Get Ready: Milky Way to Collide With Neighboring Galaxy in 4 Billion Years

A visual guide to what the cosmic event will look like from space -- and from right here on Earth.

654283main1_i1220bw-673.jpg

NASA

The Andromeda galaxy is about 2.5 million light years away -- for now.

NASA scientists announced yesterday that Andromeda (also called M31) and our own galaxy, the Milky Way, are on a collision course that will result in a dramatic rearranging of the two galaxies that will begin in about four billion years and last for another two billion. In the end, the two galaxies will merge completely into a single elliptical galaxy. A third galaxy, M33, may join in the collision, and, possibly, even reach the Milky Way first.

It had long been known that Andromeda is rushing towards Earth at about 250,000 miles per hour -- or about the distance from Earth to the moon -- but scientists were unsure whether the two galaxies would full-on collide or just barely brush. The new research is the result of careful observations of Andromeda by the Hubble Space Telescope, which show that the gravitational pull of each galaxy is pulling them closer and closer together, and "remove any doubt that [M31] is destined to collide and merge with the Milky Way," NASA said. The sun could end up in a completely different region of the galaxy, one much farther from the galactic center, but that the Earth and solar system would survive.

These sorts of collisions were more common in the early universe, when the universe was smaller, but they still happen because of the gravitational pull of dark matter.

NASA has provided artistic renderings of what the whole event -- unfolding over billions of years -- will look like from here on Earth:


In addition, a video shows the trajectory of the two galaxies and how the collision will appear from space:

To learn more about how scientists measure distances of light years in space, we have an explainer video up here.

Presented by

Rebecca J. Rosen is a senior editor at The Atlantic, where she oversees the Business Channel. She was previously an associate editor at The Wilson Quarterly.

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register with Disqus.

Please note that The Atlantic's account system is separate from our commenting system. To log in or register with The Atlantic, use the Sign In button at the top of every page.

blog comments powered by Disqus

Video

The Absurd Psychology of Restaurant Menus

Would people eat healthier if celery was called "cool celery?"

Video

This Japanese Inn Has Been Open For 1,300 Years

It's one of the oldest family businesses in the world.

Video

What Happens Inside a Dying Mind?

Science cannot fully explain near-death experiences.

Video

Is Minneapolis the Best City in America?

No other place mixes affordability, opportunity, and wealth so well.

More in Technology

Just In