Could We Detect Aliens Exploding Things on Earth?

The US and Russia are both monitoring the atmosphere in high altitude planes to try to detect whether the other side is cheating on the test ban treaty. We're also basically looking for these explosions, right? Like if you can have satellites, maybe with cameras trained at the earth looking waiting for these flashes of light. Gamma rays tend to be more ionizing, so they do end up getting absorbed, but it depends a lot on the depth. But what about the question of aliens exploding things in their planets? Could we detect alien explosions or an alien nuclear war?