The dwarf planet Ceres -- long believed to be a barren space rock -- is an ocean world with reservoirs of sea water beneath its surface, the results of a major exploration mission showed on Monday. The Guardian reports: Ceres is the largest object in the asteroid belt between Mars and Jupiter and has its own gravity, enabling the Nasa Dawn spacecraft to capture high-resolution images of its surface. Now a team of scientists from the United States and Europe have analyzed images relayed from the orbiter, captured about 35km (22 miles) from the asteroid. They focused on the 20-million-year-old Occator crater and determined that there is an "extensive reservoir" of brine beneath its surface.

Using infrared imaging, one team discovered the presence of the compound hydrohalite -- a material common in sea ice but which until now had never been observed off of Earth. Maria Cristina De Sanctis, from Rome's Istituto Nazionale di Astrofisica said hydrohalite was a clear sign Ceres used to have sea water. "We can now say that Ceres is a sort of ocean world, as are some of Saturn's and Jupiter's moons," she told AFP. The team said the salt deposits looked like they had built up within the last 2 million years -- the blink of an eye in space time. This suggests that the brine may still be ascending from the planet's interior, something De Sanctis said could have profound implications in future studies.

Writing in an accompanying comment article, Julie Castillo-Rogez, from the California Institute of Technology's Jet Propulsion Laboratory, said the discovery of hydrohalite was a "smoking gun" for ongoing water activity. "That material is unstable on Ceres' surface, and hence must have been emplaced very recently," she said. In a separate paper, US-based researchers analyzed images of the Occator crater and found that its mounds and hills may have formed when water ejected by the impact of a meteor froze on the surface.

NASA is heading back to the Red Planet. The agency launched a new rover, a car-size robotic explorer named Perseverance, to Mars on an ambitious mission to scour the planet for evidence of ancient life. From a report: The rover, which launched into orbit Thursday at 7:50 a.m. ET, is designed to study the geology and climate of Mars. NASA says the mission and its subsequent discoveries could lay the groundwork for eventual human exploration of the Red Planet. Perseverance is loaded with seven scientific instruments to explore the Martian landscape and assess whether the planet was ever able to sustain life. The six-wheel rover is also carrying a small helicopter, dubbed Ingenuity, to perform experimental test flights in Mars' thin atmosphere, which, if successful, would mark a milestone in powered flight.

"For the first time ever, we're going to fly a helicopter on another planet," NASA Administrator Jim Bridenstine said Monday in a news briefing, adding that future missions to other worlds could use similar helicopters as airborne scouts. The Perseverance rover launched aboard an Atlas V rocket from Cape Canaveral Air Force Station in Florida. Typically, crowds gather along beaches near Cape Canaveral to witness NASA launches, but because of the coronavirus pandemic, the agency encouraged space fans to stay home and participate virtually, instead -- particularly as new infections continue to surge in Florida and across the country. Matt Wallace, the mission's deputy project manager at NASA's Jet Propulsion Laboratory in Pasadena, California, said the rover has already lived up to its name, as engineers persevered through the pandemic to ready the spacecraft for its much-anticipated launch. "Nothing prepared us for what we had to deal with in the middle of March as the pandemic struck -- not just our team, but communities across the country and the world," Wallace said. "At that point in the mission, we were in our final assembly activities."

Airbus-France will build the huge satellite that brings the first Martian rock samples back to Earth. The BBC reports: This material will be drilled on the Red Planet by the US space agency's next rover, Perseverance, before being blasted into orbit by a rocket. It'll be the Airbus satellite's job to grab the packaged samples and then ship them home. The joint American-European project is expected to cost billions and take just over a decade to implement. But scientists say it's probably the best way to confirm whether life has ever existed on the Red Planet. Any evidence is likely to be controversial and will need the powerful analytical tools only found in Earth laboratories to convince the doubters, the researchers argue.

