Mud volcanoes on Mars hint at ancient water reservoirs
Arsia Mons once spewed molten rock across the surface of Mars, but some smaller volcanic features may have come from another source. (NASA/JPL/USGS/)Mars’s northern lowlands are dotted with tens of thousands of what appear to be run-of-the-mill volcanoes, given the lava-like ripples and fingers that appear around them. But geologists debate whether these bumpy landforms are really frozen magma. In a select few places on Earth, mud erupts rather than molten rock. Could Martian orbiters be sending back pictures of mud volcanoes? Absolutely not, assumed Petr Brož, a geophysicist at the Czech Academy of Sciences. The circumstances required—sediments buried in precisely the right way—were just too unlikely. Plus, would mud even slosh after hitting the frigid surface? After recreating the scenario in a lab, Brož and his team now have their answer: Muddy mixtures on Mars would flow nearly identically to the way lava flows on Earth, although for completely...