interstellar object
3I/ATLAS
The third known interstellar object, an active comet discovered in 2025 racing through the Solar System on a hyperbolic path.
- Distance from Earth today
- 1.87 billion km12.53 AU · light: 1 h 44 min
- Distance from the Sun today
- 1.94 billion km12.98 AU
- As of
- 4 November 2026position from NASA/JPL orbital elements
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Perihelion
- 1.352 AU
- Orbital period
- none – open (hyperbolic) orbit
- Orbital eccentricity
- 6.123
- Orbital inclination
- 175.2°
- Perihelion passage
- 29 October 2025
- Minimum orbit distance from Earth’s orbit (MOID)
- 0.362 AU (54.09 million km)
Source of the figures: JPL Small-Body Database (public domain).
Discovery: 2025 – ATLAS survey (Río Hurtado, Chile)
Description
3I/ATLAS was discovered on 1 July 2025 by a telescope of the ATLAS survey in Chile and was quickly recognised as only the third object known to have entered the Solar System from interstellar space. It is an active comet, moving faster than either of its predecessors, and passed closest to the Sun in late October 2025, inside the orbit of Mars. Because it passed relatively close to Mars, spacecraft orbiting that planet were able to observe it, along with space telescopes and several probes elsewhere in the Solar System. Studies of its gas and dust offer a rare sample of material formed around another star.