The Sun Comes Out Again

It sounded like an air compressor shooting small bursts of air in random directions. There was not out in the sky, nothing like in front of the sun that could have blocked it or anything like that. A bullet would have hissed or popped or cracked. It wasn't a aircraft. Helicopters don't make that noise. The fact that the whole sky went dark and the command didn't witness it 15 kilometers away, was confusing to me.