The Curiosity study of Gale Crater on Mars convinced scientists that the place was once filled with water. However, the question automatically arose – was it flowing, liquid water, or in the conditions of ancient Mars it could exist only in the form of ice and snow? The answer was unexpectedly found on Earth, in the land of ice and geysers – Iceland.
The Curiosity rover cannot rise from Gale crater high into the mountains, move along the channels of ancient rivers, so you have to study what is below – bottom sediments and sedimentary rocks. At first, they baffled scientists, since the erosion of rock fragments is barely expressed, and the sediments are full of fine fractions and minerals that the water should have washed long ago. However, this did not happen, which suggested that if there were rivers on Mars, it was only a small part of the year. Everything points to low planetary temperatures, on the verge of freezing water.
Researchers from Rice University began looking for similar places on Earth, for which they visited Antarctica, Hawaii and Iceland. It was in Iceland, where there are many basalt rocks and the average annual temperature does not exceed 3 ℃, that they discovered slow streams, the channels of which are very similar to the surface of Gale Crater. Based on these data, it was concluded that 3 billion years ago, Mars was a world of ice that fluctuated between the Antarctic cold and the Icelandic thaw.