Sry i had to really compress it so i could upload it but here you all go:
<Click Image>
:o
Very cool! Independence Day was the first thing that came to mind. Keep it up!
-Laurifer
NICE WORK! 
I really like it. Here are some things you could you improve:
Make the lights in the city go off, one by one away from the explosion, rather than all at once.
When the asteroid/bomb hits the city there is instantly a ball of fire above that gets sucked in to it. Would be better if the ball started small than got bigger.
Mushroom cloud needs to be much bigger.
I really like the look of the city too. It looks pretty photo realistic. 
Fixing those few things and I’d give you a 10/10.
Nice, though the individual particles seen around the shockwave somewhat at the end spoils the anim slightly. The metoer feels somewhat small and the “straight down to earth” trajectory makes it feel less exciting than a curved path to earth.
thx for the coments but i really dont have time to mod it so…(SATs coming up :()
Its meant to be a bomb, and the reason the city looks photorealistic is because it is a photo. 
with some different glow effects to make it seem more 3d.
:-? It’s a photo?
…
Isn’t that cheating? :Z
Well nice animation anyway.
No modelling and such isnt the focus its the animation contest, it is just a back drop, the focus of voting is supposed to be on the animtation, in this case the explosion.
I like it! Nice effect - I would love to see that in animation, tracked to a video.
The only crit I have is that there are too many ‘stars’ used (for the bomb and the ‘first wave’), but maybe it’s just me ;).
Your explosion is really great. I like the explosions very much but I can’t make a good one. So could you post your *.blend file to I coult see how you did it? Thanks. It’s really amazing explosiooonnnnn.
VERY cool. I see a lot of things that could be worked on (don’t have time to list, sorry) but this is some really good stuff!
TorQ
I personally LOVE IT!..one thing…the “explosion mushroom” should be way bigger in my opinion. It looks sooo small there in the middle of all the fires/smoke/shockwave…you should make it bigger IMO…anyway good stuff!
sry double post
Wow, thx for the replies!, maybe sometime ill get the chance to rework it now SATs are over but thx everyone.
Nice, but chilling…
Arnaud
Cool! It could look even better if you added some shakiness to the camera when the shock wave hits.
I wish i could but i cant with the backround image itll move with the camera, ruining the 3d illution.