NASA’s Lucy Spacecraft Snaps First Look at Upcoming Asteroid Target

The Lucy spacecraft just got its first good look at the main belt asteroid Donaldjohanson as the NASA mission prepares to explore the Trojan asteroids as far out as Jupiter.

Donaldjohanson is not a Trojan asteroid, but is located in a convenient position for Lucy to swing by before continuing on to its main targets. Donaldjohanson—named for the anthropologist who discovered the fossilized hominid Lucy in 1974—is a small main belt asteroid at roughly 3 miles (4 kilometers) in diameter.

Newly released NASA images show the asteroid as a faint smudge of light in two views captured by Lucy’s LOng Range Reconnaissance Imager (or L’LORRI, for short).

The images (below) show Donaldjohanson as it appeared 45 million miles (70 million kilometers) from Lucy. But the spacecraft will close that distance by April 20, 2025, when it is slated to make a close flyby of Donaldjohanson. During the flyby, Lucy will pass within 596 miles (960 kilometers) of the asteroid.

Lucy launched in October 2021 and, very early in the mission, observed the asteroid Dinkinesh and its tiny moon. Late last year, the spacecraft slingshotted around Earth—its second gravity assist of our world—as it prepared to speed off to Donaldjohanson. The gravity assist increased Lucy’s speed with respect to the Sun by over 16,000 miles per hour (25,750 kilometers per hour).

Though Donaldjohanson is just a preamble to Lucy’s main event, the asteroid is compelling in its own right. Donaldjohanson is thought to be a piece of debris from a massive collision about 130 million years ago, a collision that created the Erigone family of asteroids, according to the Lucy mission site.

Lucy will continue to image Donaldjohanson over the next two months as part of the mission’s optical navigation program. Donaldjohanson will continue to appear as an unresolved faint smudge until the April 20 flyby.

The first Trojan asteroid on Lucy’s to-see list is Eurybates, which is much larger than Donaldjohanson—about 40 miles (64 kilometers) across. The Eurybates flyby will help researchers understand how the Trojan asteroids ended up mostly together in front of Jupiter in its orbit of the Sun, and why the Trojans have the compositions that they do. The Eurybates flyby will also let Lucy spot Queta, Eurybates’ puny satellite. The flyby will take place on August 12, 2027.

Lucy will perform flybys of a troop of Trojans in the coming years, with the final flyby (of Patroclus and Menoetius, the two asteroids featured in the top image) in 2033. But thereafter, Lucy will stay in a stable orbit and should continue flying through the Trojans for years to come.