On Mars, massive ice sheets — not rivers — may have carved ancient valleys - Space.com

Early Mars may not have been quite the warm, wet paradise scientists have hoped for — not if the valleys scarring its surface work the same way as their counterparts here on Earth do.

That's the conclusion of new research that tried to suss out what the Red Planet really looked like during its first billion years by analyzing more than 10,000 segments of valleys on Mars.

According to the new analysis, some Martian valleys may have been formed by a similar process to those lurking below Devon Island's ice.

"Mars is similar, in that valleys look very different from each other, suggesting that many processes were at play to carve them.".

That sort of erosion produces a different valley pattern than one generated by a free-flowing river, according to the scientists, and many of the Martian valleys they studied seem to be a better match for that ice sheet formation model.

According to that analysis, 22 of the 66 networks evaluated best match the patterns formed by meltwater running under a glacier, the researchers concluded.

Another nine best match patterns formed by glaciers themselves, whereas 14 best match patterns formed by rivers.

The researchers also found that the valleys that looked like they were formed by meltwater running beneath glaciers were spread across Mars, while those that looked to have been formed by rivers were concentrated around Arabia Terra, a particularly old region of Mars, according to NASA.