Scott Sheppard and Chad Trujillo Discover One of the Most Distant Comets to Show Activity
Scott Sheppard, along with Chad Trujillo of the Gemini Observatory in Hilo, Hawaii, discovered their first comet during observations at the Cerro Tololo Interamerican Observatory (CTIO) 4 meter telescope while looking for objects in the far outer reaches of the Solar System.
The comet, named Sheppard-Trujillo after its discoverers, is one of the most distant comets ever discovered to show activity. Sheppard-Trujillo is currently about 13 AU from the Sun, making it more distant from Earth than Saturn. At this distance, water ice is too cold to efficiently sublimate off the surface of an object and thus the activity is likely caused by carbon monoxide or carbon dioxide sublimation, which is different than most comets that have their activity dominated by water ice sublimation.
Sheppard-Trujillo also has an interesting orbit that will bring it in the vicinity of Jupiter at about 5 AU in 2021. The low inclination of Sheppard-Trujillo suggests it likely came from the Kuiper Belt region just beyond Neptune. The comet will likely gravitationally interact with Jupiter over the next few million years and eventually be ejected from the Solar System or collide with a planet or the Sun.