Cosmic Fireworks (also known as When Galaxies Collide) (Free Astronomy Public Lectures)

Studying galactic interactions is like sifting through the forensic evidence at a crime scene. Astronomers wade through the debris of a violent encounter, collecting clues so that they can reconstruct the celestial crime to determine when it happened. Take the case of Messier 82, a small, nearby galaxy that long ago bumped into its larger neighbour, Messier 81. When did this violent encounter occur? New infrared and visible-light pictures from the Hubble Space Telescope reveal for the first time important details of large clusters of stars, which arose from the interaction. The talk focuses on the train wrecks resulting from galaxy collisions and the implications for us in the Milky Way