legwork for us.  Rather than exploring a huge fraction of the planet with a tiny rover, hoping that we stumble upon an ancient life sign, we can position ourselves at the mouth of the proverbial fire hose and let life come to us.

This does come with some tradeoffs.  Most importantly, whatever we find, we won’t know the original geologic setting.  If we find an unambiguous fossil of some kind- a microbial mat, perhaps- then we’ll know less than if we’d found it in its original home.  And if we don’t find life, then the samples we take will be similarly uncertain.  They’ll be defined in time, at least relative to one another, but not in space.  In the case of life signs, this is an important caveat, but the bare fact of proving that extraterrestrial life exists is sufficiently monumental that it’s still a secondary concern.  But if we’re just talking about geology, that’s a hard thing to lose; that terrifying multi-stage descent isn’t the only risk we’re taking.  We’re leaning into the astrobiology mission hard with this one.

And the search for life is, in itself, fraught.  That’s putting it mildly.  There’s every chance that any evidence that’s even slightly marginal is going to touch off decades of debate, rather than being some kind of slam-dunk.  As it should!  Life is such a fuzzy concept, and such an important concept, that it should absolutely be held to the highest degree of scrutiny we can muster.  This is why it matters that Perseverance includes sample return- in the highly likely case that the findings are disputed, we’ll hopefully have the chance to subject those samples to the highest degrees of scrutiny.  So it feels like the right time to go hunting.

On top of that, there’s the ‘evidence of absence’ problem.  Strong biosignatures update our priors very hard in the direction of life on Mars.  But what is the correct amount of evidence necessary to convince us that Mars never was alive?  I’m not sure, but failure to find microbial mats in Jezero probably isn’t enough.  So the search for life can succeed, but if it ‘fails’ that doesn’t necessarily teach us much; the best experiments teach you something no matter what, and ideally a commitment this large would meet that standard.  This is, more or less, baked into the search for extraterrestrial life, and there aren’t too many ways out from under that problem.

That said, Jezero in particular has some compensation.  As I mentioned, we’re collecting a lot of good data regardless; and even without the gologic context, there’s a ton of opportunity to sample different minerals and how they formed, and get a nice broad sample of the Martian surface over time.  And, even better, here’s the location of another interesting potential field site, in northeast Syrtis:

Note the proximity to Jezero crater!  And Syrtis is also a fantastic candidate for a sample return mission.  It has exposed mesas with layered outcrops going all the way back to the earliest days of Mars, and extending (potentially) through many of the most interesting periods.  Now, these are not ideal for the search for life, although they’d give us a ton of technical data about surface chemistry and the behavior of the atmosphere during the early, wet periods; it would go a long way towards resolving arguments about the temperature of the early Martian climate, for example, or tracing the early destabilization and loss of the magnetosphere while teaching us loads about the planet’s core.

Those mesas are still pretty far away.  Too far, probably, for a sensible rover lifespan to make it all the way there.  But there’s a plan- called the ‘Midway’ route, as a nod to the compromise nature of it.  See, halfway between Jezero and these mesas, there are a lot of banded rocks that look suspiciously like they’re sourced from the table mesas in Syrtis.  And those, we can get to, maybe.  If we call a specific deadline on looking for life in Jezero, then we can pivot to Midway and hopefully take a really deep look.  So, in the end, we’re going hard for astrobiology research, but we’re not going all-in.

The importance of the search for life is… well, there are a lot of people out there, and we enter the world in a lot of different ways.  Most of us agree that the existence of extraterrestrial life would be a Big Deal, and we tend to have a lot of different reasons for that.  It’s not a bad subject for a future post or three, in fact.  But there’s one thing lurking in the back of my head that’s a non-obvious reason to go looking.  This wasn’t discussed at the workshop particularly, but it fed into my vote somewhat.  Check the logic of this for me, see if it makes sense:

Worrying about existential risks, we sometimes talk about the ‘great filter’.  That is, the mysterious phenomenon which explains the lack of extraterrestrial civilizations reaching out to us.  Now, maybe we’re in a zoo or a preserve or something, and intelligences are out there watching after all; maybe the Earth really is the center of the cosmos, because of the simulation hypothesis or the various religious explanations.  There’s no real way to know for sure at this point.  But consider the space of very real possibilities where the universe actually is material, and actually is mostly barren.  Why?

