Planetesimal

Debris disks detected in HST archival images of young stars, HD 141943 and HD 191089, using improved imaging processes (24 April 2014).[1]
486958 Arrokoth, the first pristine planetesimal visited by a spacecraft.

Planetesimals (/ˌplænɪˈtɛsɪməlz/) are solid objects thought to exist in protoplanetary disks and debris disks. Believed to have formed in the Solar System about 4.6 billion years ago, they aid study of its formation.

  1. ^ Harrington, J.D.; Villard, Ray (24 April 2014). "RELEASE 14-114 Astronomical Forensics Uncover Planetary Disks in NASA's Hubble Archive". NASA. Archived from the original on 2014-04-25. Retrieved 2014-04-25.