Mars averages minus 80 degrees Fahrenheit. That's nowhere near the boiling point of water, 212 degrees Fahrenheit. But the pressure on Mars is much lower than it is on Earth, which also means the boiling point of water is lower on Mars than it is on Earth.
Scientists shocked the world in September 2015 when they confirmed liquid water flows on Mars. Dark streaks that appear on the hills of Mars every summer are evidence of that water:
But scientists still aren't sure how the water is carving out such deep channels in the soil.
That's where the boiling-water theory comes in. Boiling water would be capable of creating trenches and moving sediment around.
A team of researchers tested the theory by creating a simulated Mars environment in their lab to test the theory. The put a block of ice at the top of a sandy slope and exposed it to the low pressure that Mars has. The water boiled and rolled down the slope, carving out shallow trenches and leaving behind dark streaks:
You can see how the water flow changes in conditions on Earth compared to conditions on Mars. On Earth, the water just melts and rolls down the hill. On Mars, it boils and carves its way down:
One big takeaway from the study: Only a small amount of water is required to create these streaks, so there might be less water on Mars than previously thought. And if the water is boiling, it may only exist on the surface for a very short amount of time before evaporating.
Less water and quickly disappearing water is a blow to the theory that life may exist (or did exist) on Mars, Popular Science reports.
But either way, we just got one step closer to understanding the mysterious water cycle on Mars.
h/t Popular Science