“Very early in Mars’ historical past, perhaps 4 billion years in the past, the planet was heat sufficient to help lakes and river networks,” Kite advised Ars. “There have been seas, and a few of these seas had been as huge because the Caspian Sea, perhaps larger. It was a moist place.” This moist interval, although, didn’t final lengthy—it was too brief to make the panorama deeply weathered and deeply eroded.
Kite’s crew used their mannequin to give attention to what occurred because the planet obtained colder, when the period of salts began. “Large areas of snowmelts created enormous salt flats, which ultimately constructed up over time, accumulating right into a thick sedimentary deposit Curiosity rover is presently exploring,” Kite mentioned. However the period of salts didn’t mark the tip of liquid water on the Martian floor.
Flickering habitability
The panorama turned arid, judging by Earth’s requirements, roughly 3.5 billion years in the past. “There have been lengthy intervals when the planet was totally dry,” Kite mentioned. Throughout these dry intervals, Mars was virtually as chilly as it’s at present. However every so often, small areas with liquid water appeared on the Martian floor like oases amidst an in any other case unwelcoming desert. It was a sterile planet with flickering, transient liveable spots with water coming from melted snow.
This somewhat bleak image of the Martian panorama’s evolution makes questions on our possibilities for locating traces of life in there tough.
“You are able to do a thought experiment the place you’re taking a cup of water from the Earth’s ocean and pour it into a type of transient lakes on Mars,” Kite mentioned. “Some microbes on this cup of water would do positive in such situations.” The larger query, he thinks, is whether or not life may originate (somewhat than simply survive) on historic Mars. And, maybe extra critically, whether or not hypothetical life that originated even earlier than the salts period, when the planet was heat and moist, may persist within the oases popping up within the Kite’s mannequin.
The reply, sadly, might be not.
