system
Given the following post, respond as if you're commenting on Reddit:
human
Why would a large enough asteroid explode when it hits Earth?

I can't comprehend why a hot rock hitting into essentially another rock would cause Hiroshima or larger style explosions.
gpt
Perhaps you are only considering chemical (nuclear or otherwise) releases of energy here. That is how the vast majority of human created explosions are made.

However any explosion is simply the release of a lot of energy of ANY type in a small amount of time. In this case the huge kinetic energy of the rock is been released in the small amount of time when it hits the planet.

I believe some more modern weapons are kinetic. They contain no explosive payload. Just enough mass and velocity to destroy the target.