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On May 30th, the Mars Curiosity rover was just minding its own business exploring Gediz Vallis when it ran over a rock. Its wheel cracked the rock and voila! Pure elemental sulfur spilled out. The rover took a picture of the broken rock about a week later, marking the first time sulfur has been found in a pure form on Mars.

After Curiosity’s encounter with the broken rock and its pure sulfur innards, the rover trundled over to another rock, called “Mammoth Lakes” for a little drilling session. Before it left to explore other rocks, the rover managed to cut into that rock and take samples for further study to find out its chemical composition.

It’s not that sulfur isn’t prevalent on Mars. It is, but in different forms. The stuff is highly abundant in the Solar System, so this find isn’t as surprising as you’d think. However, Curiosity finding pure sulfur in the middle of broken rocks is a new experience in Mars exploration. So, of course, that’s raising questions about how it got there and its implications for habitable environments in Mars’s long history.

Curiosity’s Peregrinations

At the moment, the Curiosity rover is making its way through the Gediz Vallis. That’s a flow channel winding its way down a section of Mount Sharp (aka Aeolis Mons). That’s the central peak of Gale Crater. The rover has been heading up since 2014, charting different surface layers as it goes. Each layer was put down during a different era of Mars’s history. They could contain clues to the planet’s habitability in the past.

NASA’s Curiosity Mars rover captured this view of Gediz Vallis channel on March 31. Floods of water and debris piled rocks and sand into mounds within the channel. The rock the rover broke lies in a channel in this region.
 Credit: NASA/JPL-Caltech/MSSS 

Fast-moving liquid water raged over the surface and carved Gediz. The floods carried a lot of rocks and sand and deposited them all along the way. Other piles of flood debris lie around the region, bearing witness to other ancient floods and landslides. “This was not a quiet period on Mars,” said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of the Mast Camera, or Mastcam on Curiosity. “There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows.”

Understanding Sulfur’s Presence

The surface materials in Gediz contain high amounts of sulfates. Those are sulfur-bearing salts that appear as water evaporates. They are a chemical clue that water existed in the region. Judging by some parts of the surface, it also appears the water ponded at some times, in addition to the floods that scoured the landscape and then deposited debris.

Now the planetary science team has to explain how a pure form of elemental sulfur got stuck in the middle of rocks, according to project scientist Ashwin Vasavada. “Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” said Vasavada. “It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”

Putting Sulfur in Context

Sulfur, of course, exists on Earth, which helps scientists understand its behavior and the environments where it’s found. The presence of sulfur can be a result of various geological processes. The sulfur “cycle” includes the flow of sulfur from the core to the surface through volcanism. That’s not unusual. Sulfur commonly appears around volcanic vents. Mt Ijen in Indonesia is a good example. It sports extensive elemental sulfur deposits that are mined.

Traditional sulfur mining at Ijen. Candra Firmansyah. CC BU-SA 4.0.

The volcanic moon Io in the Jupiter system features patches of different allotropes of sulfur. They’re also volcanic in origin, spewed out along with widespread lava flows. This moon has more than 400 volcanic features, making it the most volcanically active (and sulfurous) place in the Solar System.

The Jovian moon Io is seen by the New Horizons spacecraft. The mission’s camera caught a view of one of this moon’s volcanos erupting. The region that Curiosity is investigating shows evidence of different kinds of sulfur-bearing minerals. Courtesy: NASA Goddard Space Flight Center Scientific Visualization Studio.

The pure sulfur in the Mars rock most likely came from volcanic processes. They occurred sometime in the past, but that doesn’t answer how the crystals got inside the rock it crushed. Scientists have known for years that Mars was extremely volcanically active in the past. For a long time, they also thought it was dead, or at least dormant. The planet has no plate tectonics like we see on Earth, either. However, the Mars InSight mission found evidence of some seismic activity on the planet in 2021.

