Another of the Lucy Mission’s Asteroids has a Moon

We don't know a lot about the asteroids. It is difficult to keep track of all the missions that have been sent to the asteroid belt. Even though Lucy is supposed to help with that, it doesn't know what it is doing. The mission designers thought there were only a few things to explore. The mission will visit nine asteroids instead of seven because of the discovery of another asteroid in the same area.

Nine is two more than seven and that is the number of asteroids that the spaceship will be visiting. Nine months before the mission launched, a team discovered a companion asteroid in Eurybates.

The team responsible for Lucy was still trying to collect as much data as possible despite the fact that it was mostly fixed. Polymede was one of the asteroids Lucy planned to visit.

It was using a light saber. There could be more information about this object that is so small and distant. It's like trying to see a quarter on the streets of Los Angeles from New York.

On March 27 of this year, the Lucy team asked a group of astronomy groups to spread out across the path of the occultation. Two of the observations held a special surprise.

They saw something in front of the star that wasn't Polymede, but was somewhere else. The head of Lucy's occultation team said it had to be a satellite. Polymede is only 27 km long on its longest side, but the object itself is 5 km long.

The team won't be able to name the satellite until they can determine its orbital pattern. The satellite is too small, dim, and close to Polymede to be seen by near- Earth telescopes. One of the possibilities is that Lucy arrives in the system around the year 2077.

A star occultation has happened before. In October last year, we reported on an occultation of Eurybates, one of Lucy's targets. It is not clear if the same satellite was caught by that occultation. Lucy's twelve-year mission may need to change the mission tag line from "Seven asteroids, one spacecraft" to "Two bonus asteroids." There are a lot of changes before Lucy visits Patroclus.

You can learn more.

Lucy and her team discover the moon around a asteroid.

Astronomers lined up under an asteroid's shadow to measure its size.

Lucy occultation events are held here.

Lucy's solar array is fixed. Most of the time.