The Lucy spacecraft is headed for the Trojan asteroids – big chunks of rock and metal that share an orbit with Jupiter. But it’s checking out some other sights along the way. This weekend, for example, it’ll pass just a few hundred miles from a body in the asteroid belt, between the orbits of Jupiter and Mars.

Lucy is named for the fossilized remains of a human ancestor. The name was selected because the Trojans are fossil remnants of the early solar system. The mission’s current target is 52246 Donaldjohanson – named for the scientist who discovered Lucy half a century ago. The name was chosen after the asteroid was picked as a target for the spacecraft.

The asteroid is pretty small – only about two and a half miles in diameter. And Lucy will zip by at 30,000 miles per hour. So it won’t have long to study the target. But its pictures and other observations ought to tell us about the asteroid’s mass, shape, and composition.

Donaldjohanson is one of about 2,000 asteroids that are related – they were splintered off a parent body by a big collision. So Lucy’s encounter should tell us not only about Donaldjohanson’s history, but the history of its entire family.

This is Lucy’s second encounter with a member of the asteroid belt. After today, the craft isn’t scheduled to check out any other sights along the way. It’ll reach the Trojans in August of 2027.

Script by Damond Benningfield