Stepping through the sequence, it might be that abiogenesis is really hard- going from a temperate world to a living one is almost (but not quite) impossible.  Maybe there’s some hurdle to clear between genesis and encephalization.  Maybe, given encephalization, civilization and tool-use are almost impossible.  Or maybe there are many civilizations like ours, and the great filter is ahead of us- it is almost impossible for technological civilizations not to self-destruct or turn in to lotus-eaters before they reach interstellar civilization.  There are a lot of possibilities for the filter, and for present purposes we’ll divide them into two categories: those which we would have already passed, and those which are in our future.

And here’s the thing: for each possibility we can exclude from the great filter, all the other possibilities increase commensurately, becoming more likely in our estimation.  (Assuming the exclusion is ‘clean’ and doesn’t favor some other possibility, that is.)  Given that the silence continues, if we could somehow prove that technological self-destruction isn’t a big risk, that would commensurately increase our guesses about how hard abiogenesis is.

Life on Mars, especially if we could be very sure that it evolved independently of Earth life, would be a strong argument against the difficulty of abiogenesis.  One biosphere in the solar system, and nowhere else, might be down to luck.  The one biosphere has to be somewhere, right?  Two in the solar system, and nowhere else, is a good bit less reasonable.  If we find a second genesis on Mars, then we’ve learned that life is not rare.  That the hundreds of billions of stars in the Milky Way are likely host to many billions of different living (or at least once-living) worlds.

And as wonderful as that news is, as much as it makes me so happy that I literally had to take a second to cry on my bed for a bit, it also makes the great silence much, much scarier.  Today, we can reassure ourselves by saying that life may be rare in the universe.  But what if it isn’t?  If the cosmos is full of life, but not full of thought, then…

If this is the case, we need to know.  We need to know as soon as possible, and we need to know it while we’re engaged in the great project of technological development and moral progress.  It’s easy to imagine that this particular mission is one that can be framed in purely positive terms- the joy of discovery, the vastness of truth, the love of how things might be.  But I do also have this sense of civilizational fragility, you know?  And understanding the risks that we face and the chances we’re taking- that’s not idle curiosity.  That’s genuinely urgent.

i’ve been trying to figure out what cybertronian geology is like for years and so far i don’t have many conclusions, but i fuckin love the ones i do have lol. Here’s my ramble, part New Shit and part stuff i posted on a different site a couple years back:

Primus (Cybertron) and Unicron (Earth) are entities that are kind of like interstellar whales, or alternatively, vacuum cleaners. They float around the cosmos in search of Space Dust that contains interesting and useful elements, which is gobbled up, mined for tasty bits, and stored in a planetoid body around their cores. Under normal circumstances, the core entity is continually and actively moving stuff around inside the planet, meaning that these planets tend to be extremely tectonically active and thin of crust. 

Beneath the stored Space Dust, there's a 'skeleton body' that can be built upon, and if necessary the planetary body (which is mostly storage) can be shed/recycled to allow Primus to fuck off and do whatever without carrying a whole planet around. However, shedding this extra mass results in the destruction of the planet - so it's kind of a last resort, as long as you give a fuck about what's crawling around on your surface. 

Primus' 'skeleton body' folds down into an 'alt-mode' that's more or less an enclosure for a primordial spark. Primus, recovering from the battle against Unicron, went dormant for a long time, entering this alt-mode form and drifting through the young universe, collecting Space Dust along the way. Primus used these collected minerals to recuperate, and then had the great idea of creating the Thirteen - which were also formed out of that space dust, purified and alloyed together by Primus and given life with a spark split from Primus' own. And then the Thirteen got together and had their own kids, and Primus was like "Ah. I have grandchildren."

Primus has therefore spent the last 4.5 billion years more or less napping, meaning that Cybertron is much more stable than it ought to be. It still has some pseudotectonics, but the result of this activity is more like when you have a restless night’s sleep and you wake up and all the blankets have fallen off to one side lol. There is not as much internal heat inside Cybertron as there is on Earth; the role of convection is mainly filled by various Primus Bullshit processes, like the giant fuckin arms that rove (extremely slowly) through the mantle, looking for the snacks Primus hid at the back of the metaphorical fridge eons ago and forgot about. These arms also channel the byproducts of Primus’ consumption back up to the surface, where these byproducts occasionally become useful to Cybertronians.

