Well, not exactly – more like terrestrial microbes living in harsh environments like those Mars likely had some time back.
Minerals on Mars studied by the NASA rovers suggest water once flowed on the planet’s surface, but was very salty and acidic, raising doubts about whether it could have supported life.
But in 2007, Melanie Mormile of Missouri University of Science and Technology in Rolla and colleagues cultured a bacterium from water sampled from one of several salty, acidic lakes in Western Australia.
The lakes are very shallow and periodically fill with rainwater before partially evaporating, which concentrates the salts within them. They may be the closest equivalents on Earth of the shallow pools thought to have once dotted Mars.
Which leaves me to wonder if there aren’t pockets of salty, acidic water remaining underground on Mars, warmed by residual internal heat from the planet, where such microbes might have migrated from the surface as conditions there grew (even) less hospitable.