The Galaxy (or 'the galaxy') is the common name given to the galaxy in which the Space Quest games take place.
But the occasional reference may suggest that individual games may take place in the Andromeda Galaxy or even the Milky Way. See Milky Way Today (inflight magazine of the Star Confederation) and Popular Janitronics (published on Earth).
The Earnon Galaxy and Andromeda Galaxy may possibly be double galaxies with connecting arms and thus may be considered a special type of Galaxy.
Behind the scenesEdit
Throughout most of the games and manuals its implied that Roger Wilco remains in the same galaxy, usually simply called "the galaxy". The only exception is the short scene at the end of Space Quest III in which Roger travels through a black hole to a location near the planet Earth in the Milky Way galaxy (and also possibly within the Milky Way during the events of SQ6). Earth itself is treated being in the Milky Way and sometimes within a parallel universe beyond time and space (time travel may involve parallel travel between alternate universes).
The manual for SQ3 suggests that the Two Guys are from the Andromeda System and its implied that its likely within 'the galaxy' and possibly not far from the sector's visited in that game (as the family discusses taking a vacation to Phleebut). Thus they probably didn't travel very far when they were kidnapped by the Pirates of Pestulon. Although technically the news report may have been broadcasted in multiple galaxies.
In SQ3, it is said that the rack in Fester's shop has postcards from around the galaxy. However in the Space Quest Companion, his cards also include Terra III and SidneyLand, which are definitely outside the galaxy, all the way the Milky Way (albeit both galaxies are connected through the local Blackhole). The rack also contains places such as GullyFoyle IX, Kerona, the Black Hole of Oakhurst, Black Hole Bertha, Achoron, Ortega, RobertaLand, Beta Alpha Starless Region, Arakkis, and presumeably Nimbus III, and Hair Island. This would imply that all the latter lie in the same galaxy. As Kerona is in the Earnon galaxy, it would imply that the games are in the same galaxy as SQ1 and SQ2. Or however based on the various references to Andromeda, it could imply that the game takes place in the Andromeda galaxy (which would suggest Kerona is in Andromeda). On the other hand it could also suggest that Earnon and Andromeda are alternate names for the same galaxy, or that both galaxies are near each other or overlap (double galaxies with connecting arms, or interacting galaxies). Or perhaps Roger (or the narrator) wasn't paying attention and didn't notice that the rack contained more than sites within the galaxy, but from several galaxies.
In Galactic Inquirer; the galaxy is referred to as simply "the galaxy", whereas it refers to the Milkyway galaxy (aka Milky Way) seperately and mentions that it is the cesspool of the universe and can be reached through the Mondorian blackhole. There are at least two direct references in the manual to the Milky Way within two articles. Although many locations within Milky Way are alluded to (mostly Sol system locations).
The Galactic Inquirer alludes to Andromeda suggesting that its "far off", suggesting a seperate galaxy. Andromeda is referred to in two separate articles, including in an expose on Mark Crowe and one concerning an alien that died from deadly nose hair pluck. Andromeda is also mentioned in an advertisement for a nose hair trimmer. But Andromeda appears to be used in different ways depending on the context, and may refer to the planet, the system or galaxy. The context of the mention of Andromeda in the Mark Crowe expose article suggests the galaxy. The reference in the nose hair trimmer advert is specifically the planet Andromeda. The article about the Andromedan who dies from nose hair pluck, has both references to the planet, but also the system/galaxy (the context is unclear for the latter).
A reference made in the Space Quest Companion suggests that SQ5 takes place in another galaxy other than Andromeda (in line with what Galactic Inquirer implies). For example its stated that SpaceMonkeys are the cutest micro-pets between "here and Andromeda". A reference in the Galactic Inquirer also suggets that events of SQ1 and events surrounding 'StarCon star generator' occured in the same galaxy in which SQ5 takes place (it may also suggest that Xenon is the location of StarCon Central Command), thus suggesting that the game takes place in the Earnon Galaxy.
A reference in SQ6, to StarCon's inflight magazine Milky Way Today may suggest that that game takes place in the Milky Way or that StarCon's base of operations in that game is in the Milky Way. The game simply refers to galaxy in which the game takes place as "The Galaxy" (or 'the galaxy'). Popular Janitronics which was included with SQ6 also refers to 'the galaxy' but since the magazine is published on Earth, it would suggest that the magazine is referring to the Milky Way galaxy (which also may supports that the SQ6 takes place in the Milky Way).
Additional references in the Space Quest Companion, and The Official Guide To Roger Wilco's Space Adventures may also suggest a few of the games taking place within the Andromeda galaxy, or at least the Two Guys having originated from Andromeda galaxy. This just adds to the confusion. For example the Official Guide mentions that popular Xenonian television reaches from Andromeda to the Milky Way (thus the context appears to be television reaching between two galaxies).