If there is a large-scale explosion on the Moon, in how long will earthlings see it? And how long before they hear it?
Answer from: Nikolai Sosnov:
Editor-in-Chief of the literary magazine Poket-Book...
So, if the explosion happens on the visible part of the moon, we will see it in 1.28 seconds (the distance to the moon is ~384,000km:the speed of light is ~300,000km:s). And we will not hear the sound, because the space is very rarefied, and the sound is the vibrations of particles, which are very rare in space)