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.(In general use) any indistinct bright area in the night sky, for example, a distant galaxy.
On a clear night you might be able to see a nebula without the help of a telescope.Long before modern science, astronomers have been fascinated by the comets, nebulas, and stars in the night sky.
