Convert Cosmic Velocity - Third (v₃) to Kilometer/Second (km/s) instantly.
About these 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.
Kilometer/Second (km/s)
A kilometer per second represents a very high speed—1,000 meters every second—and is particularly important in astronomy, planetary science, and astrophysics. Orbital velocities around planets, escape velocities, solar winds, and the motion of stars relative to each other are commonly measured in km/s. This scale captures speeds far beyond terrestrial transportation. For example, Earth orbits the Sun at roughly 30 km/s, and meteoroids entering Earth's atmosphere may arrive at speeds between 11 and 72 km/s. km/s is a natural step up from m/s when describing the motion of celestial bodies.