The HiRISE camera orbiting Mars spotted 269 of these beautiful coils on the surface of the Athabasca Valles Region of the Red Planet. The patterns, which range from 15 to more than 90 feet wide, seem to be larger versions of those sometimes observed on Earth after a volcanic eruption; they can arise when two lava flows going in opposite directions curl around each other, or when the molten lava rotates slowly because of differences in the density or viscosity of two intersecting flows. There has been debate among scientists over whether the region’s unusually patterned surface was formed by ice or lava, and the publication of these images in this week’s Science adds credence to the lava theory.
Image courtesy of NASA/JPL/University of Arizona
An image of the Martian surface from NASA’s Viking 2
To eke out even the barest subsistence on Mars, a living thing would have to adapt to a formidable set of environmental challenges: an arid, often extremely cold landscape with miniscule amounts of oxygen in the atmosphere and no organic matter to eat. During a recent foray into a similarly inhospitable part of our own planet, scientists have discovered several species of bacteria that hint at what life on Mars, if it exists, might look like. These microbes survive on minerals in the surrounding rocks—minerals also found in the Martian surface.
What’s the News: If you were to bring a glass of water to Mars, the liquid would instantly boil because the Red Planet’s carbon dioxide atmosphere is so thin: The vapor pressure of the water easily surpasses the weak atmospheric pressure, sending water molecules flying off quickly into the atmosphere. However, ancient shorelines and river-like features indicate that Mars had a watery past, leading researchers to wonder what happened to Mars’ once-thicker atmosphere. Now, data from the Mars Reconnaissance Orbiter has uncovered a massive deposit of solid CO2 at the south pole that could double the planet’s atmospheric pressure if it were released as gas. “If you double the amount of CO2 in the atmosphere, it’s quite possible that you could have liquid water,” planetary scientist Philip James of the Space Science Institute in Boulder told Scientific American. “People have suggested that this could happen, and now it looks like it could be possible.”
Humankind’s experience visiting worlds beyond our own begins and ends with the dozen Apollo astronauts who skipped about on tiny swaths of the moon. But that doesn’t mean we can’t experiment with how and where we might visit (or live) on the extreme surfaces of other worlds. A few studies out recently are doing just that.
Radiation? Big deal
Our planet provides a protective shield from the most damaging radiation produced by the sun—a shield not available on the moon or Mars. It’s a hazard for any human leaving the planet, and it’s a hazard for plants, too.
However, a new study of the Chernobyl area in the Ukraine, site of the famous nuclear accident, is actually raising hopes for space farming.
Even 25 years after the catastrophic nuclear accident at Chernobyl, the area around the site harbors radioactive soil. But researchers working there have found that oil-rich flax plants can adapt and flourish in that fouled environment with few problems. Exactly how the flax adapted remains unclear, but what is clear is that two generations of flax plants have taken root and thrived there, and that could have big implications for growing plants aboard spacecraft or on other planets at some point in the future. [Popular Science]
Across the far northern regions of Mars, a sea of dunes dots the red landscape, continuing on for thousands of miles. At first glance they appear like fossils of geography—reminders of a time when Mars was vivacious and windswept that now find themselves encrusted and stationary.
Looks can be deceiving. A research team confirms in Science this week that Mars’ dunes are not static. Atmospheric processes forged by the turning of Mars‘ seasons cut into the dunes and send sand flying about. Scientists just couldn’t see it before.
“I was hoping for tiny little changes to be detectable,” planetary scientist Candice Hansen-Koharcheck with the Planetary Science Institute in Tucson, Ariz., [said]. “This was more like knock-your-socks-off kind of stuff. It’s a very active part of the Mars landscape in today’s climate.” [Discovery News]
Hansen-Koharcheck turned the HiRISE camera of the NASA Mars Reconnaissance Orbiter on the dunes, and recorded for two Martian years (four Earth years or so). Earlier HiRISE pictures suggested that the dunes were not unchanging. These new images show not only that the dunes of Mars are a dynamic place, but, according to the team, that the forces pushing their evolution are not seen on our planet.
