Returning to Earth from orbit is no easy feat. To do so, spacecraft must endure temperatures of more than 1,650°C (3,000°F) as they hit the atmosphere at 25 times the speed of sound.

That’s almost exactly Mach 1, or the speed of sound.Think about that! What you are actually seeing is thousands of people reacting reflexively the show, and what pops out is a wave moving at Mach 1.