Lucy Captures Its First Images of Main-Belt Asteroid Donaldjohanson

NASA’s Lucy spacecraft will fly by the small asteroid Donaldjohanson on April 20, 2025.

By blinking between images captured by NASA’s Lucy spacecraft on February 20 and 22, 2025, this animation shows the perceived motion of Donaldjohanson relative to the background stars as the spacecraft rapidly approaches the asteroid. Image credit: NASA / Goddard / SwRI / Johns Hopkins APL.

Donaldjohanson is a carbonaceous asteroid approximately 4 km (2.5 miles) in diameter.

First discovered on March 2, 1981 by the American astronomer Schelte Bus at the Siding Spring Observatory, it orbits within the inner regions of the main asteroid belt.

NASA’s Lucy spacecraft will pass within 960 km (596 miles) of Donaldjohanson on April 20.

“This second asteroid encounter for Lucy will serve as a dress-rehearsal for the spacecraft’s main targets, the never-before-explored Jupiter Trojan asteroids,” members of the Lucy team said in a statement.

“The spacecraft already successfully observed the main-belt asteroid Dinkinesh and its moon, Selam, in November 2023.”

These new images captured by the Lucy LOng Range Reconnaissance Imager (L’LORRI) instrument.

This illustration shows NASA’s Lucy spacecraft passing one of the Trojan asteroids near Jupiter. Image credit: Southwest Research Institute.

“From a distance of 70 million km (45 million miles), Donaldjohanson is still dim, though it stands out clearly in this field of relatively faint stars in the constellation of Sextans,” the researchers said.

“Celestial north is to the right of the frame, and the 0.11-degree field of view would correspond to 85,500 miles (140,000 km) at the distance of the asteroid.”

“In the first of the two images, another dim asteroid can be seen photobombing in the lower right quadrant of the image.”

“However, just as the headlights of an approaching car often appear relatively stationary, Donaldjohanson’s apparent motion between these two images is much smaller than that of this interloper, which has moved out of the field of view in the second image.”

According to the scientists, Donaldjohanson is named for the anthropologist Donald Johanson, who discovered ‘Lucy’ — a 3.18-million-year-old specimen of Australopithecus afarensis. The Lucy mission is named for the fossil.

“Lucy will continue to image Donaldjohanson over the next two months as part of its optical navigation program, which uses the asteroid’s apparent position against the star background to ensure an accurate flyby,” they said.