As showcased in this Hubble image of a small, outer part of the Andromeda galaxy, background galaxies can be seen through the halo of Andromeda. Thousands of such galaxies have been discovered, many of which are in various stages of mergers and acts of galactic cannibalism. (NASA, ESA AND T.M. BROWN (STSCI))

These Are The Last Galaxies That Will Remain In Our Night Sky

Billions of years from now, dark energy will push the rest of the Universe out of reach forever. These galaxies will be the last to go.

A look at the night sky, near and far, reveals galaxies everywhere we look.

Hubble’s advanced camera for surveys identified a number of ultra-distant galaxy clusters. If dark energy is a cosmological constant, all of these clusters will remain gravitationally bound themselves, like all galaxy groups and clusters, but will accelerate away from us and one another over time as dark energy continues to dominate the Universe’s expansion. (NASA, ESA, J. BLAKESLEE, M. POSTMAN AND G. MILEY / STSCI)

Throughout the entire observable Universe, an estimated two trillion galaxies exist.

Our Local Group of galaxies is dominated by Andromeda and the Milky Way, but our cosmic neck-of-the-woods contains many dwarf galaxies clustered around each of the large members. Triangulum is the 3rd largest. The Large Magellanic Cloud is the fourth biggest galaxy in the local group, with a slew of others, including M32, between 0.1% and 0.6% the Milky Way’s mass. Approximately 72 galaxies exist in our Local Group in total. (ANDREW Z. COLVIN)

Our Local Group, dominated by Andromeda and the Milky Way, houses about 70 galaxies total.

Different stills from a simulation of the merger of the Milky Way and Andromeda galaxies. When a major merger like this occurs, it may be the case that a large amount of debris is kicked up, creating satellite galaxies dominated by normal matter. The merger will complete in approximately 7 billion years, and the other Local Group galaxies will join on a variety of timescales. (NASA, ESA, Z. LEVAY, R. VAN DER MAREL, T. HALLAS, AND A. MELLINGER)

Over cosmic timescales, gravity will merge us all together into a single, enormous elliptical galaxy.