It rained on Mars – 3 billion years ago

PARIS – Mars was not only awash with water, it also once had rainfall, according to a French study.

The evidence comes from infra-red imaging, which probed under dust deposited over the millions of years and found dense networks of dry valleys, whose branching bear the hallmarks of having been carved out by rain. The research, published in the US journal Science, could prompt a rewrite of the Martian history books, for it suggests the planet had a longer “summer” than anyone thought.The conventional theory is that Mars had a balmy climate during its infancy, a period called the Noachian era, in which vast volumes of water flowed on its surface, cutting valleys and eroding the craters left by asteroids.Then, around 3,6 billion years ago the planet froze, entering the so-called Hesperian epoch, which lasted around half a billion years.Their analysis is based on data sent back the thermal Emission Imaging System (THEMIS), which has been scanning the planet since October 2001 aboard a NASA orbitor, Mars Odyssey.- Nampa-AFPThe research, published in the US journal Science, could prompt a rewrite of the Martian history books, for it suggests the planet had a longer “summer” than anyone thought.The conventional theory is that Mars had a balmy climate during its infancy, a period called the Noachian era, in which vast volumes of water flowed on its surface, cutting valleys and eroding the craters left by asteroids.Then, around 3,6 billion years ago the planet froze, entering the so-called Hesperian epoch, which lasted around half a billion years.Their analysis is based on data sent back the thermal Emission Imaging System (THEMIS), which has been scanning the planet since October 2001 aboard a NASA orbitor, Mars Odyssey.- Nampa-AFP