Crash of the Titans: Milky Way and Andromeda Galaxy

* From Video Source:

In this episode of the Hubblecast, scientists Jay Anderson and Roeland van der Marel show how they have used Hubble observations to predict the future of the Andromeda Galaxy and the Milky Way.

The Andromeda Galaxy, some 2.2 million light-years away, is the closest spiral galaxy to our home, the Milky Way. For around a century, astronomers have known it is moving towards us, but whether or not the two galaxies would actually collide, or simply fly past each other, remained unclear.

Now, a team of astronomers has used the Hubble Space Telescope to shed light on this question, by looking at the motion stars in the Andromeda Galaxy.

We wanted to figure out how Andromeda was moving through space. So in order to do that we measured the location of the Andromeda stars relative to the background galaxies. In 2002 they were in one place, and in 2010 they were in a slightly different place. And that allowed us to measure the motion over a period of eight years.