Hubble's Greatest Hits - Billows of cosmic dust swirl amid NGC 1316, a giant elliptical galaxy formed billions of years ago when two spiral galaxies merged. Astronomers examined red star clusters within NGC 1316 to determine that the massive galaxy was indeed created by a major celestial collision.
Trigger-Happy Star Formation (NASA, Chandra, 8/12/09). his composite image, combining data from the Chandra X-ray Observatory and the Spitzer Space Telescope shows the molecular cloud Cepheus B, located in our Galaxy about 2,400 light years from the Earth. A molecular cloud is a region containing cool interstellar gas and dust left over from the formation of the galaxy and mostly contains molecular hydrogen.