New Horizon’s flyby of Arrokoth, a planetesimal in the Kuiper Belt, reveals a pristine object untouched since the solar system’s origin. Its shape and geology show that planetesimals form more gently than previously thought.
When NASA's New Horizons flew by a distant Kuiper Belt Object on New Year's Day, they nicknamed it "Ultima Thule." Now, the object has received an official moniker: Arrokoth.
This week in astronomy news, see two stunning images — one from the edge of the solar system, the newest image of Ultima Thule, and the other from the depths of the Coma Cluster of galaxies.
Alan Stern, principal investigator of NASA's New Horizons mission, gives a detailed preview of what the spacecraft will be doing in the days up to, during, and after the impending flyby of the Kuiper Belt Object 2014 MU69.