If a Apollo type Moon mission happened today would we be able to see it transit in Lunar orbit? I know we can't see the Landing sites of the Apollo but could we see the Command Module and its shadow orbiting the moon?
Let's assume you are not only looking with your eyes, but Hubble Space Telescope. HST has a resolution of about 0.05 arcseconds, or 2.424068e-7 radians. The Moon is about 384,400 km. That comes to be about 100m, just to see it as a resolved dot.
Now, one could theoretically see an unresolved dot that is smaller, but it would be extremely difficult with a noisy background like the Moon present.
What would be more likely is if a major propulsive event happened that wasn't behind the moon, it might be able to be seen. Still, that isn't very likely.