This happens mainly in rift zones, alongside volcanic and pseudovolcanic features which are essentially god farting. Volcanism is rare and tends to be of the gaseous, explosive variety because of cooler internal temperatures and the way everything comes to the surface all jumbled together.  

There are... three? layers to Cybertron:

the central core, which is relatively small and all Primus. The core is immobile, most of the time (pls insert the free real estate meme here, only with Megatron holding some dark energon) because if the core moves, Shit Is Going Down.

an intermediate layer, which is made up primarily of sensibly-arranged Space Dust. Like Earth’s mantle, it is a solid which acts like a liquid over sufficiently large timescales, meaning , There’s also some of Primus' skeleton arms and a few extra structures left over from when the Thirteen were being built and trained, such as the Well of All Sparks. Primus maintains these bc it’s nice to be able to talk to the grandkids once in a while.

and then a surface layer which is more or less analogous to the Earth's lithosphere, formed of the most recent Space Stuff acquired by Primus (during the Dynasty of Primes and especially the Cataclysm). This forms a single but not 100% whole tectonic plate which gets stretched and thinned and crumpled up in places due to Primus’ pseudotectonic activity.  There are crumple zones, such as the Main Divide and the Manganese Mountains, where two regions of the surface are being pushed together and thickening, folding, fracturing and welding back together under the pressure. There are fracture zones, where the surface is being pulled apart in all sorts of directions and so the crust thins and a complex system of rift valleys and depressions opens up - one of these runs from the northeastern Sea of Rust up into the Mitteous Plateau, a former crumple zone now being worn down by erosion.

Unicron on the other hand got well and truly knocked tf out by the Thirteen, allowing the planetary mantle of the Earth to develop more or less like a normal rocky planet. This meant that a lot of the best elements sank down to Unicron’s core on their own and Unicron is now both fast asleep and absolutely lost in the nickel/iron sauce. 

water.

this story takes us somewhere quiiite else today! oof, for me it was the hardest one so far in the july writing challenge!~

__________

"Space Station Ceasar, log number 303, Commander Yang recording. Earth time 24th April, 2281. Day 79 of the 37th mission to Venus, conducted by the employees of and sponsored by the Self-Governing Institute of Cosmology, Astronomy and Explorational Physics."

"Come on, Commander, get to the exciting bit!" impatiently interrupted Martinez. They had picked up a stack of printed reports to make a megaphone and were now speaking through it. Them being on a far off cushioned seating was still too close to Yang's ear. She gave them a harsh look to pipe down.

“The planet’s weather is reportedly within parameters, the crew of three remain in an optimal health condition."

"Except for Tiwari's endless migraine", Martinez was more energetic than ever, but with the usual side of snark. Commander Yang showed Martinez to the tightly sealed exit, but they did not even move, instead adding, "a bit ironic for a Medical Officer, if you ask me."

After a sigh, she continued.

"The scouting mission was conducted in accordance with the protocol; the cooling system of the exploration shuttle is fully operational. The cabin’s pressure was stable, and the investigation was predominantly conducted by bots, that is, two units of HHR-34 model. And there were... some rather exhilarating findings. I personally made the decision to step outside the craft, in the descent pod, of course. It is too soon to tell whether…”

"We found water, guys!" shouted Martinez, finally letting the excitement come gushing rather than bubbling on the surface. 

"Yes," Commander Yang had no doubt this last outburst made it into the log."We have found a source of what seems to be water. We are slow to rule out other options, but so far it matches with our on-board samples."

She looked back at Martinez, all starry-eyed, like a teenager. To this day it remains a mystery to her what made them join such a monotonous mission, and more bewilderingly, planetary geology altogether. Not that it was not a good field to be in right now, there was much use for it ever since humanity started to run low on certain elements, but you would never take Martinez for a person who could study soil for hours. They could, obviously, and they did, regularly. But they had never been as excited about rocks as to be grinning from ear to ear until dinner and then some.

"This is nothing short of a miracle," they exhaled, kicking back on the sleeping pod. They picked up a paperback from underneath it and held it against their chest.

