I know it's the long way around, but have you thought about animating some low-res geometry to get your animation timing right, then:

1. substitute the meteor with the meteor fluid, and match the low-res animation
2. render JUST the meteor.
3. then render just the nuke.

Then, composite them together later.

Sorry, I know it's the long way around, but untill they allow us to mix fluids, the interaction that you want, you may have to fake a bit...