Yeah, if you check out the meteor clip on the VisionLab product page you can see it in some more detail. Alternatively, here's a hi-res version:http://fxhome.com/press/files/Movies%20Samples/Compositing%20comet%20
Here's an overview of what's going on:
• Grading objects - one to create the impact crater/wound in the ground. Another one for the dark 'hole' in the cloud where the meteor appears from. Finally another one to give the entire shot the warm firey glow.
• Storm cloud - large, dense particle effect positioned top left and masked to go behind the trees a bit.
• Impact explosion - mixture of firey stock footage from Sollthar's collection, timed to go off when the meteor hits. Masked to go behind the foreground trees.
• Impact debris - Particle effect to splay out extra 'dirt' from the explosion. Carefully tweaked gravity and a wide angle emitter.
• Comet trail - large smokey particle effect, masked so that it only appears in the thin, trailed line.
• Comet head - two pieces of firey stock footage from Sollthar's collection, animated to zoom in from the top left.
• Background plate - still image of the forest mountains.