NASA’s Lucy spacecraft is about to have its second close encounter with an asteroid

A NASA spacecraft will make a close approach to an asteroid in the main belt on Sunday afternoon, in the second of several asteroid flybys planned for its 12-year mission to study remnants of the early solar system. The Lucy spacecraft will be 596 miles (960 km) from asteroid Donaldjohanson — named after the paleoanthropologist who discovered the “Lucy” hominin fossil — at the closest point of its pass, which will occur at 1:51PM ET, according to NASA. Lucy will use three instruments to capture detailed observations as the object gets closer, rotating with the asteroid over a few hours to get the full picture. It will stop tracking just before the asteroid is nearest, when it’ll have to shield its instruments due to the position of the sun to prevent damaging them.

The spacecraft previously visited a small asteroid called Dinkinesh in 2023, and its observations revealed that the asteroid is orbited by what’s known as a contact binary, or a peanut-shaped double moon “made of two smaller objects touching each other,” NASA explained at the time. After Donaldjohanson, Lucy will move on to its main targets, a handful of “Trojan” asteroids orbiting the sun in the same path as Jupiter. It’s expected to reach the first of those objects in 2027.

“Every asteroid has a different story to tell, and these stories weave together to paint the history of our solar system,” Tom Statler, Lucy mission program scientist, said in a press release. “The fact that each new asteroid we visit knocks our socks off means we’re only beginning to understand the depth and richness of that history. Telescopic observations are hinting that Donaldjohanson is going to have an interesting story, and I’m fully expecting to be surprised — again.”