An international team of planetary scientists led by Cote d’Azur Observatory staff working on the OSIRIS-REx mission analyzed the cracks of asteroid Bennu and discovered that its map changes very rapidly under the influence of the Sun. The study was published in the journal natural science.
Although asteroids are one of the oldest components of the solar system, they are very volatile as they collide constantly, causing changes in their shape and size. Apparently, their surfaces are subject to very rapid erosion by solar heat. Over time, cracked materials can even be launched into space.
Another clue to the change in temperature appeared in the cracks in the asteroid. The scientists measured the lengths and angles of these cracks and noticed that they were a clear sign of temperature fluctuations during the day. The cracks line up mainly in the northwest-southeast direction. If the cracks were due to landslides, they would be placed randomly.
Such changes make the asteroid’s topography look very young, but don’t be fooled: It actually has very old rocks on its surface, exposed by the destruction of the upper layers. As early as 2023, scientists will be able to collect a sample from Bennu’s surface when the OSIRIS-REx mission ends.