"Miracle is a bit much," Tiwari scraped the spoon against his bowl. "It's a tiny vein of a river in the closest thing to hell in our solar system."

"Which is precisely what makes it a miracle!"

"Water finding was not in our mission's objective, and for a good reason," offered Commander Yang after a moment. This thought had been persisting ever since she scooped up a sample from the river, and now she gave herself room for contemplation. "VALHALLA clearly established that it is not possible in the conditions of Venus. There is simply no way for water to be held together. It is, for the lack of a better word, unnatural."

The worry in Commander's face made Martinez put their thinking cap on for the first time this whole evening.

''There is temperature and pressure variance everywhere, even back on Earth. Is it odd? It is! Is it entirely outside of the realm of possibility? No! It cannot be unnatural if we did, in fact, find it,” they felt Tiwari wanting to get a word in, and likely more than one, so they brazenly carried on and at a higher volume. “Just because Mars has been successfully colonised does not mean we are now experts! There is nuance, character. I can't believe I even have to explain it to you, guys, we work IN the department of planet exploration. Scientists are always learning. And science is where errors happen all the time."

"Not the kind that contradict everthing we already know," said Tiwari. It did not seem like he was up for taking this discussion further after being cut off earlier. Instead, he was headed for the button to leave the quarters.

"Ah, ah, ah! You are off the clock, Officer." Commander Yang called out to him, in a reprimanding tone. "No more lab time for you”.

This incited what has by now become a solid routine, where Tiwari insists that he cannot sleep with a headache, and Commander retorts that he cannot properly work with one either. It ends usually like this: Tiwari promising to stay in the quarters, listening to music until the others fall asleep and sneaking out later anyway. Martinez never has any lines in this, though, save for the comment when Tiwari puts the earphones in.

"Reasoning with a health practitioner about health has never been so easy!”

"I can still hear you," he groaned.

"Good! I honestly hoped so!" loudly proclaimed Martinez and picked up the paperback on their chest. They cracked the spine for easy reading. It reminded Yang to fish out a book of her own from the space below. She and Martinez had few things in common, but sentimental attachment to printed literature instead of hand-held devices was one of them.

''Another serial killer?'' she asked.

“Indeed! It better be juicy. Last one was kinda meh, the killer's smarts barely held that mystery with glue and tape. It was obvious who did it after the first couple of corpses.”

"Jeez, I could never... Thinking how far from civilisation we are gives me the heebie jeebies enough. I'll stick with my cheesy happy endings, thank you very much!'' she flashed the cover of something where a couple was clearly ready for smooching.

“Oh no, but that's just it, though. We are far from civilisation, and people are the scariest thing on planet Mars, or Earth, for that matter! Sure, Venus has its moments, but you can definitely rest easy knowing no murderer will come knocking at the station's gate in the middle of the night. They wouldn't even know when night ends and begins, for starters!'

But sooner or later, an arbitrary night arrived at the station. Reading lulled them both to sleep, and the light stayed on, as ever present radiance of the moon. 

It was all silent until it wasn't.

“Science officer Ma-a-a-rtinez,” sang a familiar voice. “Wakey-wakey."

It was Commander Yang, but it sounded nothing like her. No false, nauseating sweetness had made them this alarmed before. Martinez opened their eyes. Not to stranger’s knocking, or tapping on the black out windows. There was, however, a strange scraping sound close to their ear. They took a minute to find their bearings and still were left helplessly confused.

“Commander,” they had to swallow despite their mouth feeling dry. “What's that in your hand?”

“A knife, Science Officer Martinez."

"Why do you have a knife, Commander?''

"We are astronauts, Martinez," she said as if a tad confused. "Of course we have knives."

It did not clarify why she had one in the quarters. Or why she had it so close to their face. They quickly glanced around the room, just to see that Tiwari was gone. The panic started to increase, ringing in their ears, as they knew it was not some sick joke. Yang played no such tricks. She was the straightest arrow, and having something pointing at Martinez now was serious business.

The book they fell asleep with was still tucked under their chin, and one lucky motion helped knock the knife away from the left side of their face and onto the floor. Without looking back, they made a dash to the end of the room and pressed the button to open the vent to the main hall.

