Although... never underestimate the damage a blunt bludgeoning object can do. This is especially the case in a high-tech setting where you can accelerate large objects up to a significant fraction of the speed of light.

If you run the numbers, you find that it's much more efficient to bombard a planet with big rocks from orbit than to do any other sort of planetary attack or invasion. Assuming hostile aliens really want to wipe us out, that'd be their best modus operandi by far.

Imagine running this as a game scenario. Not your typical alien invasion, fighting bug-eyed monsters on the ground or in the air - instead they just implacably launch asteroids at Earth from the safety of the Moon or further away. The only way to fight them is get someone up there before all launch capability (and the entire biosphere) is wiped out, and perform some sort of infiltration mission.

Transcript

GM: Princess, you and Wicket emerge from the afternoon seminar to this horrible spectacle.
Leia: Stop. These are my... business partners.
Logray: I'm afraid they're now insolvent. It's time to divest and consolidate.
Han: Luke, I have a plan. Use the Force to animate your sword and slaughter these fuzzy free market fanatics.
Luke: Um...
C-3PO: I have a better plan. Use your Force powers to levitate me.
Luke: How will that help?
C-3PO: Just do it.
Luke: I don't understand, but okay.
Han: I think my plan would do a lot more damage.