Image above: the Korolev crater near the north pole of Mars. Source: ESA.
The European satellite Mars Express arrived in orbit around the red planet on Christmas Day 2003. Since then, we have been permanently enjoying beautiful images and interesting measurements. Even now, the satellite is still ‘making itself heard’ (seen, that is, actually). So I wanted to share these two pictures of the Korolev crater from December 2018 on this blog, because they are too beautiful not to show. Sergei Korolev, by the way, is the legendary space engineer who put the Soviet Union ahead of the USA in the early days of space exploration. The crater is full of ice in a so-called cold trap. The light from the low sun at the North Pole does not reach the 2 km deep bottom of the crater, which is why it is ice and ice cold there. The air descending into it cools immediately, suspended above the ice. This allows the water ice to remain in very low temperatures.
The pictures were compiled after 5 passes of the satellite (5 strips). The crater is 82 km wide and the layer of water ice is 1.8 km deep.
A few months before, this crater rim had also been photographed by the ESA Exomars satellite TGO, with the CASSIS camera. Make the comparison yourself.
