Interacting Galaxies Arp 220
Observed in 2006
Arp 220 captures the dramatic aftermath of a cosmic collision between two spiral galaxies that began approximately 700 million years ago. This ongoing galactic merger, located about 250 million light-years from Earth, is one of the nearest examples of interacting galaxies to our planet, making it an invaluable laboratory for studying galactic evolution. The collision has triggered intense bursts of star formation as gas clouds from both galaxies compress and ignite, creating what astronomers classify as an ultraluminous infrared galaxy—one of the brightest objects in the infrared sky. The chaotic tangle of stars, gas, and dust showcases the violent yet creative forces at work during galactic mergers, offering a preview of what may occur when our own Milky Way eventually collides with the Andromeda Galaxy in several billion years.
Image credit: NASA, ESA, Hubble Space Telescope