While I generally like what Ginny has to say, I found the early (0.x) editions of Mothership annoyingly cluttered and hard to parse. Never gave it much thought after. Thus I'd skipped this one.
Generally, my horror of choice is Alien (Year Zero engine, d6 version.) Tho' my group and I found the adventures for Tales from the Loop equally horror laden. (it's also usurped Traveller for my space trucker or Merc gaming desires.)
The Transgression, Omen, Manifestation, Banishment, Slumber modality is nifty, but Alien has similar, if less cutely named advice.