andromeda galaxy

The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way and is one of only ten galaxies that can be seen unaided from the Earth. In approximately 4.5 billion years the Andromeda Galaxy and the Milky Way are expected to collide. Andromeda is accompanied by at least 10 satellite galaxies the most notable of which is the Triangulum Galaxy.

Galaxy Profile

  • Type: Spiral
  • Distance from Milky Way: 2.5 million light-years
  • Diameter: 260,000 light-years
  • Mass: 400 billion solar masses
  • Number of Stars: 1 trillion

Facts about Andromeda

  1. While Andromeda is the largest galaxy in the Local Cluster it is not thought to be the most massive as the Milky May is thought to contain more dark matter making it the most massive
  2. The Andromeda Galaxy is approaching the Milky Way at approximately 100 to 140 kilometres per second