Astronomers have spotted a rare, complex cosmic collision of four galaxy clusters. A spectacular composite image from NASA's Chandra X-Ray Observatory and Hubble Space Telescope revealed the pileup—and its likely source.

To understand how the modern Universe came to be, astronomers turn to computer models, programs that follow the physical laws of the Universe. Scientists use these models to understand the formation and evolution of galaxies and quasars in the universe.

Explore the 2MASS Galaxy Catalog in Digital Universe.