5 megaparsecs is over 16 million lightyears. That's 160 times the diameter of the Milky Way's disk, so it's not exactly close. I think Pete's just giving you a rough estimate. Sounds plausible, but I don't really know.
Originally Posted by Kevin Webb
Andromeda galaxy is about 2.5 million lightyears away, and apparently the expansion over that distance isn't enough to overcome the gravity between our galaxy and Andromeda, since it's blueshifted and coming this way.
The huge Virgo Cluster is the central player in the supercluster we belong to. A large elliptical galaxy near its center (M87) has a redshift of z=.004. The cluster is about 50 million lightyears away (17 Mpc) [there's a little controversy over the exact distance]. Wikipedia claims, "The large mass of the cluster has the effect of slowing down the recession of the Local Group [that's us] from the cluster by approximately ten percent." (I wouldn't take this as gospel, but it could very well be approximately correct.)
Might give you a little better idea of expansion vs. gravitation.
Everyone is entitled to his own opinion, but not his own facts.