- For other meanings of the word Galaxy, please see Galaxy (disambiguation).
A galaxy is a grouping of stars, usually densely, with interstellar dust and gasses, dark matter and other astronomical phenomena, held together by powerful gravitational forces. There are estimated to be one hundred billion galaxies in the visible universe. Due to scientific restrictions in traversing the vast distances between galaxies, most lifeforms known to the Federation and other governments are limited to our home galaxy, the Milky Way. Several exceptions to this have occurred over the years.