... The Tidal Tail of NGC 3628 . ... Credit Copyright: Thomas V. Davis ( tvdavisastropix.com ) Explanation: A mere 30 million light-years away, large spiral galaxy NGC 3628 (center left) shares its neighborhood in the local Universe with two other large spirals , in a magnificent grouping otherwise known as the Leo Triplet . ... Know as a tidal tail , the structure has been drawn out of the galaxy by gravitational tides during brief but violent past interactions with its large neighbors. ...