The Hubble Space Telescope celebrated its 32nd birthday on April 24. To mark the occasion, NASA shared a spectacular image of a cluster of five galaxies known as the Hickson Compact Group 40.
The Hickson Compact Group 40 captured by Hubble consists of three spiral-shaped, one elliptical, and one lenticular (lens-like) galaxy.
In the course of their journey through the universe, their paths crossed, and they are now are falling together in a gravitational dance until they inevitably merge. Notably, this close-knit collection of five galaxies is so crowded it could fit into a region of space less than twice the diameter of our Milky Way.
A distinctive feature of the Hickson Compact Group 40 is its isolation. Though such groupings can usually be found in the centers of huge galaxy clusters, the Hickson Group is isolated in its small patch of the universe. According to astronomers, this is because the galaxies are bound by a large amount of dark matter.
The distance between the galaxies in the group is gradually decreasing, and in about a billion years, they will eventually merge into one giant elliptical galaxy.