Empty space in outer space is not truly empty. Celestial objects fill the space not occupied by planets, stars, and such. This resource identifies these objects and further explains their existence.

This video segment adapted from NASA uses animation to illustrate the properties of meteor showers and comets. Included is are visualizations of a comet's tail and of Earth passing through a debris stream left behind by meteoroids.

Under the heading, "Comets Kick up Dust in Helix Nebula" this site a particular nebula in the constellation Aquarius. In addition to an image, the site provides information on nebulas and star systems.