Latest Issue of Science News


Separation Anxiety: Cosmic collision may shed light on dark matter

Some 3 billion years ago, two massive clusters of galaxies collided head on. The debris from this ancient cosmic train wreck, astronomers say, might pose a new puzzle about the invisible material believed to account for most of the mass in the universe.

A variety of evidence indicates that this material, known as dark matter, is about eight times as abundant as ordinary matter and that it resides in vast, invisible halos around star-filled galaxies. Dark matter keeps galaxies and galaxy clusters intact, theorists say.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

This article is available only to subscribing members. Join SSP today or Log in.