Interstellar comet 31/ATLAS: NASA tracks fastest object to enter solar system

NASA is tracking an object that is entering the solar system at approximately 245,000 km/h. This interstellar visitor is 3I/ATLAS, also known as “Comet C/2025 N1 (ATLAS) and initially dubbed A11pl3Z.

It is the third confirmed interstellar object ever detected, following ‘Oumuamua and 2I/Borisov. It has been classified as an interstellar comet due to observations showing tentative signs of a coma and tail.

3I/ATLAS is travelling at an extremely high speed, around 245,000km/h (or 152,000 mph) at its fastest approach, making it one of the fastest objects ever recorded in our solar system.

Its path is hyperbolic, meaning it is not gravitationally bound to the Sun and is just passing through before exiting the solar system.

The object was first detected in June 2025 by NASA’s ATLAS (Asteroid Terrestrial-impact Last Alert System) survey.

It is expected to reach its closest point to the Sun (perihelion) around October 30, 2025, coming just inside the orbit of Mars.

NASA has confirmed that 3I/ATLAS poses no threat to Earth. It will remain at a safe distance as it passes through.

The object presents a rare and exciting opportunity for astronomers to study material originating from another star system, providing clues about the chemistry and conditions of distant stellar neighbourhoods.

Some unusual properties, like its apparent size and trajectory near other planets, have led to speculation about an artificial origin, but the evidence points to it being a natural, though unusual, comet.