NOTE: This Page Contains informations about Nebulas not clouds A nebula (from Latin: "cloud" (External Link); pl. nebulae or nebulæ, with ligature or nebulas)'s an interstellar cloud of dust, hydrogen gas, helium gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way (some examples of the older usage survive; for example, the Andromeda Galaxy was referred to as the Andromeda Nebula before galaxies were discovered b… (More on Nebula)