MAGELLANIC CLOUD

either of two satellite galaxies of the Milky Way Galaxy, the vast star system of which the Earth is a minor component. These companion galaxies were named for the Portuguese navigator Ferdinand Magellan, whose crew discovered them during the first voyage around the world. The Magellanic Clouds are irregular galaxies that share a gaseous envelope and lie about 22 apart in the sky near the south celestial pole. One of them, the Large Magellanic Cloud (LMC), is a luminous patch about 5 in diameter, and the other, the Small Magellanic Cloud (SMC), measures less than 2 across. Although in the Southern Hemisphere the Magellanic Clouds are visible to the unaided eye, they cannot be observed from the northern latitudes. The LMC is more than 150,000 light-years from the Earth and the SMC lies roughly 200,000 light-years away. Globular cluster NGC 1850 in the Large Magellanic Cloud. Most of the cluster N132D, remnants of a supernova in the Large Magellanic Cloud, as observed by the Hubble Space A knot in the central ring of Supernova 1987A, as observed by the Hubble Space Telescope The Magellanic Clouds were probably formed several billion years after the Milky Way system condensed from debris left behind by the big bang, a violent expansion of an intensely compressed single mass of material that is believed to have given rise to the universe. They contain numerous young stars and star clusters that were formed from nebulous clouds of pristine gas, as well as some substantially older stars. The Magellanic Clouds serve as excellent laboratories for the study of slightly retarded though very active stellar formation and evolution. They have also received more attention since the Hubble Space Telescope made it possible for astronomers to study star clusters, nebulae, supernovae, and other phenomena in the Magellanic Clouds that they could previously observe only in the Milky Way.