NASA specialists have published detailed images of the asteroid Donaldjohanson, obtained by the Lucy probe. April 20, it made its close passage.
The Lucy mission was launched in 2021. Its main task is to study Jupiter’s Trojan asteroids. But the trajectory of the vehicle was built in such a way that the vehicle visited several passing objects on the way to its goal. The first was the small asteroid Dinkinesh, whose flyby took place on November 1, 2023. It turned out to have a tiny companion, which was named Selam.
The next companion object was the Main Belt asteroid Donaldjohanson. On April 20, Lucy flew at a distance of 960 km from it. Preliminary analysis of the first images showed that the asteroid is larger than expected: its length is 8 km, and the width at its widest point — 3.5 km. The asteroid is rotating very slowly. Its apparent rotation in the animation published by NASA is due to the motion of the spacecraft flying past Donaldjohanson.
According to experts, the asteroid has a strikingly complex geology. The Lucy images confirmed previous speculation that Donaldjohanson was a contact object formed by a low-speed collision between two small bodies. It is estimated to have occurred about 150 million years ago. Scientists were surprised by the strange shape of the narrow neck connecting the two parts of the asteroid. It looks like two ice cream cones nested inside each other.
This is just an initial set of images that do not show Donaldjohanson in its entirety because its size exceeds the camera’s field of view. It will take up to a week to transmit the rest of the data and images from the spacecraft. They will give a better idea of the overall shape of the asteroid. As scientists study its structure in more detail, they will be able to learn more about the building blocks and collision processes that formed the planets in the solar system.
The visit to Donaldjohanson was a dress rehearsal before the mission’s main science program began. Lucy will start in August 2027 when it will fly by the Trojan asteroid Eurybates, located at the L4 Lagrangian point of the Sun-Jupiter system.
According to NASA
