Dark Matter Revealed
A powerful collision of galaxy clusters has been captured by NASA's Hubble Space Telescope and Chandra X-ray Observatory. The observations of the cluster known as MACS J0025.4-1222 indicate that a titanic collision separated the dark from ordinary matter. Using visible-light images from Hubble, the team was able to infer the distribution of the total mass -- dark and ordinary matter. Hubble was used to map the dark matter (colored in blue) using a technique known as gravitational lensing. The Chandra data enabled the astronomers to accurately map the position of the ordinary matter, mostly in the form of hot gas, which glows brightly in X-rays (pink).