[Telepathic Intruder]

Rocks.

The atmosphere of Mars escaped into space less than a billion years after it formed, due to the solidification of its core and failure of its magnetic field. That's enough time for microbial life to form perhaps, but not higher forms.

[jmacusa]

You're 100% correct. It's the ‘’toe bone connected to the ankle bone connected to the shin bone’’ sort of sequence, as it were. A molten iron core produces a magnetic field. The magnetic field holds the atmosphere in place. As the inner core begins to cool down, the magnetic field begins to weaken and the atmosphere begins to dissipate. If there were ever life on Mars it almost certainly never developed beyond the microbial. The notion that some advanced, high tech civilization existed on Mars and then was some how zapped into nothing is science fiction and fantasy. In order for me to believe otherwise would require extraordinary proof of such a claim and to date nothing remotely approaching such fantastic claims has ever been found on The Red Planet.