First Direct Proof of Dark Matter
Whirling around Earth at 17,500 miles (28,163 kilometers) an hour, the Hubble Space Telescope
has captured some of the most detailed pictures yet of space objects and activities.
But Hubble is about much more than pretty pictures. Using its data, researchers have made giant leaps in unraveling mysteries of the universe.
In honor of the telescope's 19th birthday--April 24, 2009--NASA has released its list of the top 12 science discoveries made using Hubble pictures, including this picture of the so-called Bullet Cluster.
Combined with data from two other telescopes, Hubble's view of the cluster shows what happens when two large groups of galaxies collide. The image was hailed in 2006 as the first direct proof of dark matter
, a still unidentified substance thought to make up most of the total mass of the universe.
X-ray image courtesy: NASA/CXC/M.Markevitch et al.; Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.