Convert Knot (UK) (kt (UK)) to Cosmic Velocity - Third (v₃) instantly.
About these units
Knot (UK) (kt (UK))
The UK knot historically varied slightly from the international knot because the UK used different values for the nautical mile depending on era and maritime authority. Though the differences were minor, they mattered in navigation, where precision affects charting, dead reckoning, and ocean voyaging. Modern UK practice fully aligns with the international knot (1 nautical mile per hour), but historical documents and charts may reference older UK knot values. The knot's rich maritime heritage—used by sailors measuring speed with knotted ropes dragged along the water—makes it one of the oldest continuously used speed units.
Cosmic Velocity - Third (v₃)
The third cosmic velocity is the speed required to escape the entire Solar System from Earth's orbit, overcoming the gravitational pull of the Sun. This speed is approximately 16.7 km/s, though missions often achieve this gradually using gravitational assists rather than brute-force acceleration. Space probes such as Voyager 1, Voyager 2, and New Horizons have exceeded v₃, making them interstellar travelers. The third cosmic velocity represents the threshold where an object ceases to be bound to the Sun and begins drifting through the galaxy—one of the most profound expansions of human technological capability.