OK, I've got a new question: If Jenova arrived on a Meteor that crashed into what is now the Northern Crater, why didn't Lifestream and/or Holy stop that one, which must have been much smaller than the one Sephy summoned, as otherwise it would've destroyed the whole planet. It's not as if they weren't any people to use Holy either - the planet was populated by loadsa Cetra.......I'm confused - maybe Jenova didn't actually arrive on a Meteor?