Arp 87: Merging Galaxies from Hubble . ... Along the way, as these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. ... As further evidence, the face-on spiral galaxy on the right, also known as NGC 3808A, exhibits many young blue star clusters produced in a burst of star formation. ... The prominent edge-on spiral at the far left appears to be a more distant background galaxy and not involved in the on-going merger. ...