a large rock in the middle of the night

Trans-Neptunian Object Caption This is an artist's concept of a craggy piece of solar system debris that belongs to a class of bodies called trans-Neptunian objects (TNOs). Credits Artwork: NASA, ESA, and G. Bacon (STScI); Science: NASA, ESA, and C. Fuentes (Harvard-Smithsonian Center for Astrophysics)