Convert Kilometer/Second (km/s) to Cosmic Velocity - Second (v₂) instantly.
About these units
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.
Cosmic Velocity - Second (v₂)
The second cosmic velocity is the escape velocity, the speed required to completely overcome a planet's gravitational attraction without further propulsion. For Earth, this speed is about 11.2 km/s. It is higher than v₁ because escaping gravity requires exceeding orbital balance entirely, not merely achieving stable free fall. Escape velocity underlies missions to the Moon, other planets, and deep space probes. Reaching v₂ allows spacecraft to travel along trajectories that leave Earth's gravitational well permanently unless acted on by external forces. This value symbolizes humanity's ability to break free from its home world—a critical milestone in exploration.