The Airbus satellite will be a Goliath among spacecraft. The Earth Return Orbiter (ERO) will weigh 6.5 tonnes at launch in 2026 and use a mix of chemical and electric propulsion to get to Mars, orbit the planet and then return to Earth with its rock consignment. Thales Alenia Space of Italy will be a lead subcontractor working on this aspect of the design. The inclusion of a powerful ion engine will require a lot power, hence the use of immense solar arrays. These panels will give the satellite a "wingspan" of 39m, more than 120ft. But the really remarkable facet of the satellite's mission is the game of catch it will have to play high above Mars. Nasa will put a rocket on the planet later this decade to fire the rocks collected by Perseverance into orbit. The Airbus spacecraft will have to manoeuvre itself into a position to capture these samples that will be packaged inside a football-sized container. After ingesting this container, the satellite must then prepare it for return to Earth. "This is not just twice as difficult as any typical Mars mission; it's twice squared - when you think about the complexity involved," said Dr David Parker, the director of human and robotic exploration at the European Space Agency (Esa). "And this satellite that Airbus will build -- I like to call it 'the first interplanetary cargo ship,' because that's what it will be doing. It's designed to carry cargo between Mars and Earth," he told BBC News.

A tiny piece of Martian basalt the size of a 10p coin will be launched on board a U.S. robot probe on Thursday and propelled towards the red planet on a seven-month journey to its home world. The Guardian reports: This extraordinary odyssey, the interplanetary equivalent of sending coals to Newcastle, will form a key part of Nasa's forthcoming Mars 2020 expedition. Space engineers say the rock -- which has been donated by the Natural History Museum in London -- will be used to calibrate detectors on board the robot rover Perseverance after it lands and begins its search for signs of past life on the planet. "When you turn on instruments and begin to tune them up before using them for research, you calibrate them on materials that are going to be like the unknown substances you are about to study. So what better for studying rocks on Mars than a lump that originated there?" said Professor Caroline Smith, the Natural History Museum's principal curator of meteorites.

Scientists were confident that the rock they were returning to Mars originated on the planet, added Smith, who is also a member of the Mars 2020 science team. "Tiny bubbles of gas trapped inside that meteorite have exactly the same composition as the atmosphere of Mars, so we know our rock came from there." It is thought that the Martian meteorite was created when an asteroid or comet plunged into the planet about 600,000 to 700,000 years ago, spraying debris into space. One of those pieces of rubble swept across the solar system and eventually crashed on to Earth. That meteorite -- now known as SAU 008 -- was discovered in Oman in 1999 and has been in the care of the Natural History Museum since then.

Among the instruments fitted to the Perseverance rover is a high-precision laser called Sherloc, which will be used to decipher the chemical composition of rocks and determine if they might contain organic materials that indicate life once existed -- or still exists -- on Mars. The inclusion of a piece of SAU 008 is intended to ensure this is done with maximum accuracy. Once Perseverance has selected the most promising rocks it can find, it will dump them in caches on the Martian surface. These will then be retrieved by subsequent robot missions and blasted into space towards Earth for analysis.

Humans on the moon and Mars would face the problem of damaging space radiation.

But new research suggests one possible solution to the fact that "Space wants to kill you," according to CNET: To protect astronauts, scientists have been studying an unusually hardy organism, discovered in one of the most radioactive places on the planet: Chernobyl... In some parts of the plant, the level of radiation spiked so high that exposure would kill a human in about 60 seconds. But several species of fungi have been discovered in the reactor. And they're thriving, "feeding" on the extreme levels of radiation. A new study, yet to undergo peer review, was published on the pre-print repository bioRxiv on July 17 and examines one of these species, Cladosporium sphaerospermum. It suggests the fungi could be used as a self-healing, self-replicating shield to protect astronauts in deep space...

