A bomb explodes on the moon. How long will it take for the sound to reach the earth

Sound propagation needs a medium.
E&M waves, however, can travel through vacuum.
The people on the Earth can see the flash, but no sound.

I'm pretty sure that with space being a vacuum that sound does not travel through it, the only way that you would hear something is if the explosion affected the earth or atmosphere.

Maybe if you detonated a big enough bomb, some of the material would impact the earths atmosphere and create some noise.

The sound will never reach Earth because there are not enough molecules or atoms of matter per cubic centimeter of space to create the pressure waves in a medium that is a sound wave.

It will never reach Earth. There is not medium for sound to travel from the Moon to the Earth.

Outer space have no air. Sound need air to travel. Moon explosion make no sound.

What? Speak up! There's a vacuum out here!

You just have to know the distance of moon from earth and speed of sound wave. then distance divide by speed. u would get the answer.