It was decidedly not Commander Yang.

NASA mission aims to study ice and water on the moon's surface In the fall of 2023, a U.S. rover will land at the south pole of the moon. Its mission: to explore the water ice that scientists know lurks within the lunar shadows, and which they believe could help sustain humans who may one day explore the moon or use it as a launching pad for more distant space exploration. NASA recently selected Kevin Lewis, an associate professor in the Krieger School's Department of Earth and Planetary Sciences who has also worked on missions on Mars, as a co-investigator of the mission. Using part of the rover's navigational system, he plans to explore the moon's subsurface geology from his office in Olin Hall. "I have been on other rover missions, but on Mars, so I'm a little bit new to the moon," Lewis said. "We're going to see into shadows that have never seen the sun, let alone been seen by humans. So it could be a very different type of surface than we've seen in other photos of the surface of the moon." Drier than a desert Most of the moon is completely without water. That's because of the way the satellite was formed, in a giant impact between the proto-Earth and a Mars-size object. Temperatures were high enough not only to melt rock, but to vaporize it, causing a cloud of rock vapor to orbit Earth. The vapor eventually coalesced to form the moon. Those temperatures were also high enough to drive off any water, not even leaving appreciable traces trapped within rocks the way it is on Earth. But over time, meteors and comets containing water ice bombarded the moon, sending ice molecules hopping around the lunar surface. The sun's angle at the moon's poles is steep, creating long shadows. This means that some of the polar craters receive no sunlight at all. When the water molecules happen to hop into one of those unlit areas, whose temperatures are among the coldest in the solar system at just tens of degrees above absolute zero, it drains their thermal energy and they remain stuck to the surface. "So, over time, you could build up ice deposits in these permanently shadowed regions, which might be basically the only source of water on the entire moon in useful quantities," Lewis said. Roving the moon The Volatiles Investigating Polar Exploration Rover, or VIPER, is a golf cart-sized robot designed for the extremes and unknowns of the moon's south pole. The rover, which will travel several kilometers over several lunar days—or about 100 Earth days—will assess things like what form the water is in, how much of it is there, whether it's more like frost on the surface or ice at depth, and whether there's more of it in some areas than others. Currently being assembled at NASA's Johnson Space Center in Houston, VIPER has to be customized for the specific conditions it will encounter at the moon's south pole. There's the cratered soil with various levels of compaction, requiring four independently controlled wheels that can handle slopes of 25 to 30 degrees. There are the moon's drastic temperature swings, ranging from 225 degrees Fahrenheit in the sun during the day to -400 degrees in those permanent shadows; VIPER's boxy shape protects the instruments, and calibrations of the high-precision technology are currently underway to guard against those swings. There's the darkness itself, necessitating the first headlights ever used on a rover, to illuminate places on the moon that have never seen sunlight. And there are the conflicting needs of science and logistics—the science calls for VIPER to spend its time in the shadows, but the rover will also need to periodically climb out of the craters to recharge its batteries in the sunlight. Most rovers' solar arrays are located on their roofs, but the angle of the polar sunlight requires VIPER's arrays to be mounted on its sides instead. The quest NASA selected eight new VIPER co-investigators, in part to bring new ideas and expertise to the team. Lewis' investigation effectively gives the rover a whole new science instrument for probing the moon. To track its position and orientation, VIPER is outfitted with accelerometers—devices that are typically used to determine changes in position and rover tilt. These are the instruments that Lewis plans to repurpose for his research. The accelerometers are extremely sensitive; they can detect the minuscule change in gravity you would experience if there was an ore deposit beneath the ground you are standing on. "Gravimetry has been utilized for prospecting on the Earth; you can look at gravity anomalies, and they will tell you something about the subsurface geology," Lewis said. "We've been able to do that on Mars and figure out the density of the subsurface rocks we're driving over. We're going to do that on the moon as well, and try to figure out the vertical density of the regolith and look for any geological anomalies." VIPER is part of NASA's Artemis program, a multi-phase process to return humans to the moon. Artemis I will be the first test of the rocket that will eventually carry humans, and is scheduled for launch this year. Artemis II, scheduled for 2023, will orbit the moon with humans aboard. Artemis III is planned to land humans on the surface of the moon in 2024. "It's pretty wild to be working on the VIPER mission in parallel with the human exploration side with the Artemis program," Lewis said. "Even though those astronauts would not directly be drinking this water, it's very cool to be doing this against the backdrop of actually returning to the moon." As a member of the science team, Lewis isn't involved in constructing VIPER, and he won't be directly handling any of the controls during the mission. But since joining the team, he's been involved in simulated operations, where the team practices using the rover's technology and making the kind of decisions that will need to be made on the spot. The mission is beginning to seem real. "It's just really exciting to be prospecting for water that could potentially be used by human explorers someday," Lewis said. "Finding water that they could drink a bottle of someday—that kind of blows your mind. And of course the geology side of it: The history of the moon and the geologic and thermal evolution of its crust are also very interesting questions."