Researchers placed the fungi aboard the ISS for 30 days and analyzed its ability to block radiation... The proof-of-concept study showed that the fungi was able to adapt to microgravity and thrive on radiation. It was able to block some of the incoming radiation, decreasing the levels by almost 2%. One of the major advantages, the researchers write, is the fungi self-replicates from microscopic amounts. You would only need to send a small amount to orbit, give it some nutrients and let it replicate, forming a biological radiation shield. With some tweaking, the fungi could be used to shield bases on the moon or Mars.

It's a long while until we put boots on the red planet, but the groundwork is being laid now.

"The U.S. wants to build nuclear power plants that will work on the moon and Mars, and on Friday put out a request for ideas from the private sector on how to do that," reports Time magazine: The U.S. Department of Energy put out the formal request to build what it calls a fission surface power system that could allow humans to live for long periods in harsh space environments.

The Idaho National Laboratory, a nuclear research facility in eastern Idaho, the Energy Department and NASA will evaluate the ideas for developing the reactor. The lab has been leading the way in the U.S. on advanced reactors, some of them micro reactors and others that can operate without water for cooling. Water-cooled nuclear reactors are the vast majority of reactors on Earth. "Small nuclear reactors can provide the power capability necessary for space exploration missions of interest to the Federal government," the Energy Department wrote in the notice published Friday...

The goal is to have a reactor, flight system and lander ready to go by the end of 2026... Officials say operating a nuclear reactor on the moon would be a first step to building a modified version to operate in the different conditions found on Mars.

"Researchers have spotted large waves of martian sand migrating for the first time," reports Science magazine.

"The discovery dispels the long-held belief that these 'megaripples' haven't moved since they formed hundreds of thousands of years ago. They're also evidence of stronger-than-expected winds on the Red Planet." It's pretty staggering that humans can detect these changes on Mars, says Ralph Lorenz, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory who was not involved in the research. "We can now measure processes on the surface of another planet that are just a couple times faster than our hair grows...."

Since the early 2000s, Mars rovers and orbiters have repeatedly spotted megaripples on the Red Planet. But they didn't seem to change in any measurable way, which led some scientists to think they were relics from Mars's past, when its thicker atmosphere permitted stronger winds. Now, using images captured by NASA's Mars Reconnaissance Orbiter, Simone Silvestro, a planetary scientist at Italy's National Institute of Astrophysics in Naples, and his colleagues have shown that some megaripples do creep along — just very slowly. The researchers focused on two sites near the equator of Mars... Megaripples in both regions advanced by about 10 centimeters per year, the team reports in the Journal of Geophysical Research: Planets...

It's a surprise that megaripples move at all on Mars, says Jim Zimbelman, a planetary geologist at the Smithsonian Institution's Air and Space Museum. Just a few decades ago, there was no evidence that sands on Mars were mobile, he says. "None of us thought that the winds were strong enough...." Atmospheric models of Mars suggest winds capable of moving sand are rare. This discovery of migrating megaripples will force those models to be revised, the team suggests....

Megaripples on the move are beacons of windy conditions, which might in turn kick-start dust storms, the researchers suggest. Airborne dust can blanket solar panels, reducing their efficiency, and it can also gum up mechanical parts like gears. That's bad news for Mars rovers and human habitats alike.

AmiMoJo shares a report from the BBC: China has launched its first rover mission to Mars. The six-wheeled robot, encapsulated in a protective probe, was lifted off Earth by a Long March 5 rocket from the Wenchang spaceport on Hainan Island at 12:40 local time (04:40 GMT). It should arrive in orbit around the Red Planet in February. Called Tianwen-1, or "Questions to Heaven," the rover won't actually try to land on the surface for a further two to three months. This wait-and-see strategy was used successfully by the American Viking landers in the 1970s. It will allow engineers to assess the atmospheric conditions on Mars before attempting what will be a hazardous descent. Tianwen-1 is one of three missions setting off to Mars in the space of 11 days. On Monday, the United Arab Emirates (UAE) launched its Hope satellite towards the Red Planet. And in a week from now, the U.S. space agency (Nasa) aims to despatch its next-generation rover, Perseverance.

