Signs in Martian soil point to habitable conditions for life over a long period of time

Is there life on Mars? Has it ever been? This is one of the biggest questions we have about our planetary neighbor; now research points to a specific part of the red planet that could have been able to house life several times over billions of years.

Through a thorough study of images taken by the Mars Reconnaissance Orbiter, planetary scientists have identified clay-bearing sediments over northern Ladon Valles, the southern Ladon Basin and the southwestern highlands around the Ladon Basin – all parts of the extensive Margaritifer Terra crater.

Clay indicates the long-term presence of water, as it is formed under neutral pH conditions with minimal water evaporation. The team believes the water flowed here from around 3.8 billion years ago to around 2.5 billion years ago, a large part of Mars’ history.

“In addition, there are colorful light-toned layered sediments that show relatively low bed dives and contain clay over 200 kilometers [124 miles] in the distance is evidence that a lake was most likely present in the Ladon Basin and northern Ladon Valles, “said Catherine Weitz, a senior researcher at the Planetary Science Institute in Arizona.

“The low energy setting and the presence of clay support an environment that would have been beneficial to life at that time.”

Although there is not exactly evidence of life – we have to dig on Mars for fossils to really confirm it – it suggests conditions that may well have supported life. This is the latest research to interpret the conditions on Mars from what we can see from the surface and the sediments.

Scientists believe that clay was originally formed around the higher ground above the Ladon Basin, before being eroded by water channels and transported downstream into a lake in the Ladon Basin and northern Ladon Valles.

According to the team, the last water flow would have been along the southwestern Ladon Basin. The deposits here correspond to another part of Mars, the Eberswalde Delta, just south of the region covered by this study.

“Our results indicate that the clay sediments deposited by running water in the Eberswalde were not uncommon in recent times because we see many examples of similar young valleys depositing clay in the region,” says Weitz.

We know that there is ice on Mars, but the search for liquid water continues. This latest study supports the idea that running water was once an extensive part of the Martian landscape – and it may have brought life to it.

How transient or otherwise the presence of water has been on Mars is crucial to determining whether life could have been supported at some point. The distribution of clays and other rocks discovered by the researchers is consistent with water sticking around.

In addition, clays are sources of nutrients and stabilizers for the environment around them. Put water, nutrients and stable conditions together, and the chances of organisms surviving increase considerably.

“Habitable conditions may have occurred repeatedly in the region, at least periodically, until relatively late in Mars history,” the researchers write in their published article.

The research is published in Ikaros.