Clay-Bearing Sediments on Mars Indicate Life May Have Thrived on the Red Planet Billion Years Ago

Astronomers and scientists have been striving to find signs of life on Mars through sophisticated missions and extensive research. Now, a latest study has indicated that a region on the Red Planet might have been “repeatedly habitable” until relatively late in Martian History. What caused scientists to conclude so is the discovery of clay-bearing sediments within the Margaritifer Terra region of Mars. The region has some of the most extensively preserved landforms that were created by running water on its surface.

“The presence of clays indicates an environment favourable for life because clays form and remain stable under neutral pH conditions where water persists long-term that minimises evaporation to form other minerals like sulfates,” said Catherine Weitz, Planetary Science Institute's Senior Scientist and lead author of the paper published in Icarus.

For the study, the researchers analysed data from NASA's High Resolution Imaging Science Experiment (HiRISE), Context Camera (CTX), and Compact Reconnaissance Imaging Spectrometers for Mars (CRISM) onboard the Mars Reconnaissance Orbiter spacecraft.

According to Weitz, they scanned the orbital images and spotted clay-bearing sediments within the northern Ladon Valles, southern Ladon basin, and highlands around Ladon basin. She highlighted that the colourful light-toned layered sediments indicate low bedding dips and have clay in the region across 200 kilometres. This, the scientist said, suggested that a lake existed within the Ladon Valles and Ladon basin.

Weitz further underlined that factors such as the low-energy lake setting and the presence of clay would have offered favourable conditions for life to survive on the planet at that time. It was observed that the Ladon basin region once had water flowing on its surface. It began roughly 1.8 billion years ago and ended around 2.5 years ago.

The researchers concluded that the clay first got accumulated in the older highlands terrains in the Ladon basin. Later, water eroded the sediments containing the clay and formed the Ladon Valles channel. The clay then ended up getting deposited downstream in the lake in the Ladon basin and northern Ladon Valles region.

“Our results indicate that the clay sediments deposited by running water in Eberswalde were not unusual during this more recent time because we see many examples of similar young valleys that deposited clays in the region,” Weitz said.