Earth’s atmosphere 2.7 billion years ago may have been more than two-thirds carbon dioxide. That finding comes from a new study that simulates how the ancient atmosphere may have interacted with bits of cosmic dust falling through the sky.

Such a carbon dioxide–rich atmosphere may also have created a powerful greenhouse gas effect, researchers suggest January 22 in Science Advances. That, in turn, could help answer a decades-old conundrum known as the “faint young sun paradox:” how liquid oceans could have existed on Earth when the sun was about 30 percent dimmer than it is now (SN: 4/18/13)

Estimates for atmospheric carbon dioxide during the Archean Eon, which lasted from 4 billion to 2.5 billion years ago, vary widely. “Current estimates span about three orders of magnitude, from about 10 times more than now to a thousand times more,” says Owen Lehmer, an astrobiologist at the University of Washington in Seattle. So scientists have hunted for data that can shrink that range.

Enter a group of 59 micrometeorites found embedded in 2.7-billion-year-old limestone from the Pilbara region of northwest Australia. These carefully preserved meteorites were first described in a 2016 study in Nature, and are still the oldest fossil meteorites ever found, by about 900,000 years. As such, they offer a rare glimpse into the atmosphere of a lost world.

The tiny bits of rock, no wider than a human hair, zoomed through the atmosphere of ancient Earth. Made of iron and nickel, the micrometeorites heated up as they plummeted, melting and then refreezing before landing in the ocean and sinking to the seafloor. There, they became slowly entombed in limestone.

During their brief, partially molten state, the micrometeorites chemically reacted with Earth’s atmosphere. Some atmospheric gas — whether oxygen or carbon dioxide — oxidized the iron, snagging its electrons and transforming the original minerals into new minerals.

Based on chemical analyses of over a dozen of the micrometeorites, the original 2016 study suggested that the degree of iron oxidation points to a surprisingly oxygen-rich upper atmosphere 2.7 billion years ago, not dissimilar to today’s 20 percent oxygen.  

But that answer was never wholly satisfying, Lehmer says.

Based on data gleaned from Archean outcrops, scientists generally agree that there was very little oxygen in the atmosphere right at Earth’s surface during the Archean. So a lot of oxygen much higher up would mean a layer cake–like stratification, with two very different atmospheric compositions at different altitudes.

“It’s not clear that’s impossible, but it’s difficult to imagine an atmosphere in that state,” Lehmer says. “Every atmosphere that we can see on terrestrial planets is well-mixed,” stirred together by swirls and eddies and chaotic flows of air. “Turbulent mixing prevents that stratification from occurring.”

So Lehmer and his colleagues decided to tackle the elephant in the room. What if carbon dioxide, rather than oxygen, was responsible for oxidizing the iron? Both can be oxidizers, although free oxygen reacts much more quickly than oxygen bound up in CO2. Still, Lehmer says, “if you can’t have a stratified atmosphere, it’s reasonable to think there was little to no oxygen.”

To test how well carbon dioxide could oxidize fast-moving micrometeorites, the team simulated the journeys of about 15,000 bits of cosmic dust, ranging in size from two to about 500 microns, as they entered Earth’s atmosphere and arced groundward. The tiny bits of rock swooped in from various angles and moved at different speeds, altering how much they might melt. And the team also had the rocks pass through atmospheres with a range of carbon dioxide concentrations, from 2 to 85 percent by volume.

