New Horizons shows Ultima Thule looks like a snowman, or maybe BB-8
The Kuiper Belt object is probably two rocks stuck together
The results are in: Ultima Thule, the distant Kuiper Belt object that got a close visit from the New Horizons spacecraft on New Year’s Day, looks like two balls stuck together.
“What you are seeing is the first contact binary ever explored by a spacecraft, two separate objects that are now joined together,” principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colo., said January 2 in a news conference held at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.
“It’s a snowman, if it’s anything at all,” Stern said. (Twitter was quick to supply another analogy: the rolling BB-8 droid from Star Wars.)
That shape is enough to lend credence to the idea that planetary bodies grow up by the slow clumping of small rocks. Ultima Thule, whose official name is 2014 MU69, is thought to be among the oldest and least-altered objects in the solar system, so knowing how it formed can reveal how planets formed in general (SN Online: 12/18/18).