The Chicxulub Asteroid that killed the dinosaurs is magically redirected towards Pandora (James Cameron's Avatar franchise). How screwed is Pandora?

In a parallel universe, the killer asteroid that caused the Cretaceous-Paleogene Extinction Event is magically knocked off course and instead hurtles towards (and eventually hits) Pandora (Avatar franchise).

Edit: Assume there’s no wormhole speeding up its arrival time and it takes billions of years for the asteroid to reach Pandora.

How screwed are the inhabitants of Pandora? Can they bounce back from this extinction-level event (if at all)?