The simulations suggest that an atmosphere made up of at least 70 percent carbon dioxide could have oxidized the micrometeorites, rather than a stratified atmosphere with an upper atmospheric layer enriched in oxygen. That’s also consistent with other lines of evidence suggesting a carbon dioxide-dominated atmosphere during the Archean, including analyses of ancient soils weathered from rocks, the team says.

Such a CO2-enriched atmosphere, along with a healthy dose of the even stronger greenhouse gas methane, also could have created a warm, greenhouse world. That could make it the long-sought answer to the faint young sun paradox.

“It perhaps doesn’t solve the whole puzzle. But it puts an important piece in place,” Lehmer says.

“They do have a point,” says planetary scientist Matthew Genge of Imperial College London, a coauthor of the 2016 Nature study. Genge acknowledges that the idea that there might have been a layered atmosphere was surprising even then. But “I think the jury is still out” on whether oxygen or carbon dioxide was responsible for oxidizing the cosmic dust, he says.

Lehmer’s team’s simulations suggest CO2 could have reacted quickly enough with the iron to oxidize outer layers of the rocks, or even fully oxidize them. But such simulations of reaction times “are an ideal case,” Genge says. “Under these conditions, reactions are as fast as possible,” but such speedy reactions may not be realistic. More chemical analyses of actual micrometeorites may help scientists put realistic bounds on the simulations.

The wonder of it is “that there are little rocks that let us do geology on the atmosphere so far above the ground,” Genge says. “It is exciting that these tiny particles, which still fall all around us, allow us to peer so far back in time.”

Its a Ring

@ohmybribri​ requested this a bit ago (sorry for taking so long!!) 76 and 82 with Bri? Pretty please???? 😘

73. I came here to explain what happened and 82. I can't stop thinking about you

You and Brian had been dating for a little over three years. You met through John and your sister Ronnie in one of Freddie’s parties. This one had been Grecian themed to this Ronnie told you straight up to dress up. Not only because it was mandatory by the hosts but because she had been planning on setting you up with a certain guitarist.

John had been kind about it but kept out of his wife’s machinations for the most part. He also wanted his friend to be happy and despite this being a set up, he knew you’d be good for Brian.

The day of the party, Ronnie spent dressing you up as Eos Goddess of the Dawn. You didn’t think you’d fit the part considering that Greek and Roman goddesses alike were known for the beauty and power. You didn't think you were up to par to be such a goddess. You personally would have done well being a nymph or faerie.

“You need to go as the Eos though (Y/N),” Ronnie said with a wide smile.

You rolled your eyes at this but comply and let her help you put the toga dress on.

At the party, you were getting on amazingly with Freddie and Roger who were with their respective partners. Food was being passed around and been informed their fourth member had yet to arrive.

You’d drifted onto the balcony to get away from all the smoke and cool yourself down. Thankfully it had been empty allowing you a moment to yourself. After being out there for a bit you made to go in bump into a tiny body. You look down to see a tiny head.

You alright there dear?” You asked picking up the tiny boy.

He nodded and held on to your neck as you made your way to the balcony.

“What’s your name?” You ask him as you made your way to the balcony.  

“Jimi,” he said through hiccups.

“Good to see you Jimi,” you said gently before introducing yourself and asking, “Where’s mum and dad, hm?” As you sat on the bench you’d just vacated sitting her on your lap.

“Mummy gone,” he said tearfully clearly in distress about it.

“And daddy?” You asked.

Before she could reply you heard someone yelling, “Jimi!”

“Daddy?” Jimi said looking up from where he sat on your lap before crying out, “Daddy!”

You looked up to find an incredibly tall man dressed to the nines as who you believed is Astraeus the god of dusk.

“Oh thank goodness,” he said as he landed on his knees before his son and pulling him from your lap into a strong hug all the while saying, “Don’t you ever run out like that again.”

You made to stand to give the father-son duo a moment alone when he spotted you.

Brian stood up, little Jimi still in his arms, and said, “Thanks for finding him, I’ve been running up a storm looking for him.”

You gave him a kind smile and said, “He bumped into me more like, I was just about to head back in.”

“She finded me daddy,” Jimi said into his father’s neck, “Ms. (Y/N) finded me.”

“(Y/N)?” The man asked curiously, “Ronnie’s sister?”

