Crashed vast ancient UFO in Antarctic snow field

They're UFOs, and they all totally crashed in the snow. Because their condenser coils froze. And then the aliens inside froze because they couldn't restart their fusion drives. What makes all this a little less sad is that a) three of the four alien species don't have individual consciousness, b) all four were up to no good, and c) one of the crash sites will eventually get discovered by a human explorer and a lot of exciting advances will result including finally understanding what the Voynich manuscript is about and who wrote it.