This comet originated in the Oort Cloud, a sphere of icy bodies far beyond the orbit of Pluto that contains the most remote and ancient objects in our solar system. The Oort Cloud envelops the entire solar system, extending from about 2,000 to 100,000 astronomical units (AU) from the Sun, where 1 AU is the Earth-Sun distance.
As the Sun and planets coalesced from the protoplanetary disk about 4.6-billion years ago, these comets originated in the region around Jupiter and Saturn, but when they got too close to the gas giants they were ejected to the solar system’s outer realms. Largely unchanged over billions of years, these rocky snowballs hold valuable clues to the origin and evolution of our solar system.
Comets in the Oort Cloud spend most of their time in distant, highly elliptical orbits, but if perturbed by gravitational interactions with passing stars or galactic tides can be thrown violently inward toward the Sun. The Sun’s heat causes ices in the comet’s solid nucleus to vaporize and form a glowing coma, releasing reflective dust and gases that can create a spectacular tail.