In 2023, planetary scientists at the University of Arizona offered up evidence of a giant mantle plume under Elysium Planitia that drove some kinds of activity in the more recent past. Gale Crater lies in this region and could well have experienced related volcanic and seismic activity during the recent geologic past. If so, that could help explain the presence not only of pure sulfur but also the flood-related sulfates deposited on the surface.

For More Information

NASA’s Curiosity Rover Discovers a Surprise in a Martian Rock
Recent Volcanism on Mars Reveals a Planet More Active than Previously Thought
Sulfur on Mars from the Atmosphere to the Core

The post Curiosity Drives Over a Rock, Cracking it Open and Revealing an Amazing Yellow Crystal appeared first on Universe Today.

One of the challenges engineers face when developing technologies for use in space is that of different gravities. Mostly, engineers only have access to test beds that reflect either Earth’s normal gravity or, if they’re fortunate, the microgravity of the ISS. Designing and testing systems for the reduced, but not negligible, gravity on the Moon and Mars is much more difficult. But for some systems, it is essential. One such system is electrolysis, the process by which explorers will make oxygen for astronauts to breathe on a permanent Moon or Mars base, as well as critical ingredients like hydrogen for rocket fuel. To help steer the development of systems that will work in those conditions, a team of researchers led by computational physicist Dr. Paul Burke of the Johns Hopkins University Applied Physics Laboratory decided to turn to a favorite tool of scientists everywhere: models.

Before we explore the model, examining the problem they are trying to solve is helpful. Electrolysis immerses an electrode in a liquid and uses an electrical current and subsequent chemical reaction to split atoms apart. So, for example, if you put an electrode in water, it would separate that water into hydrogen and oxygen.

The problem comes from reduced gravity. As part of electrolysis, bubbles form on the surface of the electrode. On Earth, those bubbles typically detach and float to the surface, as the density difference between them and the remaining liquid forces them to.

Dr. Burke presented alongside other experts at the Space Resources Week Workshop back in March.
Credit – ESRIC YouTube Channel

However, in reduced gravity, the bubbles either take much longer to detach or don’t do so at all. This creates a buffer layer along the electrode’s length that decreases the electrolysis process’s efficiency, sometimes stalling it out entirely. Electrolysis isn’t the only fluidic process that has difficulty operating in reduced gravity environments – many ISS experiments also have trouble. This is partly due to a lack of complete understanding of how liquids operate in these environments – and that in itself is partly driven by a dearth of experimental data. 

Which is where the modeling comes in. Dr. Burke and his colleagues use a technique known as Computational Fluid Dynamics to attempt to mimic the forces the fluids will undergo in a reduced gravity environment while also understanding bubble formation.

Electrolysis on Earth is typically done with water, but why stop there? The team used their CFD to model two other liquids that might be used in electrolyzers – molten salt (MSE) and molten regolith (MRE). Molten salt is used on Earth, but less commonly than regular water, and has successfully produced oxygen. However, molten regolith electrolysis is still somewhat of a novel use case and has yet to be thoroughly tested. MOXIE, the experiment that famously created oxygen on Mars in 2021, used the carbon dioxide in Mars’ atmosphere and a solid-state electrode – neither representative of molten regolith.

Fraser discusses MOXIE electrolysis with Dr. Michael Hect.

Dr. Burke and his team found that, computationally, at least, MRE has the most challenging conditions in reduced gravity. It has also never been tested in any reduced gravity environment, so for now; these simulations are all engineers have to go on with if they are going to design a system.

There were a few key takeaways from the modeling, though. First, engineers should design horizontal electrodes into MRE systems, as the longer a bubble spreads across an electrode (i.e., as it goes “up” it), the longer it takes for that bubble to detach. In a horizontal configuration, the electrode has less surface area to attach to, making it more likely for the bubbles to detach and float to the surface.

Additionally, the amount of time bubbles remain attached to an electrode scales exponentially with decreasing gravity. That means bubbles on the Moon will take longer to detach than those on Mars, which will take longer than those on Earth. Consequently, electrolysis on the Moon will be less efficient than that on Mars, which will again be less efficient than that on Earth, and mission planners will need to account for these discrepancies if they plan on getting something as mission-critical as oxygen from this process. The smoothness of the electrodes also seems to matter, with rougher electrodes more likely to hold onto their bubbles and, therefore, end up less efficient.

