Radio emission by ionized atoms reveals structures and details about our universe that escape visual observers. The image at left shows three galaxies, M82, M81 and a companion. From the optical image it is not clear whether these galaxies are at the same distances, nor is there any sign of interaction. When viewed at radio wavelengths these objects are clearly linked into a single, interacting galactic cluster. The radio image clearly shows the tidal forces of giant M81 striping gas from it companions. It this tidal disruption that may be the cause of the bright knots of star formation in M82. The tidal disruption may have dump fresh material into the black hole at the center of M82 that feeds prominent jets. Additionally, note how much larger all of the galaxies are than you would believe based solely on their luminous matter.