Scientists members of an international team led by Australian National University researcher Dr Dougal Mackey and University of Sydney Professor Geraint Lewis discovered that the Milky Way is on a collision course with Andromeda in about four billion years.
„Andromeda has a much bigger and more complex stellar halo than the Milky Way, which indicates that it has cannibalized many more galaxies, possibly larger ones," said Dougal Mackey, a fellow at the Australian National University's Research School of Astronomy and Astrophysics. He co-led the international study that discovered Andromeda's eating habits. Researchers followed a trail of astronomical crumbs to find globular clusters of stars that once belonged to other galaxies within Andromeda. The researches realized that the Andromeda galaxy consumed other galaxies in different directions.
Andromeda’s history of galactic cannibalism could stretch back as far as 10 billion years. At the time when the predicted collision will happen, it's possible that the Sun could be thrown out of the merged Andromeda and Milky Way system by the collision, into intergalactic space, and/or a nearby close passage with another star could perturb the Earth's orbit such that the Earth can no longer support life. The findings were published in British scientific journal Nature.