system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Exactly how fast does Mjolnir travel when Thor summons it? Does it have a summoning range?

Whenever we've seen Thor summon Mjolnir, sometimes it takes a moment to travel to his hand. Does it have a set speed? Can Thor increase or decrease its speed at will? If he went to Earth and forgot it on Asgard, how long would it take to get back to him?

Also, is there a set limit for how far he can summon it? If he did forget it on Asgard, is it now too far and he'd have to get closer to Asgard?
gpt
To add into the other comment about Thor 2, that film gives us the only clue as to Mjolnirs actual flight speed — it gets from a high orbit back to the UK in about five seconds. That was probably from an altitude of about 400 miles at a quick guess, so say at least 250,000mph.