Dark/Light Blotches
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by
Ella7777
In this photo, there seem to be light and dark areas. Would I mark the light areas as blotches/fans, or the dark areas? It looks like the light areas should be blotches, based on the way they look, but none of the examples I looked at showed light colored blotches.
Thanks!Posted
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by
p.titchin
Hi Ella. This is the largely defrosted surface of the area we call "Ithaca".(Nov2016) So, no ice sheet, so no venting. I think the lighter patches are remaining traces of frost. The Mars year is 686.9 Earth days, so you cannot match the seasons here with Mars, but the Southern polar ice cap shrinks a lot in the Mars southern Summer. It is this "thaw" every 1.8 years that produces the CO2 sublimation that leads to the gas venting onto the surface through cracks and weaknesses and causing the plumes of frost and dust that lead to the "blotches" and "fans". Hope this is a help. Good to see a new name on the ddiscussion pages. Hope to see you on them again ~pete.
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