I know the Marvel Cinematic Universe likes to keep the locations vague to avoid questions like this, but it's been established by director James Gunn that the events of the Guardians of the Galaxy take place in the Andromeda Galaxy, not our local Milky Way. That suggests that locations such as Knowhere, Xandar, and Titan are in the Andromeda Galaxy, 2.5 million light-years away from the Milky Way. (For comparison, that's approximately 25 times the 100,000-light-year diameter of the Milky Way.)
Given that, we seem to have a scramble of locations in Infinity War:
- The Asgardian refugee vessel(s), which left the ruins of Asgard (location unspecified) and from which Heimdall sent Hulk to Earth.
- Thanos then dispatches his minions to Earth.
- The Guardians, who are nominally in Andromeda, respond to the distress call from the Asgardian refugees and pick up Thor.
- Some Guardians go to Knowhere in the Benatar (the Milano's successor), while others go to Nidavellir via a pod. (Isn't Nidavellir supposed to be in its own realm?)
- Tony Stark, Peter Parker, and Doctor Strange wind up on Titan after a what seems like a relatively short trip.
- Thor and Thanos wind up on Earth, but their instantaneous travel is explained by either bifrost powers or the Space Stone.
Did Infinity War directors Anthony and Joe Russo retcon James Gunn's distinction between the two galaxies, or did they simply fuzz everything over?
Is there an MCU or out-of-universe answer?