[Don Joe]

Perhaps not, but it is fa-a-ascinating to speculate.

45% oxygen?

[Aracelis]

Earth's atmosphere contains approximately 78.1% nitrogen, 20.9% oxygen, 0.9% argon and 0.1% carbon dioxide and other gases. The Martian atmosphere consists largely of carbon dioxide (~95.3%), and nitrogen (~2.7%) with minor amounts of argon, oxygen and other gases. The Martian atmosphere is said to be in equilibrium with its geology, whereas the Earth with all the attendant biota, is definitely not.