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Sep 5, 2021
Asteroid Mathilde (253 Mathilde) became the third asteroid (after Gaspra and Ida), which was studied using spacecraft. In 1997, the American automatic interplanetary station NEAR Shoemaker, heading for the asteroid Eros, took several hundred images of the asteroid Matilda from a flyby trajectory from a distance of 1200 km.
Asteroid Matilda. A snapshot of the NEAR Shoemaker, 1997
The asteroid was discovered by the Austrian astronomer Johann Palisa in 1884 in Vienna. The name was invented by the French astronomer F. Leboeuf, who was the first to calculate the orbit of the asteroid.
Matilda belongs to the class C (high carbon) asteroids, so its surface is very dark, like asphalt. The density measured by NEAR Shoemaker instruments is 1300 kg / m³ - half that of conventional carbonaceous chondrite. This suggests that the asteroid may be composed of a pile of rock debris with many voids. More than 20 craters have been discovered on the asteroid, some of which are large.
One of the large craters of Matilda. Image of NEAR Shoemaker spacecraft, 1997
The largest of the craters has a diameter of 33 km and a depth of 6 km. The overall dimensions of the asteroid were determined: 66 × 48 × 46 km. Matilda's orbit lies entirely between the orbits of Mars and Jupiter and does not cross the orbits of the planets. One of the brightest anomalies of Matilda is the period of its rotation around its axis, which is 17 Earth days, while the periods of rotation of most asteroids are from 2 to 24 hours. Due to such a low rotation speed, only 60% of its surface was photographed.
Initially, scientists put forward the assumption that Matilda has a massive satellite, which by its tidal forces slows down the rotation of the asteroid, but the satellite was not found. Perhaps the slow speed of rotation could be caused by a collision with another asteroid moving in the direction opposite to the rotation of Matilda.
Related links:
ROSCOSMOS Press Release: https://www.roscosmos.ru/32430/
Moscow Planetarium: https://www.roscosmos.ru/tag/moskovskiy-planetariy/
Asteroid: https://www.roscosmos.ru/tag/asteroid/
Images, Text, Credits: ROSCOSMOS/Moscow Planetarium/Orbiter.ch Aerospace/Roland Berga.
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