Corrected entry: In the scene where we see the Moonbus landing at the Tycho Excavation Base, its descent engines raise dust that billows rather than falling in an arc straight back to the ground as would normally be the case in a vacuum. (00:50:35)
fweddy
19th Jul 2010
2001: A Space Odyssey (1968)
Correction: Dust particles will billow out in the manner we see if they have gas molecules to bounce off. Normally on the moon they have no such thing but in this case they do - the exhaust plume of the landing spacecraft. Until it slowly dissipates it will react with the dust molecules just like an atmosphere does.
Correction: Previously posted and corrected. This is an accepted film technique, not a mistake. You cannot film in a vacuum.
Vacuum chambers certainly existed at the time. NASA tested Apollo spacecraft in them. It may have been difficult, but it certainly would have been feasible to film models in a vacuum at the time. Further, why should an "accepted film technique" forgive an obvious mistake in physics. If anything, it would be an intentional mistake if there was no way to simulate the effect of dust in a vacuum.
Vader47000