The first Arab space mission to Mars has blasted off aboard a rocket from Japan, with its unmanned probe -- called Al-Amal, or Hope -- successfully separating about an hour after liftoff. The Guardian reports: The Emirati project is one of three racing to Mars, including Tianwen-1 from China and Mars 2020 from the United States, taking advantage of a period when the Earth and Mars are nearest. In October, Mars will be a comparatively short 38.6m miles (62m km) from Earth, according to Nasa. Hope is expected to reach Mars's orbit by February 2021, marking the 50th anniversary of the unification of the UAE, an alliance of seven emirates. Unlike the two other Mars ventures scheduled for this year, it will not land on the planet, but instead orbit it for a whole Martian year, or 687 days.

While the objective of the Mars mission is to provide a comprehensive image of the weather dynamics in the red planet's atmosphere, the probe is a foundation for a much bigger goal -- building a human settlement on Mars within the next 100 years. The UAE also wants the project to serve as a source of inspiration for Arab youth, in a region too often wracked by sectarian conflicts and economic crises. On Twitter, the UAE's government declared the probe launch a "message of pride, hope and peace to the Arab region, in which we renew the golden age of Arab and Islamic discoveries."

The United Arab Emirates has successfully launched a spacecraft towards an orbit around Mars, reports the New York Times. Built by a space physics lab at the University of Colorado, the Hope Mars probe was tested in Dubai, before being shipped to Japan's Tanegashima Island, where it was launched by Mitsubishi Heavy Industries. The launch is being streamed on the web and on YouTube. It will join a fleet of six other spacecrafts studying the red planet from space, three operated by NASA, two by the European Space Agency (one shared with Russia) and one by India. Each contains different instruments to help further research of the Martian atmosphere and surface.

The Hope orbiter is carrying three instruments: an infrared spectrometer, an ultraviolet spectrometer and a camera. From its high orbit — varying from 12,400 miles to 27,000 miles above the surface — the spacecraft will give planetary scientists their first global view of Martian weather at all times of day. Over its two-year mission, it will investigate how dust storms and other weather phenomena near the Martian surface have either speed or slow the loss of the planet's atmosphere into space.
"You'll be hearing a lot about Mars this summer," the Times adds. "Three missions are launching toward the red planet, taking advantage of the way Earth and its neighbor get closer every 26 months or so, allowing a relatively short trip between the two worlds." The next expected launch will be China's Tianwen-1, which could occur between later this week through early August... On July 30, NASA is scheduled to launch Perseverance, a robotic rover that will be the fifth wheeled American vehicle to explore Mars... A fourth mission, the joint Russian-European Rosalind Franklin rover, was to launch this summer, too. But technical hurdles, aggravated by the coronavirus pandemic, could not be overcome in time to meet the launch window. It is now scheduled to launch in 2022.
If the other three spacecraft all launch successfully, they should arrive at Mars early next year.

Long-time Slashdot reader sjritt00 writes: A final collection of Terry Pratchett's early stories will be published in September as The Time-Travelling Caveman. These stories appeared in the Bucks Free Press and Western Daily Press in the 1960s and early '70s and introduce many of the themes which later power his Discworld series.
The Guardian reports that the stories "range from a steam-powered rocket's flight to Mars to a Welsh shepherd's discovery of the resting place of King Arthur."

In a statement Pratchett's editors said "It is very fitting that some of the first stories he wrote will be in the last collection by him to be published..."

schwit1 shares a report from UPI: The most popular theory of the moon's origins contends the satellite was formed when a Mars-sized object collided with Earth, vaporizing large portions of Earth's upper crust. While Earth's upper crust is poor in metals, new research -- published Wednesday in the journal Earth and Planetary Science Letters -- suggests the moon's subsurface is surprisingly metal-rich, undermining the satellite's proposed origin story. Authors of the new study suggest planetary scientists consider alternative theories for the moon's formation.

