For decades, scientists have been scanning Mars’ surface for signs of ancient life. But by digging a little bit deeper, they’ve come across historic habitable zones in unexpected places.

After expanding their search, a team of researchers found that the Red Planet’s ancient subsurface could have housed microbial life for hundreds of millions of years. By borrowing hydrogen electrons from water, microbes could’ve had enough energy to not only survive underground, but to thrive for miles be