Did Andromeda crash into the Milky Way 10 billion years ago?

The Milky Way Galaxy,  composed roughly out of 200 billion stars, a part of a group of galaxies called the 'Local Group'. Astrophysicists theorise that most of the mass of the Local Group is invisible, made up of so-called 'dark matter'.


"For many years scientists have believed that our Galaxy, the Milky Way, is set to crash into its larger neighbour, the Andromeda Galaxy, in about 3 billion years’ time and that this will be the first time such a collision has taken place. But now a European team of astronomers led by Hongsheng Zhao of the University of St Andrews propose a very different idea; that the two star systems collided once before, some 10 billion years ago and that our understanding of gravity is fundamentally wrong."