It's possible the collision that forged the moon was more violent than scientists thought, gouging out even deeper portions of Earth's crust and mantle. It's also possible the moon experienced an unusual cool-down process, post-collision -- a process that left the moon with large concentrations of metal.

Oracle's Java magazine is celebrating the 25th anniversary of the programming language with a list of the 25 greatest Java apps ever written: From space exploration to genomics, from reverse compilers to robotic controllers, Java is at the heart of today's world. Here are a few of the countless Java apps that stand out from the crowd.

The story of Java began in 1991, at a time when Sun Microsystems sought to extend their lead in the computer workstation market into the burgeoning personal electronics market. Little did anyone know that the programming language Sun was about to create would democratize computing, inspire a worldwide community, and become the platform for an enduring software development ecosystem of languages, runtime platforms, SDKs, open source projects, and lots and lots of tools. After a few years of secret development led by James Gosling, Sun released the landmark "write once, run anywhere" Java platform in 1995, refocusing it beyond its original design for interactive television to applications for the burgeoning World Wide Web. By the turn of the century, Java was animating everything from smartcards to space vehicles.

Today, millions of developers program in Java. Although Java continues to evolve at an ever-faster pace, on the occasion of the platform's 25th anniversary, Java Magazine decided to take a look back at how Java molded our planet. What follows is a list of the 25 most ingenious and influential Java apps ever written, from Wikipedia Search to the US National Security Agency's Ghidra. The scope of these applications runs the gamut: space exploration, video games, machine learning, genomics, automotive, cybersecurity, and more.
The list includes Eclipse, Minecraft, the Maestro Mars Rover controller, and "VisibleTesla," the open source app created by an automobile enthusiast to monitor and control his Tesla Model S.

As part of NASA's next mission to Mars, leaving Earth this summer, the space agency will attempt to do something that has never been done before: fly a helicopter through the rarefied atmosphere of Mars. The New York Times reports: If it works, the small helicopter, named Ingenuity, will open a new way for future robotic explorers to get a bird's-eye view of Mars and other worlds in the solar system. "This is very analogous to the Wright brothers moment, but on another planet," said MiMi Aung, the project manager of the Mars helicopter at NASA's Jet Propulsion Laboratory over the past six years.

Flying on Mars is not a trivial endeavor. There is not much air there to push against to generate lift. At the surface of Mars, the atmosphere is just 1/100th as dense as Earth's. The lesser gravity -- one-third of what you feel here -- helps with getting airborne. But taking off from the surface of Mars is the equivalent of flying at an altitude of 100,000 feet on Earth. No terrestrial helicopter has ever flown that high, and that's more than twice the altitude that jetliners typically fly at. The copter will hitch a ride to the red planet with Perseverance, which is to be the fifth robotic rover NASA has sent there. The mission is scheduled to launch on July 20, one of three missions headed to Mars this year. At a news conference last week previewing the Perseverance mission, Jim Bridenstine, the NASA administrator, made a point to highlight Ingenuity. "I'll tell you, the thing that has me the most excited as an NASA administrator is getting ready to watch a helicopter fly on another world," he said.

Slashdot reader shirappu writes: For eight years now, the Mars Rover Curiosity has been exploring the surface of Mars. Even now, it's still exploring, and still getting upgrades. According to Tech Crunch, NASA is now looking to interested volunteers to help upgrade the rover's terrain-scanning AI systems by annotating image data of the planet itself.
"The problem is that while there are lots of ready-made data sets of images with faces, cats and cars labeled, there aren't many of the Martian surface annotated with different terrain types..." notes TechCrunch. "Improvements to the AI might let the rover tell not just where it can drive, but the likelihood of losing traction and other factors that could influence individual wheel placement."

shirappu continues: Volunteers go through a short tutorial after which they can label images to help the rover better understand the terrain on which it drives. The system is expected to be used in future planet rover robots, and the project marks an interesting example of open crowd-sourcing to improve machine learning systems, and how it is impacting technology even on other planets.

