April 18, 2024
Comets are frozen remnants leftover from the formation of our solar system about 4.6 billion years ago. They are comprised of mostly ice and some rock and dust. The current number of known comets is around 3,910.
The nucleus of Comet 67P/Churyumov-Gerasimenko imaged by the Rosetta spacecraft on Jan 31, 2015. Image credit: ESA/Rosetta/NAVCAM CC-BY-SA IGO 3.0