By looking at the geology of Mars’ northern plains, scientists are predicting that oceans on Mars may have formed through slow groundwater seepage through the surface crust. If this prediction is anywhere near accurate, the process involved would have formed oceans/lakes in an incredibly short amount of time–a couple of years–but also could’ve sustained them for millenia. Even though the planet might have been wet, the fact remains that it had a very thin atmosphere, meaning that if life existed, you would have had to look in places where the water was not exposed to extreme changes in temperature or where the water was the recipient of direct radiation. In essence, you’d have to had to find pockets where water was stable (in Mars’ case, this would be in the subsurface). This is where fossil seekers face a huge dilemma: how can we dig below a surface if our robotic rovers aren’t currently equipped with the tools/parts we need? According to the new study, however, it’s very likely that fossils formed in the subsurface along the northern plains (due to the history of ancient groundwater and sediment deposits): the sediments would then be deposited on the surface from the prehistoric seas and these the rover can actually reach. The huge sediment deposits along these plains are thought to be accurate because they strongly resemble the floor bottoms of many of our oceans here on Earth. Based on the geology of the rocks located in the basins/craters lining the northern plains, scientists have found evidence that groundwater has probably welling up to the surface for nearly two billion years. They have predicted that the source of this groundwater is an extensive underground aquifer located deep below the surface. To back up their theory that the oceans/lakes were sustained for millenia, scientists also project that, as long as the groundwater continued to seep between cracks in the surface, the waters would undergo period intervals of freezing and thawing, very similar to what the Martian ice caps undergo today. Due to the high-saline nature of these lakes/oceans, it’s predicted that organisms living beneath the surface would be able to survive upon encountering radiation- thus allowing them to adapt and make the transition to a new life. When dreaming of what Martian fossils will look like, however, many scientists tell us not to be surprised if the preserved remnants are very different from the ones we’ve found so far here on Earth. In other words, it won’t necessarily be bones that we might be digging up someday soon: it could be traces or chemical indicators or even microorganisms the likes of which we’ve never seen. Taking all of this into consideration, the thought that there really may have been life on Mars at some point in time and the idea that we might have the evidence to back it up is tantalizing to say the least. As our beloved producers of The Twilight Zone put it, “We are not alone”—and for once, it’s a refreshing thought.