A nebula is a gigantic space cloud of dust and gas. Several nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a star that is dying, like a supernova. Other nebulae are giant celestial dust clouds where new stars are starting to form. Nebulae are made of dust and gas—mostly hydrogen and helium.
True because the definition of a Nebula is a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