Click this link for the AI4Mars site link where people can volunteer.

Later this year, the International Space Station will receive a new and improved toilet system designed to bridge the gap between current lavatorial space tech and what humans will need to make extended visits to, say, Mars, in comfort. Space.com reports: It has a fancier name, of course; officially, the commode is NASA's Universal Waste Management System (UWMS). The launch is targeted for no earlier than the fall, a NASA spokesperson confirmed to Space.com, although the agency is still determining what spacecraft will carry the new plumbing up. The toilet currently on offer on the U.S. side of the space station was designed in the 1990s and based on its shuttle counterpart, according to a detailed review of space toiletry. But the apparatus has its flaws. It can be clunky to use, particularly for women, and it is "sensitive to crew alignment on the seat," sometimes resulting in messes, according to that review.

So NASA has tried to keep the aspects that have gotten positive reviews while trimming mass and volume and making some design changes, like adjusting the shape of the seat and replacing the apparatus that compresses the waste. Another change mimics a feature of the toilet on the Russian side of the space station, where astronauts simply hook their feet into toe bars, rather than the thigh bars used on the American equivalent to anchor the astronaut in the microgravity environment. The UWMS will remain on the space station for the rest of the orbiting laboratory's lifetime, and a second toilet of the same model will fly on the Orion capsule that astronauts use to fly around the moon on the first crewed Artemis mission in NASA's ambitious lunar return plan, according to the agency.

An anonymous reader writes: When talking about the nine year gap since America last flew astronauts with their own spacecraft, it's often said that NASA didn't have a plan in place when they retired the Space Shuttle. But the reality is a lot more complicated than that. NASA was working on a new spacecraft and rocket, and even made a successful test flight two years before the last Shuttle flight, but the program ended up getting canceled when the White House Administration changed. A review concluded that completing the program "would cost at least $150 billion dollars, and even then, a return to the Moon or a mission to Mars in the foreseeable future was unlikely," according to the article. Money was instead allocated to private alternatives like Sierra Nevada's Dream Chaser spaceplane as well as Boeing's CST-100 Starliner -- though in the end it was SpaceX's Crew Dragon which would launch the next American rocket carrying American astronauts into space. "The dark horse soundly beat the entrenched giants," the article concludes, "and the democratization of space has never been closer.

"It's hard to predict what the next decade of human spaceflight will look like, but there's no question it's going to be a lot more exciting than the previous one."

"Crew Dragon's hatch is closed, securing @AstroBehnken and @Astro_Doug in the spacecraft ahead of liftoff," SpaceX tweeted an hour ago.

Livestreaming of the launch has already begun, with liftoff scheduled in about 41 minutes.

GeekWire reports: If liftoff from NASA's Kennedy Space Center in Florida occurs today at 3:22 p.m. ET (12:22 p.m. PT), it'll be a feat that America hasn't been able to perform since NASA retired its space shuttles, nearly nine years ago. "We are going to launch American astronauts on American rockets from American soil," NASA Administrator Jim Bridenstine declared during a launch-eve briefing at the space center's countdown clock.

But even Bridenstine acknowledged that's not a sure bet for today. "Weather challenges remain with a 50% chance of cancellation," he tweeted this morning. A drenching rainstorm swept over Florida's Space Coast overnight, but the skies cleared up this morning... The launch can be scrubbed at any time, all the way down to the last second, if the weather doesn't cooperate or if a technical glitch arises. If the gumdrop-shaped Crew Dragon doesn't lift off today, Sunday is an option. The chances of acceptable weather are expected to improve to 60%. The weather outlook is even better for a June 2 backup opportunity...

