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nebula

nebula:

A cloud of stars or dust and gases in deep space. Galactic nebulas are clouds of dust in our own galaxy, the Milky Way. They may be dark or the gases may be lit up by surrounding stars. Extragalactic nebulas are galaxies of stars beyond the Milky Way. Some kinds of nebulas may be the birthplaces of stars. [Nebula comes from a Latin word meaning “mist” or “fog.”]