But he does not run away from me on an alien planet.

To me, it was like reading about life on an alien planet.

The game takes place on the surface of an alien planet.

The men had seen too many alien planets to pay much attention to this one.

To the first alien planet you or I ever set foot upon.

Have you been living on some alien planet for the past decade?

This was, after all, the first time he'd ever set foot on an alien planet.

"I have very little experience with alien planets," he said.

He looked like the last person on Earth who knew what to do when meeting up with a vessel from an alien planet.

Some alien planets may have more than one research building constructed.