[quote=@6slyboy6]
[@Sep]Wait, what? As in int atmosphere or in frozen form?

Cause either way it isn't a big factor tbh. Mars still needs to be terraformed.
[/quote]

In the upper atmosphere they've discovered atomic Oxygen (O, not the O[sub]2[/sub] we breath). Atomic Oxygen is highly reactive and will corrode organic material. Not something you want to come in contact with.