SciShow Space explores the world of MRE.
Credit – SciShow Space YouTube Channel

Other engineering solutions can overcome all these challenges, such as a vibratory mechanism on the electrode to shake the bubbles loose. However, it’s a good idea to consider all the additional complications operations in a reduced gravity environment have before launching a mission. That’s why modeling is so important, but humanity will ultimately have to experimentally test these systems, perhaps on the Moon itself, if we plan to utilize its local resources to sustain our presence there.

Learn More:
Burke et al. – Modeling electrolysis in reduced gravity: producing oxygen from in-situ resources at the moon and beyond
UT – NASA Wants to Learn to Live Off the Land on the Moon
UT – What is ISRU, and How Will it Help Human Space Exploration?
UT – A Robotic Chemist Could Whip up the Perfect Batch of Oxygen on Mars

Lead Image:
Graphic showing the difference in bubble accumulation in low and high gravities.
Credit – Burke et al.

The post Producing Oxygen From Rock Is Harder In Lower Gravities appeared first on Universe Today.

It would be tricky to burn away the outer layers of Uranus, but doing so could reveal a possible stash of gems – in this episode of Dead Planets Society, the hosts reveal a relatively simpler technique to rob the ice giant

Efficient solar panels have helped make solar power the cheapest form of energy on the planet, and new designs based on space-age technology are going further

Why July 2024 is a prime time to see distant Pluto before it fades from view.

Lots of the ‘wow factor’ in astronomy revolves around knowing just what you’re seeing. Sure, a quasar might be a faint +14th magnitude point of light seen at the eyepiece, but it’s also a powerful energy source from the ancient Universe, billions of light-years distant.

The same case is true for finding Pluto. Though its 0.1” disc won’t resolve into anything more than a speck in even the most powerful backyard telescope, knowing just what you’re seeing is part of the thrill of finding the distant world.

Pluto in 2024

The good news is, Pluto reaches opposition for 2024 this week on July 23rd. This means it rises when the Sun sets, and is highest in the sky and well-placed for observation around midnight. 2024 sees Pluto loitering in the zodiacal constellation of Capricornus the Goat, just across the border from its former decade-long residence in Sagittarius.

A wide field finder chart for Pluto in July 2024. Credit: Stellarium

Fun fact: on a leisurely 248-year orbit, Pluto has only moved from the constellation Gemini where it was first discovered by astronomer Clyde Tombaugh in 1930, to its present position.

At the eyepiece, Pluto presents a +14th magnitude dot. You’ll have to star hop through the dense star field to locate the distant world. Sketching or photographing the region to cinch the sighting. Your watching for the slight but discernible motion of the world from one night to the next. Heavens-Above can give you the right ascension/declination search coordinates for Pluto for a given night.

The path of Pluto through late July into August. Stars are plotted down to +14th magntude. Credit: Starry Night.

I remember showing off Pluto to viewers at the Flandrau Observatory in Tucson with the 14” telescope… the world was an easy catch, even from bright downtown urban skies. Use a 6” or larger aperture telescope in your quest.

A Receding World

Pluto passed perihelion on September 5th, 1989. It is now headed out to a distant aphelion 49.3 Astronomical Units (AU or 7.4 billion kilometers) from the Sun next century in February 2114. This means that Pluto varies in brightness from an apparent magnitude of +13.7 near perihelion, to 16 times fainter at magnitude +16.3 near aphelion. Clyde was fortunate that Pluto was headed towards perihelion in the mid-20th century. Otherwise, it might well have eluded discovery (!) Pluto is getting successively fainter with each opposition in the 21st century, so the time to see it for yourself is now.

