M66 is a spiral galaxy that is a
member of the famed Leo Triplet group, which also contains M65 and
NGC 3628. M66 is an intermediate spiral galaxy that appears to have
been affected by the gravitational fields of its neighbors. That
is, it has central mass high concentration and a non-corotating
section of H1 material that was pulled from one of its arms.
M66 was discovered by Charles Messier
in 1780. It is estimated to lie 35 million light years away and
have a diameter of 90 thousand light years.