At the end of September, NASA announced the discovery of occasional streaks of flowing salty water on the slopes of mountainsides, canyons and craters on the southern hemisphere of Mars. A week later, and the Curiosity rover has been conducting further geological research at the lower part of Mount Sharp (Aeolis Mons), located on the vast Gale Crater, whose layer of sediments at the base of the mountain now suggest the crater once held a lake somewhere between 3.8 and 3.3 billion years ago.
This would indicate that the mountains surrounding the Gale Crater would once have been ice capped, and that water subsequently flowed down their steep slopes carrying sediment towards the crater’s center. In this way, the conspicuous presence of Mount Sharp on the central part of the Gale Crater is explained by repeated layers of sediment being deposited on the crater floor, before subsequently being shaped by Martian winds into the central standing feature it is today. As Sharon Wilson, a Smithsonian geologist involved in the Mars science study, explains:
“The sedimentary layers that make up the lower part of Mount Sharp were deposited in a lake environment. The material was transported from the crater interior by rivers on ancient Mars.”
In order for flowing water to have been a surface feature of Mars, the planet must once have had a warmer and wetter climate, offering a tantalizing possibility of life once having existed on the Red Planet. Needless to say, NASA’s Curiosity Mars, which touched down on the Bradbury Landing site back in 2012, will carefully be looking for signs of any extraterrestrial microbial life, whether living or preserved. As University of Utah geologist, Marjorie Chan explains:
“Although there is not yet definitive evidence for extraterrestrial life, the geologic results show that there were the key ingredients of water and places where water could have been accessible for microbial life to originate and evolve.”
Alfred McEwen, principal investigator of the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter, seems equally as confident mankind may be on the brink of discovering the first signs of life outside of our own earth. That likelihood is only set to increase further next year, after NASA launches a mission whose prime goals is to explore the planet’s interior, and discover whether the planet’s core is liquid or solid. As he explains:
“I think the possibility of life in the interior of Mars is rather high. It’s very likely, I think, that there is life in the crust of Mars – microbes. Maybe there’s something we can find close to the surface.”