A simulation of a Martian day has revealed the possible cause of Mars’ extensive seasonal gullies: boiling water. The conclusion was made after researchers used Open University’s Large Mars Chamber, a steel decompression chamber equipped with simulated hills, to test the effects of water running down the surface. The gullies were first discovered in 2011, and how they formed had largely remained a mystery.
The gullies are unique, showing incremental growth and salt deposits, among other things. Because of the atmospheric conditions on the planet, water can boil at extremely low temperatures — as low as zero degrees Celsius. NASA confirmed late last year that liquid water does sometimes flow on present-day Mars, and that water, it turns out, could be forming the gullies as it boils.
Using the aforementioned simulated hills, researchers observed the effects of melted water running down a hill made of a thin layer of sand. With atmospheric levels akin to Mars, this water boiled within the sand, tossing sand down the hill into piles as it did so.
Over time, this sand pile toppled further down the hill into what appeared to be a ridge; new piles and ridges were made as the water continued to flow, finally forming what appeared to be channels with patterns similar to the gullies observed on Mars.
It doesn’t take much water to displace quite a bit of sand, the study found, but questions remain about whether the temperatures get warm enough during certain parts of the year to melt the ice — while it is possible during the Martian summer, the formation of these gullies have been observed during Mars’ seasons in which the temperature is cooler — likely too cool to melt the ice.
VIA: National Geographic