The Mars Express spacecraft of the European Space Agency (ESA) was launched into space on June 2, 2003 and arrived on Mars six months later. The ship lit its main engine and entered orbit around the planet on December 25, so this month marks 15 years of its insertion into orbit and the beginning of its scientific program.
A spectacular image of the Korolev crater taken by the ship is perfect for celebrating the anniversary. Captured by the Mars Express High Resolution Stereo Camera (HRSC), it comprises five "fringes" captured in different orbits and combined to form a single image.
Perspective view of the Korolev crater. (Photo: ESA / DLR / FU Berlin, CC BY-SA 3.0 IGO)
The Korolev crater is 82 kilometers in diameter and is located in the lowlands of northern Mars, south of a vast dune-bound land that circles part of the planet's north pole and is known as Olympia Undae. It is a particularly well-preserved and not only snow-covered crater, but throughout the year features a 1.8-kilometer-thick water ice in the center.
This continual presence of ice is due to a phenomenon aptly called a "cold trap," because that is exactly what it does. The crater is deep, with the bottom about two kilometers below the vertical edge.
The lower parts of Korolev, which are those containing ice, "trap" the cold: air that moves over the ice tank cools and descends, forming a layer of cold air just above the ice.
This layer of cold air acts as a shield and helps the ice to remain stable, preventing it from becoming hot and disappearing. Because air is a bad conductor of heat, this effect is exacerbated and allows Korolev to retain its ice.
The crater is named after the engineer and chief designer of rockets Sergei Korolyov (Sergei Korolev), considered the father of Soviet space technology.
Korolyov participated in several famous missions, like the program Sputnik, that in 1957 and the following years put in orbit around the Earth the first artificial satellites; the Vokshod and Vostok manned space exploration programs, which in 1961 brought the first human – Yuri Gagarin – into space; as well as the first interplanetary missions to the Moon, Mars and Venus. He has also worked on some of the forerunner rockets of successful Soyuz launchers, Russian space program chiefs and officials for manned and robotic flights.
This region of Mars has also been of interest to other missions, including ESA's ExoMars program, whose purpose is to determine if there ever was a life on the planet. (Source: ESA)