It seems to be a completely crazy idea to search for ice on Mercury - the first planet from the Sun. But a study of 30 years in length shows that water freezes in the crater floor, which is in eternal shadow. Now scientists think that there is even more ice than previously thought.
Large deposits are located near the north pole of the planet. But there are also small deposits around the North Pole, both inside the craters and between them, where the shadow lies.
The idea of the presence of ice on Mercury appeared in the 1990s, when ground-based radar telescopes recorded areas with a high level of reflection. The planetary axis is devoid of a remarkable inclination, therefore direct stellar rays do not fall on the poles. There is no atmosphere, so in the shaded areas there is a low temperature regime, which means there is an opportunity for the presence of ice.
Scientists have found new data on ice sheets in constantly shaded craters located near the north pole of Mercury. It is believed that there may be small precipitations between the craters, which replenishes ice reserves. The first evidence came with the probe MESSENGER, which entered the orbit of Mercury in 2011. The device recorded signals from the north pole corresponding to water ice. Calibration helped to find the highest levels of reflection, which corresponded to the position of three large craters.
The total area reaches 3400 km 2. But the researchers also decided to explore the area around the craters. The landscape did not differ in the same brightness, but still exceeded the level of other territories. We managed to find 4 positions with a diameter of 5 km. But these are only those that turned out to be resolved. It is believed that the reserves are much more.
It is still unclear how the ice in general turned out to be on Mercury. Most agree that the cause was comets and asteroids. Or hydrogen could come with the solar wind. New research will help to better understand exactly how water and other volatile substances have spread in the internal system.