People can get slightly better vacuum pressures in elaborate lab settings than are present on the moon. With trivial amounts of effort (and non-trivial sums of

People can get slightly better vacuum pressures in elaborate lab settings than are present on the moon. With trivial amounts of effort (and non-trivial sums of $), you can get within a couple orders of magnitude. Source: have done so myself. The difference is that space is filled with lots of other stuff that makes running experiments less than ideal.