Nuclear physics
Megaton (Mt)
A unit of nuclear yield equal to 1,000,000 tons (or 1,000 kilotons) of TNT equivalent.
A megaton is a unit for strategic thermonuclear weapons. Most modern strategic warheads are sub-megaton (100-500 kt) for accuracy reasons; only large city-busting weapons exceeded 1 Mt. Tsar Bomba (50 Mt) is the largest weapon ever detonated.