Scientists have discovered fascinating details about a small asteroid named Dinkinesh, which was visited by NASA’s Lucy spacecraft last November. The asteroid has a moonlet named Selam, consisting of two bodies that merged together.
Dinkinesh and Selam are the smallest asteroids from the main asteroid belt between Mars and Jupiter to be observed up close by a spacecraft. Lucy’s observations revealed ridges, trough structures, and other features on Dinkinesh, indicating a complex history for the asteroid and its moonlet.
NASA launched Lucy in 2021 on a mission to study asteroids, including Jupiter’s Trojan asteroids. During its journey, Lucy passed by Dinkinesh and Selam at the inner edge of the main asteroid belt.
Dinkinesh has a diameter of about 720 meters, while Selam consists of two lobes, each around 230-210 meters wide. Selam orbits Dinkinesh every 53 hours at a distance of 3.1 km.
It is believed that a large piece of rock broke off from Dinkinesh in the past, creating a trough on its surface and forming Selam. Selam is classified as a contact-binary moonlet, where two objects gently collided and merged.
Lucy will continue its mission to study asteroids, with the next stop being the asteroid Donaldjohanson in 2025. The visit to Dinkinesh was a valuable test for the Lucy mission, demonstrating the spacecraft’s capabilities and performance.
