SPACE PHOTOS THIS WEEK: Ghost of Mirach, Wet Mars, More

SPACE PHOTOS THIS WEEK: Ghost of Mirach, Wet Mars, More
    1 of 5   Next >>
October 30, 2008---The Bullet Cluster (above) was born of a violent collision between two other large galaxy clusters. It is a mix of dark matter and million-degree gasses that reside 3.8 million light-years from Earth.

Some astornomers theorize that the cluster holds antimatter from the Universe's earliest days.

But the x-ray output in this composite image (red), and a lack of observable gamma rays, suggests that the Bullet Cluster does not contain antimatter in significant amounts, according to NASA.
—Image by X-ray: NASA/CXC/CfA/M.Markevitch et al.; Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.
 
NEWS FEEDS    After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed. After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS




 

50 Drives of a Lifetime

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.