Milky Way and Andromeda Galaxies to Collide in 4 Billion Years

Posted on June 1, 2012

NASA astronomers say our Milky Way galaxy will collide with the neighboring Andromeda galaxy in four billion years. The Sun will get flung into another part of our galaxy, but our Earth and our solar system will survive the galaxy collision. The above image depicts a view of the night sky just before the predicted merger between the Milky Way and Andromeda galaxies. You can see a larger version of the image here.

The astronomers came to the conclusion through painstaking NASA Hubble Space Telescope measurements of the motion of Andromeda, which also is known as M31. Andromeda is now 2.5 million light-years away, but it is inexorably falling toward the Milky Way under the mutual pull of gravity between the two galaxies and the invisible dark matter that surrounds them both.

Roeland van der Marel of the Space Telescope Science Institute (STScI) in Baltimore, says, "Our findings are statistically consistent with a head-on collision between the Andromeda galaxy and our Milky Way galaxy."

Astronomers created this animation that depicts the collision between our Milky Way galaxy and the Andromeda galaxy in about 4 billion years. Take a look:

The astronomers also say the Triangulum galaxy, M33, will join in the collision and perhaps later merge with the M31/Milky Way pair.

Here's a video about the collision from PBS Space Time:

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