@Matt I'll agree on the expansion bit, but I'm pretty sure the face remained stationary the whole time, and plus a face isn't "an entire Moon". Nor is the geothermal energy of a Moon equal to it's GBE (or anywhere near it).
It doesn't really matter if Thor's hammer having a bunch of speeds is ridiculous to you, because that's what we see. In the first scene it appears it returns to him twice as quickly as he threw it and in the scene with Malekith he throws it at subsonic speed only for it to turn up, break the sound barrier (complete with SFX to show that) and accelerate to Mach 100 in seconds.
And no matter how many times you insist, Rocket's ship wasn't flying at 100 m/s or else it wouldn't enter a planet's orbit in seconds. And unless you have specific proof that the jetpacks can't reach the Mach 20+ speed in combat, which you haven't, you can't insist that the Guardians can't fight at Mach 20+ speeds and react, specially when it is consistent with Rocket's reactions.
Being able to enter a planet's orbit doesn't suggest high speed. You can let gravity do that. If you mean
exiting a planet that doesn't require high speed either. You can do that at 1 m/s.
As for my proof the jetpacks weren't moving at Mach 20:
- There was no sonic boom (Even though we know the SFX animators know how to make those from Thor)
- They didn't look like they were moving at Mach 20 in any of the combat scenes (So assuming otherwise is speculation and would require evidence to back it up)
- Gravity wasn't operating any slower than normal (If the scene was slowed to be showing Mach 20 at perceivable levels, why wasn't anything in the environment moving any slower)
- There is no verbal indication they're moving very quickly
- There is no audio indication they're moving quickly (Sound from slower things being slowed/muffled)
- We have no indication that they would even want to be moving at Mach 20 speeds (There's no external evidence they can react that fast)
So basically, there's no indication they're moving that fast in any of the combat scenes with the jetpacks. Therefore it's a lot more likely that the jetpacks have an acceleration time like real flying objects do or that the Guardians just aren't using them at max speed to avoid flinging themselves into the horizon rather than that the scenes are secretly playing at 1/100th real time without showing anything to suggest that.