To find life on Mars, scientists may need to give up surface exploration and “go deep.”
Typically, Mars missions searching for signs of life target the planet’s surface, at sites where there are signs of ancient water (a reliable indicator of where life is found on Earth). But while no life has turned up yet on Mars’ surface, there may be an abundance of microbial Martians congregating underground, according to research presented Dec. 11 here at the annual meeting of the American Geophysical Union (AGU).
In recent decades, explorations underground on Earth have revealed the so-called deep biosphere — a subsurface environment teeming with microorganisms. And scientists suspect that a similarly biologically-rich zone may be thriving under Mars’ surface, too.
In fact, perhaps there was never an evolutionary push to inhabit the surface of Mars at all, Joseph Michalski, an associate professor with the Department of Earth Sciences at the University of Hong Kong, said at the presentation. The expectation that life evolved on the Martian surface may reflect a bias established by what we know about life on our home planet, Michalski said.