A swarm of comets orbiting the sun at a distance of one to two light-years, proposed as a source of comets that pass near the sun.
A spherical, moving mass of icy cosmic debris thought to exist in the vast region beyond Pluto and to be the source of the long-period comets that orbit the sun.
A sphere-shaped mass of more than 100 billion comets that makes up the outer edge of the solar system, surrounding the Kuiper belt and the planets. Some comets from this area are drawn into the inner solar system by passing stars and other forces and take more than 200 years to make one complete orbit of the Sun.
Origin of oort-cloud
- After Jan Hendrix Oort (1900–1992), Dutch astronomer
From American Heritage Dictionary of the English Language, 5th Edition
- Named after Dutch astronomer Jan Hendrik Oort.