According to study, it rained on ancient Mars
Actually, a study of the martian landscape attests that there has not only been rain, but also rivers on the red planet.
The rivers may have flown in the valleys from the highlands near the martian equator ( such as the Xanthe Terra highland region). Also, signs of fan-shaped river deltas have been observed inside ancient craters in which some valleys end.
Ernst Hauber, geologist at the DLR Institute of Planetary Research in Berlin – Adlershof, speaks about layered sediments existing at the openings of the valleys into craters: “ The shape of certain sediments is typical for deltas formed in standing water.”
Sediment is carried down the river until the place where the currents become too weak. Eventually, the flow almost stops when it empties into a larger body of water, such as a lake-filled crater. One such crater, 3-mile small and filled with sediment up to 164 feet, may be a proof of such a fan-shaped delta, into which the Nanedi river flows.
According to the number of craters which can roughly indicate the age of the planetary surface, the water may have flowed in the valleys sometime between 3.8 and 4 billion years ago.
Recent research presented at the European Planetary Science Congress in Münster, Germany, attests the role played by rain and snowmelt in the creation of the valleys.
