Colorado spacecraft takes unscheduled flyby of mystery asteroid

A Colorado-built spacecraft named Lucy made a brief unscheduled flyby of a small asteroid Wednesday morning while on its way to study a different asteroid belt even farther away from Earth.

"We expected it to just be a boring old rock in the inner part of the solar system," said Hal Levison, a planetary scientist with the Southwest Research Institute in Boulder. "But there's definitely a mystery going on here, it's not behaving like anything we've ever seen before."

He's talking about an asteroid known as Dinkinesh, or what his team has nicknamed "Dinky" because of its very small relative stature. It's located in the main asteroid belt between Mars and Jupiter, and it was not originally a scheduled stop for Lucy.

Levison is also the principal investigator for NASA's Lucy mission. He said Dinky was not on the original plan, but scientists added a flyby once they realized it was going to be in the direct path on its way to deeper space.

That way they could take the opportunity to test the sensors and practice for Lucy's scheduled encounters, which are eight Trojan asteroids starting in March 2027. The flyby became even more interesting when scientists noticed a strange anomaly in light measurements.

"When you look at how the light is varying when you look at it from Earth and when you look at it from the spacecraft, they're not behaving in a consistent way," he said. "It could be that there's a satellite, or maybe it's a binary, or maybe it's just got a very weird shape."

He said the team could find out what's going on with Dinkinesh as soon as Thursday morning. Lucy was also able take about 57 images of the asteroid, which also could get release to the public soon.