Gullies on Mars sculpted by dry ice rather than liquid water
Wednesday, December 23, 2015 - 22:40
in Astronomy & Space
Mars's gullies may be formed by dry ice processes rather than flowing liquid water, as previously thought. Scientists show that, during late winter and spring, underneath the seasonal CO2 ice layer heated by the sun, intense gas fluxes can destabilize the regolith material and induce gas-lubricated debris flows which look like water-sculpted gullies on Earth. Since 2000, the cameras in orbit around Mars have transmitted numerous images of small valleys cut into slopes, similar in shape to gullies formed by flowing water on Earth. The gullies seem less than a few million years old-and sometimes less than a few years old.