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."

a piece of the RAS.ORG.UK article:

"Most cosmologists believe that across the whole universe, this matter outweighs ‘normal’ matter by a factor of five. The dark matter in both Andromeda and the Milky Way then makes the gravitational pull between the two galaxies strong enough to overcome the expansion of the cosmos, so that they are now moving towards each other at around 100 km per second, heading for a collision 3 billion years in the future."

Two articles about this:

Article 1. (Ras.org.uk)

Article 2. 

SCIENCE: WE find out everyday how wrong we were the day before. I love it! (it's the most efficient tool that we as humans have at our disposal for making sense our the world around us.)