Pluto from 2016. Credit: Sharin Ahmad From a Dot to a World

Until less than a decade ago, we knew of Pluto’s brightness, distance and orbit… and not much else. One inside joke among astronomers was that Pluto’s size and mass estimates were shrinking at such a rapid rate, that by 1980 it would disappear altogether (spoiler alert: it didn’t). Charon was discovered by astronomer James Christy as a fuzzy blob peeking out from behind its parent body in images. The large moon was found using the 61-inch telescope at the Flagstaff Observatory in 1978. Since then, Hubble revealed four more moons, named Styx, Nix, Kerberos and Hydra.

At +16th magnitude, Charon should be in range of a large dedicated amateur telescope. To date, I’ve only ever seen one convincing potential capture of the large moon. Orbiting once every six days, Charon reaches a separation of about 1”… certainly, near opposition is a key time to try and carry out this extremely challenging observation. Bizarre fact: if astronauts make it to the surface of Pluto by 2107 AD, they can witness a cycle of solar eclipses, courtesy of Charon.

NASA’s New Horizons really opened up the frontier on Pluto and its moons during its historic flyby in 2015. The mission revealed the worlds in dramatic detail. Nearly a decade later, new research is still coming out on the results from the flyby. We now live in an era where we can discuss the formation of Charon, or the geology of Pluto…

New Horizons’ view of Pluto. Credit: NASA/APL/New Horizons

Good luck, on your quest to cross Pluto off of your astronomical life list.

The post Astro-Challenge: Catching Pluto at Opposition 2024 appeared first on Universe Today.

The slow-running movement, in which people meet for unhurried jogs, is booming – but don't be fooled into thinking that if there's no pain, there's no gain

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Chemists have developed a rapid electrothermal mineralization (REM) process, which in seconds can remediate the accumulation of synthetic chemicals that can contaminate soil and the environment.

A pilot study shows that nanoscopic 3-D imaging of ancient bone not only provides further insight into the changes soft tissues undergo during fossilization, it also has potential as a fast, practical way to determine which specimens are likely candidates for ancient DNA and protein sequence preservation.

Faced with the world's impending freshwater scarcity, researchers turned to solar steam generators, which are emerging as a promising device for seawater desalination. The team sought design inspiration from trees and harnessed the potential of 3D printing. They present technology for producing efficient SSGs for desalination and introduces a novel method for printing functional nanocomposites for multi-jet fusion. Their SSGs were inspired by plant transpiration and are composed of miniature tree-shaped microstructures, forming an efficient, heat-distributing forest.

Researchers have developed a low-cost, flexible, and customizable sensor for badminton players that overcomes current monitoring constraints. The team used triboelectric sensors to construct their intelligent monitoring system because they are easy to adapt for flexible, wearable devices and to minimize interference during bending and twisting, they built a 3D-printed flexible arch-shaped sensor encased in a thermoplastic elastomer. This design is comfortable during use and can be easily customized to individual athletes.

In the crowded urban landscape, where small electric vehicles -- primarily scooters and bicycles -- have transformed short distance travel, researchers are reporting a major national surge in accidents tied to 'micromobility.'

Researchers have published new research that reports on a potential alternative and less-invasive approach to measure intracranial pressure (ICP) in patients.

Scientists use a multimodal approach that combines hard X-ray computed tomography and X-ray fluorescence imaging to see the structure and chemical processes inside of a single cell.

New research has revealed critical insights into how strategic emission cap choices can lead to cost-effective, near-100% ammonia industry decarbonization while avoiding issues such as land use constraints and grid congestion.

Researchers found that an artificial intelligence (AI) model solved medical quiz questions -- designed to test health professionals' ability to diagnose patients based on clinical images and a brief text summary -- with high accuracy. However, physician-graders found the AI model made mistakes when describing images and explaining how its decision-making led to the correct answer.

A new study shows that over half of the medicines stocked in space -- staples such as pain relievers, antibiotics, allergy medicines, and sleep aids -- would expire before astronauts could return to Earth.

A room-temperature method to decompose perfluoroalkyl substances (PFASs) using visible LED light offers a promising solution for sustainable fluorine recycling and PFAS treatment.