Category

Astronomical objects discovered in 1789

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Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. It is about in diameter, about a tenth of that of Saturn's largest moon, Titan. It is covered by clean, freshly deposited snow hundreds of meters thick, making it one of the most reflective bodies of the Solar System. Consequently, its surface temperature at noon reaches only , far colder than a light-absorbing body would be. Despite its small size, Enceladus has a wide variety of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrain.

Mimas is the seventh-largest natural satellite of Saturn. With a mean diameter of , Mimas is the smallest astronomical body known to be roughly rounded in shape due to its own gravity. Mimas's low density, 1.15 g/cm3, indicates that it is composed mostly of water ice with only a small amount of rock, and study of Mimas's motion suggests that it may have a liquid ocean beneath its surface ice. The surface of Mimas is heavily cratered and shows little signs of recent geological activity. A notable feature of Mimas's surface is Herschel, one of the largest craters relative to the size of the

spiral galaxy in the constellation Ursa Major

starburst galaxy in the constellation Ursa Major

galaxy in the constellation of Hydra

interacting galaxy

galaxy in the constellation Leo

open cluster in Cepheus

interacting galaxy

galaxy in constellation draco

galaxy in the constellation Ursa Major