You nod with a small grin.

“Oh where are my manners,” he said shyly as he extended his free hand saying, “Brian.”

“Nice to meet you Brian,” you say with a small laugh as you shook his hand before giving a little hum and saying, “Or should I call you Astraeus?”

He laughed a delight filled laugh at this and said, “Never thought anyone would recognize that let alone know.”

“I’m an astronomy major,” you say with a grin.

Brian’s eyes brightened at that and asked, “What’s your focus?”

“I’m not too sure where to go yet,” you say honestly, “I love learning about a start’s structure and evolution. But I also love planetary geology.”

This seemed to intrigue him that is when he looked at you and noticed your costume and asked, “Is this why you are the Eos to my Astraeus?”

You blushed bashfully at that and nodded.

He motioned for you to sit on the bench before adjusting his grip on Jimi and also sitting. 

The both of you spent a good amount of time outside alternating between talking about your shared love for space and entertaining Jimi. 

Unbeknownst to you and Brian, Ronnie and the rest of the boys looking in each with smug smiles on their faces at what they were seeing.

----

No less than a week later you got a call from Brian?” You asked a smile appearing on your face as you took a seat on your kitchen table.

“Blame Ronnie,” he said with a laugh.

You laughed along with him at that and said, “How may I help you?”

“Well...I was wondering...” He rambled before clearing his throat. “Yes?” You ask a grin in your voice.

“I can't stop thinking about you,” he said after a moment of silence.

“Oh,” you say softly not having expected him to say that. 

“So I was wondering if you wanted to go to dinner?” He asked with a bit of confidence. 

You’d quickly agreed and here you were three years later. During those three years he explained how he and his first wife divorced which was why Jimi had gone running the night they met. 

Tonight is a special night, it is the anniversary of the day you met. And you have, what you hoped are, good news to tell Brian and Jimi. You were out with Jim and Ronnie when you spotted him at the cafe that was across the street from the bookstore you were going into. You were ready to make your way to him when you saw a woman sit on the empty chair in front of him.

Your heart broke at the sight. Was he not happy with you? That would cause him to stray? Was he even cheating on you? He’s sitting there with a beautiful woman...having lunch...that he’d said he was going to be taking with the boys. He’d lied to you. But why?

Unknown to you, Ronnie knew who Brian was meeting with and why. She did her best to keep you distracted but that only did so much.

When you got home, you promised Ronnie you wouldn’t do anything stupid. Like pack a bag for a night and disappear. NO you waited and left to see what Brian had to say for himself.

You hear the sound of keys as he opened the door.

“(Y/N) I’m home!” He called out as he took of he took off his coat and closed and locked the door.

“You clear your throat and make sure your eyes were dry before going to greet him.

You weren’t hiding it as well as you thought because the large smile on his face fell when he saw you.

“Are you alright?” He asks approaching you.

You shook your head as tears fell and sobs racked your frame.

Brian went to take you into his arms but was shocked when you pulled away.

“I saw you,” you said as you kept taking steps away from him.

“What?” 

“With that woman today...I saw you!” You say through sobs.

His eyes widened at what you’d said.

“I swear it’s not what you think,” he says anxiously as he follows after you when you turn to make your way to your bedroom where you had an over night bag ready.

“Please don’t leave!” He begged, “We can talk about this! I swear it wasn’t what it looked like!”

“You were having lunch with a woman you were familiar with,” you said simply giving him the benefit of the doubt.

“That part is true,” he said after taking a calming breath, “I was having lunch with a woman today.”

You slumped on the bed and sighed trying not to let your imagination and insecurities take over.

“Ronnie gave him a hint that you’d seen me it’s why I came here to explain what happened,” he said as he got down on one knee and taking your hands in one of his as he took a familiar looking box out of his shirt pocket.

“You were...” you said as understanding dawned on you.

He smiled at you as he opened the box to reveal a gorgeous ring.

“(Y/N) Tetzlaff, you are the most amazing woman I’ve had the honor and pleasure of meeting,” he takes the ring out of the box and asks, “Will you do me the honor of being your husband?”

You smile widely and jumped off the bed wrapping your arms around him tight knocking you both down as you did.

“Yes,” you said before kissing him deeply.