3I/ATLAS is moving very fast through the Solar System. At discovery, it had a hyperbolic excess velocity of about 58 km/s (36 miles per second or roughly 1.02 AU per month) relative to the Sun. As it approaches the Sun, it accelerates and will reach its maximum speed at perihelion (closest approach to the Sun) of about 68 km/s (42 miles per second). This corresponds to approximately 130,000 miles per hour or 209,000 kilometers per hour, which is the highest speed recorded for a solar system visitor so far. In summary:
- Initial speed relative to Sun: ~58 km/s (36 mi/s)
- Speed at perihelion: ~68 km/s (42 mi/s)
- Speed in mph: ~130,000 mph
- Speed in km/h: ~209,000 km/h
3I/ATLAS moves faster than previous known interstellar objects like 1I/ʻOumuamua and 2I/Borisov and will escape the Solar System due to its very high velocity and hyperbolic trajectory.
