The Eskimo Nebula is a bipolar, double-shell planetary nebula (PN) in the northern constellation of Gemini. Alternatively, it is known as NGC 2392, Clown Face Nebula, Lion Nebula, or Caldwell 39. This feature was discovered by German-British astronomer William Herschel in 1787. NGC 2392 lies about 6,500 light-years away, and is visible with a small telescope. The formation resembles a person's head surrounded by a parka hood. It is surrounded by gas that composed the ejected outer layers of a Sun-like star. The visible inner filaments are ejected by a strong wind of particles from the central stellar remnant. The outer disk contains unusual, light-year-long filaments.