Veering a bit off topic but related to Dutch Ghost's post, how did Weyland-Yutani know to send the Nostromo to LV426? Does Ash's special order confirm that they already knew about the alien? And why didn't they send a dedicated explorer, scientific or military vessel instead?
I'm sure I must be the millionth person to ask this, and having been around the AvP community for a decade and a half, you'd think I'd have picked it up by now.