In the Star Trek: The Next Generation episode "Schisms", the USS Enterprise-D charted a globular cluster, the Amargosa Diaspora . It is said that starship navigation within a globular cluster can be difficult because of gravimetric interference.

In actual fact, a globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. As opposed to open clusters, globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. A globular cluster is sometimes known more simply as a globular.

Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk. Globular clusters are fairly common; there are over 150 currently known globular clusters in the Milky Way. Large galaxies can have more: Andromeda, for instance, may have as many as 500. Some giant elliptical galaxies, such as M87, may have as many as 10,000 globular clusters.

The Andromeda Galaxy