This video shows Hubble Space Telescope observations of Arp 116, a pair of galaxies in the constellation Virgo. Arp 116 is composed of a giant elliptical galaxy known as Messier 60 (or M60) and a much smaller spiral galaxy, NGC 4647.
Astronomers have long tried to determine whether these two galaxies are actually interacting. Looking at them from Earth they overlap, but there is no evidence of new star formation, which would be one of the clearest signs that the two galaxies are indeed interacting. However, recent studies of very detailed Hubble images suggest the onset of some tidal interaction between the two.
Publication: September 6, 2012