Attached Link: http://www.dexfx.com/Effects.htm

This is a sample expolosion from Particle Illusion which Hotsteppa mentioned above. It's an amazing piece of software.

For this shot (these are four stills from an animation), I used Particle Illusion for the explosion, Carrara for the flying saucer and some debris, and Adobe AfterEffects to do the compositing and to create some of the debris of the mission tower collapsing.

If you want to see the whole animation (it's actually not the most recent version, but I haven't posted anything to my site for a while), check out this link:
http://www.dexfx.com/Effects.htm

Hope that's helpful.

• Dex