touchdown

Touchdown is a term used in several domains to denote the moment when a moving object makes contact with a surface. In aviation, football, and space exploration, it marks a transition between motion and rest, often carrying safety, scoring, or mission success implications.

In aviation, touchdown refers to the moment an aircraft's landing gear touches the runway, completing the landing. The exact point is influenced by approach speed, angle, weight, and runway conditions. After touchdown, pilots use braking, spoilers, reverse thrust, and throttle adjustments to decelerate and exit the runway safely.

In American football and Canadian football, a touchdown is a scoring play worth six points. It occurs when a player carries or catches the ball in the opponent's end zone or gains possession there. After scoring, teams typically attempt an extra point (kick or two-point conversion) to increase their total.

In spaceflight, touchdown denotes the moment a lander or rover makes surface contact. A successful touchdown is usually described as a soft landing, achieved with thrusters and controlled descent to nullify vertical velocity; a hard landing involves excessive impact and can damage the vehicle.

Etymology-wise, the term derives from the literal act of touching the ground. It is now used across disciplines to denote final contact with a surface, often tied to safety, scoring, or mission success.