Kilometer per Second to Cosmic Velocity - Third

Kilometer per second measures how many kilometers an object travels in one second. Used for very high-speed phenomena like spacecraft, asteroids, and planetary motion.

1 km/s = 1,000 m/s = 3,600 km/h. There are 1,000 meters in a kilometer.

To m/s: × 1,000. To km/h: × 3,600. To mph: × 2,237.

Earth's orbital speed: 29.78 km/s. Moon's orbital speed: 1.02 km/s. Space shuttle orbital speed: 7.8 km/s. Meteor entry: 11–72 km/s.

Solar system escape velocity: 42 km/s. Voyager 1 speed: 17 km/s. Fastest star (S4714 near black hole): 24,000 km/s (8% light speed).

Underestimating the scale — 1 km/s is 3,600 km/h, extremely fast. Confusing with m/s (1000× smaller).

Think of km/s as 'space speeds.' Earth orbits at ~30 km/s. To escape Earth: 11.2 km/s. Moon orbit: ~1 km/s.

The third cosmic velocity is approximately 16,700 m/s (16.7 km/s), the minimum speed to escape the Sun's gravity from Earth's orbital position.

v₃ = √(v_sun² - v_Earth²) where v_sun is solar escape velocity from Earth's orbit. Approximately 16.7 km/s relative to Earth.

To km/h: × 3,600. To mph: × 37,282. 16.7 km/s = 60,120 km/h = 37,344 mph.

Voyager missions, future interstellar probes, and calculations for leaving the solar system.

Voyager 1: ~17 km/s relative to Sun (achieved via Jupiter gravity assist). Parker Solar Probe: 163 km/s peak (but toward Sun, not away).

Thinking Voyager was launched at 16.7 km/s — it used gravity assists. Also, confusing with speed needed to escape from Sun's surface (618 km/s).

~17 km/s to leave the solar system from Earth's orbit. Voyagers achieved this with gravity assists from planets.