The Surface of Mars Shaped by Rainfall, not Volcanoes

The Surface of Mars (Image credit to NASA)

Research says the fall of rain helped to carve the valley network on the surface of Mars. Consequently, this latest finding also suggests that the Martian atmosphere at the time was considerably colder than first thought, implying to the vital source of life (water).

For decades, scientists have operated under the assumption that the intricate lithosphere of the Red Planet was shaped by the ancient activity of Tharsis plateau, home to the largest volcano in our Solar System – however, new research says the deep and winding valleys on Mars’ surface were actually created by rain and snowfall in the planet’s youth.

Tharsis was formed around 3.7 billion years ago in a period of Martian history known as the Noachian Era and it has long been thought as the cause of these lithosphere alterations, with its massive tonnes causing the mantle to tear and shift as it began to form. Since these valleys are oriented in the same direction, parallel to the equator of the planet, the Tharsis theory has remained the most plausible scientific argument.

A team lead by Sylvain BOuley, a planetary scientist at the University of Paris-Sud, France, theorises that these valleys are instead the networked remains of a complex system of rivers that ran around the surface in a thick, criss-crossed band. More so, these valleys were created during the same period as Tharsis’ formation, rather than as a direct by-product of its rise.

The researchers ran 3D simulations that showed the river network grew during the theorised heavy rainfall of the Noachian Period as the Tharsis bulge continued to rise, with the band shifting over the Martian equator as the period drew a close.