Galaxies don't crash into one another as often as they used to. That's why scientists were so thrilled when they discovered this head-on collision and observed the results of the galactic smack-up – the creation of more than 1,000 bright, young star clusters. Star clusters are groups of stars born at almost the same time and place, and live together as units for billions of years because of the mutual gravitational attraction of their member stars. By studying the so-called Antennae galaxies, scientists hope to understand the evolution of colliding galaxies and why some galaxies are spiral shaped and others are elliptical or round. They also hope to get a better idea of how star clusters evolve, too. They once thought that these star-packed objects were the relics of the earliest generations of stars. It now appears that star clusters begin in giant molecular clouds that are squeezed by hot gas heated during a galactic collision. These clouds then light up in a great burst of star formation almost like a string of firecrackers. The Antennae galaxies, located 63 million light-years away in the constellation Corvus, got their unusual name because they have a pair of long tails of luminous matter that look like an insect's antennae.