If I recall, Chrichton is an astronaut. (I think I've seen the equivalent one episode of Farscape, total.)
As such, he should be familiar with stellar objects.
Can he not surmise that he is in a distant part of the universe if the galaxies he can see (aided, obviously) are unfamiliar?
Actually, he wasn't just an astronaut/test-pilot, but was also the physicist who developed the wormhole tech. (his run in the module was not supposed to "work", just generate some low level er... pre-wormhole data to get some confirmation of his theories.)
So, yeah, a guy like that could probably be smart enough to look for a few notable galaxies/Messier objects or the Megelannic clouds using Moya's and Pilot's help to at least make an educated guess if he was still at least in the Milky Way. Even looking at the central black hole in the core might give him some clues. Even with our primitive 21st century tech we have
"movies" of the stars orbiting the central black hole.
http://www.youtube.com/watch?v=fE_uPcRV5hE&NR=1On top of that, there's a few objects in the galaxy that are visible in some wavelength or another from most anywhere in the galaxy unless the core is directly in the way. A couple of starbursts due galactic north/south to get above/below the disk for a better view would make this even easier.