I've always found it fascinating that comets were associated with disaster, and the volcano fits perfectly with this. Really wonderful job on the lava, both the hot and the cooled flows look excellent!
Awesome job on the volcano. It's rare to see the subtle "glowing" effect of lava represented so well in traditional media (I'm sure it looks better again in real life too, scans can hurt traditional paintings ) The crusting lava flowers beside the melting one also look very real. And it's interesting how comet tails do that they must be turning around the sun.