About 290 million light-years distant,[2] they have begun the process of colliding and merging.

Their "mice" name refers to the long tails produced by tidal action—the relative difference between gravitational pulls on the near and far parts of each galaxy—known here as a galactic tide.

It is a possibility that both galaxies, which are members of the Coma Cluster,[3] have experienced collision, and will continue colliding until they coalesce.

In NGC 4676A a core with some dark markings is surrounded by a bluish white remnant of spiral arms.

The tail is unusual, starting out blue and terminating in a more yellowish color, despite the fact that the beginning of each arm in virtually every spiral galaxy starts yellow and terminates in a bluish color.