The region of Mars known as Ladon Valles could have been habitable repeatedly throughout its past thanks to the discovery of a lake that existed for billions of years. A recent article by Catherine Weitz of the Planetary Science Institute makes this point.

Life on Mars would be favorable

Landforms created by running water on Mars' surface are found in the Margaritifer Terra region, where clayey sediments have been found.

Clays indicate that the environment is favorable for life since clays form and remain stable in neutral pH environments, where water persists for a long time, minimizing evaporation to form other minerals such as sulfates'

A red planet's ancient lake

This article published in Icarus reveals that 'the Ladon Basin region within Margaritifer Terra records a long history of people living in the region' 

The history of water flow on Mars began roughly 3 billion years ago and continued until 2.5 billion years ago, which is considered relatively recent.

Lakes with low energy and clays create an environment that would have been conducive to life at that time. Initial clays formed in older mountainous terrain around the Ladon Basin, and later water eroded them to form the Ladon Valleys later sediment was deposited downstream in a lake within the basin and in the north of the region.

On Mars, how were traces of life found

Data from NASA's High-Resolution Imaging Science Experiment (HiRISE), Context Camera (CTX), and Compact Reconnaissance Imaging Spectrometers to Mars (CRISM) aboard the Mars Reconnaissance Orbiter spacecraft were used in the study.

Weitz said that orbital images allowed him to discover clay-bearing sediments in northern Ladon Valleys, the southern Ladon Basin, and the southwest highlands around the Ladon Basin.

Additionally, light-toned layered sediments containing clays showing relatively shallow slopes across a 200-kilometer distance indicate that a lake existed. Does Mars have a life? A lake of 1.3 billion years may indicate yes. Photo courtesy of Planetary Science Institute

A recent and youngest flow of water is found in the southwest Ladon Basin, where clays were deposited within basins and valleys that are similar in age, but smaller in scale compared to that of the Eberswalde delta located south of the study region.

According to our results, the clay sediments deposited by the Water stream at Eberswalde were not uncommon during that time period, as we see many examples of young valleys deposited clays at Eberswalde. MarsWeitz explained.