Of course the fact that the abundance of isotopes found in what little is left of the Martian atmosphere could have only come from a large nuclear explosion...
Boom... mic drop and silence.
• Mars was apparently Earthlike for most of
its history with an ocean and persistent
greenhouse like on Venus
• Then, ~0.5Billion years ago Mars suffered a
Chixulube-size impact formed the Lyot
Impact Basin and apparently collapsed
Mars climate and dried up its oceans
• Then, after some indeterminate period
Mars suffered a bizarre nuclear disaster
http://spsr.utsi.edu/articles/Eviden...inMarsPast.pdf