The new study showed that the water on Mars did not dry up immediately, and the planet fluctuated between dry and wet periods. After some time, the planet became completely dry.
Previous researchers have suggested that Mars was once wet enough to cover its entire surface with an ocean containing about half the water content of the Atlantic Ocean. However, according to NASA, the Red Planet is now unusually dry. It contains a thousand times less water than the Atacama Desert in Chile, the driest place on Earth.
To figure out exactly how Mars dried up, scientists analyzed data from NASA’s Curiosity rover. Now the device is exploring the base of Mount Sharp – a giant mound with a height of approximately 5.5 km. The device examined the composition of this mountain to get an idea of what kind of environment formed this part of Mars.
Scientists have focused on sedimentary layers about 850 m thick. The base of Mount Sharp consists of clays about 300 m thick, which have formed in lakes. Above this, the researchers found wide, erosion-hazardous layers about 150 m thick, which probably appeared due to the wind. Then scientists found alternating light and dark rocks that usually appear in rivers.
“We are seeing constant changes in climate recorded in the sedimentary structure of the mound,” scientists from NASA noted.