Mysterious New 'Dark Flow' Discovered in Space

From Space.com (Sept. 2008):

As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered.

Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow."

The stuff that's pulling this matter must be outside the observable universe, researchers conclude. [read more]

I know this blog entry is old, but I only heard of this phenomena in October 2009 issue of Popular Science. No-one knows for sure why the phenomena is happening. One theory is that a parallel universe is causing the motion.