December 13
Comet Wirtanen
Observed in 2018
In this image, the nucleus of comet 46P/Wirtanen is hidden in the center of a fuzzy glow from the comet's coma. The coma is a cloud of gas and dust that the comet has ejected as it is heated by the Sun during its passage through the inner solar system.
Image credit: NASA, ESA, Hubble Space Telescope