I think this settles it for where the purple haze cannot
be in Where No Man Has Gone Before
KIRK: That's probably the best argument to continue the probe. Other vessels will be heading out here someday and they'll have to know what they'll be facing. We're leaving the galaxy, Mister Mitchell. Ahead, warp factor one.
SPOCK: Force field of some kind.
It cannot be inside the galaxy, as I said.