101 Must-See Cosmic Objects: M109

The third-largest constellation in the sky, Ursa Major, contains seven Messier objects. Five are galaxies. The least observed of these — based on the number of books and articles featuring it — is M109, also known as NGC 3992. Messier’s original catalog topped out at 103, but today, astronomers recognize […]

A pimple on Jupiter

During the thirty-sixth close approach of the gas giant planet Jupiter by NASA’s Juno spacecraft, it snapped a raw image of tumultuous clouds in the South Temperate Belt.