this post was submitted on 21 Apr 2024
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NASA's Perseverance Mars Rover

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On the plains of Jezero, the secrets of Mars' past await us! Follow for the latest news, updates, pretty pics, and community discussion on NASA and the Jet Propulsion Laboratory's most ambitious mission to Mars!

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[–] SpecialSetOfSieves 4 points 5 months ago (1 children)

The thermal cycling hypothesis for erosion has been advanced for Mars since the 1960s - before we had landed even a single mission on the surface - but personally, I'm not convinced. The effect should be ubiquitous and would apply to every clast/rock a rover can see, but just about any landscape shot shows that there are plenty of rocks without the network of cracks you'd expect. Paul Hammond is correct in pointing out that rocks preferentially fracture along planes of weakness (the direction/face where a mineral is naturally weakest), and the composition of the rocks should have a lot to do with it, but I still think that the process would be a lot further along after billions of years.

The potholes you see (...feel) in places with sub-zero winters show us exactly how good freezing/thawing water is at breaking and flaking hard surfaces, so Mars Guy isn't wrong to point that out first in the video.

[–] [email protected] 2 points 5 months ago

Maybe it’s the same process with dust acting as water on mars? It might not expand as much but with bigger temp differential maybe it’s similar?