The plucky rovers Spirit and Opportunity and the ice-finding Phoenix Lander have perhaps drawn more attention, but it’s the craft that’s been in steady, silent orbiter that has them all beat for longevity. The Mars Odyssey mission just clicked off its 3,340th day in orbit of Mars yesterday, making it the longest-running human mission to the Red Planet. The Mars Global Surveyor, another orbiter, held the record previously.
At this point, after finding microorganisms that don’t mind extreme temperatures, pressure, aridity and other hardships, we shouldn’t be surprised that bacteria‘s dominion over the Earth extends to just about anywhere we look. A new expedition to the Earth’s crust has reached unprecedented depths—down to the deepest layer of the crust—and found that even there, microorganisms are tough enough to survive.
On a hypothetical journey to the centre of the Earth starting at the sea floor, you would travel through sediment, a layer of basalt, and then hit the gabbroic layer, which lies directly above the mantle. Drilling expeditions have reached this layer before, but as the basalt is difficult to pierce it happens rarely. [New Scientist]
To circumvent the Herculean task of drilling through basalt, the expedition, called the Integrated Ocean Drilling Programme, headed out to sea to find an easier drilling location.
The Integrated Ocean Drilling Program sank its drill into the Atlantis Massif (seen above) in the central Atlantic Ocean where seismic forces have pushed the deep layer, known as the gabbroic layer, to within 230 feet of the ocean floor making it easier to reach. [UPI]
The British team that described its design in the journal Proceedings of the Royal Society A isn’t the first to suggest a hopper. But unlike previous designs, this hopper wouldn’t rely on solar power for fuel, but would instead by powered by radioactive isotopes and the plentiful carbon dioxide in Mars’s atmosphere.
The ability to hop from place to place would enable the new explorers to cover more of the Martian landscape, and visit rough terrain that earlier rovers couldn’t handle. The 2004 rover Opportunity is just hitting 15 miles of surface driving after almost seven years on Mars.
Dr Richard Ambrosi [who worked on the project], at the Leicester Space Research Centre, commented: “The improved mobility and range of a hopping vehicle will tell us more about the evolution of Mars and of the Solar System and may answer questions as to whether there was life in the past, whether Mars was wetter in the past and if so where that water went.” [Press Release]
The Martian rovers and orbiters have sent so much data back to Earth in the last few years that discoveries about Mars’ wet and active past come left and right. Yesterday we covered the story that the stuck Spirit rover may have found evidence of recent water right under its tracks. And another study this week, out in Nature Geoscience, pinpoints a spot by a Mars volcano that could contain evidence of a watery system more than 3 billion years old—and perhaps even life, too.
The finding came after the Mars Reconnaissance Orbiter observed a mineral called hydrated silica sitting on the flank of the extinct Syrtis Major volcano.
The mineral is transported and then concentrated by hot water or steam, suggesting the deposits were laid down in what was once a hydrothermal environment. Groundwater may have been heated by magma from the erupting volcano and vented to the surface as steam, says John Mustard of Brown University in Rhode Island, a member of the team that identified the mineral. [New Scientist]
Spirit just can’t help itself. Even stuck in a sand trap from which it will never escape, the Mars rover finds clues that reveal more about the nature of Mars and the water cycle on the Red Planet.
It was earlier this year that NASA gave up on freeing Spirit: With a broken wheel, the rover simply could not extricate itself from the loose terrain that ensnares it. But as the rover team drove Spirit back and forth, it dug deeper and deeper into the Martian ground. Says team member Ray Arvidson:
“We’re driving backwards, the right front wheel doesn’t work, so wherever we went we had to drag it along. It’s like pushing a shopping cart with a bad front wheel. You don’t push it, you pull it, but the wheel has torque.” [Discovery News]