Well, all of it is there. The party just barely makes it out of the crater on the highwind, in time to see Midgar starting to be torn apart from Meteor, then Holy comes, but it has the opposite effect and it seems to be destroying things along with Meteor/making Meteor even more powerful.

When it seems like this is it, the strands of the lifestream start gathering and coming out of the ground to prevent it, and they effectively stop Meteor. It proves Sephiroth's theory correct - that if there was an impending danger large enough to threaten the very life of the planet, the planet would gather a large amount of energy enough to repel it/heal the wound. Except for some reason, the place that this occured was Midgar, not the Northern Crater. This fact seems to raise a few questions.

Also, because it shows Aeris' face at the end, I think her becoming one with the planet/lifestream was how she intended to stop it, as she said before she ran off that she's the only one who can. I think this is why she let herself be killed by Sephiroth, she knew that she had to enter the lifestream/become one with the planet in order to stop Meteor, which she expected that Sephiroth would summon any day now.