Nobody knows for sure whether or not life had ever taken root on Mars. The dry, dusty planet doesn’t seem like a particularly hospitable place these days but things were likely a whole lot different several billions of years ago. Now, a new study suggests that if we’re going to hunt for Martian fossils there’s one particularly promising place we should be searching.

The study, which was led by a researcher from the University of Edinburgh, was published in the Journal of Geophysical Research. It focuses on some very specific places on the red planet where fossils are likely to exist, namely inside rocks near long-dead lakes, using knowledge from gained from fossil hunting here on Earth to give Mars researchers their best shot at finding evidence of Martian life.

“The Martian surface is cold, dry, exposed to biologically harmful radiation and apparently barren today,” the research team — which also includes members of NASA’s Jet Propulsion Laboratory as well as scientists from Brown, MIT, and Yale, amongst others — explains. “Nevertheless, there is clear geological evidence for warmer, wetter intervals in the past that could have supported life at or near the surface. This evidence has motivated National Aeronautics and Space Administration and European Space Agency to prioritize the search for any remains or traces of organisms from early Mars in forthcoming missions.”

With that in mind, the scientists suggest that the mud and clay that rested on the shores of ancient Martian lakes is likely a good place to find fossils. As the moist mud hardened into rock over millions of years, it’s likely to have captured evidence of life if there was any roaming on the surface at that point in time. The silica and iron-rich makeup of the rocks also facilitates the preservation of fossil evidence, according to the researchers.

“There are many interesting rock and mineral outcrops on Mars where we would like to search for fossils,” Dr Sean McMahon of the University of Edinburgh notes. “But since we can’t send rovers to all of them we have tried to prioritise the most promising deposits based on the best available information.”

Let’s hope they find something interesting!