Hurley and Behnken, who are both experienced shuttle astronauts, are scheduled to rendezvous with the space station on Sunday and move in alongside its current occupants, NASA's Chris Cassidy and Russia's Anatoly Ivanishin. NASA hasn't yet decided how long the Dragon riders will spend in orbit. Their stay could be as short as six weeks, or as long as 16 weeks, depending on how the test mission proceeds. For the return trip, Hurley and Behnken will strap themselves back inside the Dragon and descend to an Atlantic splashdown.

This whole flight serves as an initial demonstration of the Crew Dragon's capabilities with an actual crew aboard. If the mission is successful, yet another Crew Dragon will carry four different astronauts to the space station weeks after Hurley and Behnken return.
Reuters reporter Joey Roulette also spotted NASA astronaut Garrett Reisman by the side of the road as his fellow astronauts drove by. He was holding a sign that said "Take me with you."

And GeekWire notes that NASA Administrator Jim Bridenstine sees this event as historic. "I really think, when we look into the future, we're going to see these models of doing business with public-private partnerships apply not just to low Earth orbit... but we're taking this model to the moon and even on to Mars."

UPDATE: SpaceX just tweeted that the re-usable Falcon 9 booster rocket "has landed on the Of Course I Still Love You droneship!"

"One of the longer chapters of the International Space Station has come to a close," writes Engadget.

"NASA has sent the last of its 11 ExPRESS (Expedite the Processing of Experiments to the Space Station) science racks to the orbiting facility, 19 years after sending the first two." They don't look like much, but they provide the power, storage, climate control and communications for up to 10 small payloads — they're key to many of the experiments that run aboard the ISS and will help the station live up to its potential research capabilities. This last rack was carried aboard a Japanese cargo ship and should be installed and functioning by fall 2020. While the EXPRESS racks should be useful for a while yet, this effectively marks the end of an era for NASA's ISS work...
Originally developed by engineers at Boeing and the Marshall Space Flight Center in Alabama, "The first two completed racks were delivered to the space station on STS-100 in 2001 and have been in continuous operation ever since," notes a NASA press release, "as have all the subsequent added racks." And since then NASA has logged more than 85 total years of combined rack operational hours. "The sheer volume of science that's been conducted using the racks up til now is just overwhelming," says Shaun Glasgow, project manager for the EXPRESS Racks at Marshall.

"And as we prepare to return human explorers to the Moon and journey on to Mars, it's even more exciting to consider all the scientific investigations still to come."

The mystery of some lava-like flows on Mars has been solved by scientists who say they are caused not by lava but by mud. Phys.Org reports: There are tens of thousands of these landforms on the Martian surface, often situated where there are massive channels scoured into the surface by ancient liquids flowing downstream. These channels are extremely long, extending many hundreds of kilometers in length and usually more than dozens of kilometers wide. They are believed to be the result of massive floods involving huge bodies of water comparable to the largest floods ever known to have occurred on Earth. When the water seeps into the subsurface it can emerge again as mud.

A European team of researchers has now simulated the movement of mud on the surface of Mars, with the results published in Nature Geoscience. [...] Using the Mars Chamber at the Open University, the scientists recreated the surface temperature and atmospheric pressure on Mars as part of a simulation of conditions on both Earth and Mars. The scientists performed experiments at low pressure and at extremely cold temperatures (-20C) to recreate the Martian environment. They found that free flowing mud under Martian conditions behaves differently from on Earth, because of rapid freezing and the formation of an icy crust. This is because water is not stable and begins to boil and evaporate. The evaporation removes latent heat from the mud, eventually causing it to freeze.

Under Martian conditions, the experimental mud flows formed similar shapes to "pahoehoe" lava frequently occurring on Hawaii or Iceland on Earth, which cools down to form smooth undulating surfaces. In the experiment, this happened when liquid mud spilled from ruptures in the frozen crust, then refroze. However, under terrestrial atmospheric pressure, the experimental mud flows did not form lava shapes, did not expand, and had no icy crust, even under very cold conditions.