Sonic boom

The loud shock wave heard on the ground when an aircraft flies faster than the speed of sound.

• Above Mach 1 the aircraft outruns its own pressure waves, which merge into shock waves at the nose and tail.
• The shocks form a cone behind the aircraft that sweeps the ground continuously along the whole supersonic route, not just once.
• The US banned civil supersonic flight over land in 1973, confining Concorde to ocean routes; a 2025 executive order told the FAA to lift it.
• NASA's X-59 is shaped to soften the boom to a thump; Boom Supersonic flies near Mach 1.1–1.3 so the boom bends upward before reaching the ground.