heygeorge

One thing is certain: Definitely aliens.

VoutGuy

Maybe they didn't crash; instead they dug up a whole continent. If you're zooming around space with a 200 miles UFO, you must plan on transporting stuff.

8_billion_eaters

With a 200 mile wide spaceship, you have achieved independence for your people. You are your own (separate, but equal) civilization. Wouldn't that be cool?