3I/ATLAS, from elsewhere
Discovered on 1 July 2025 by the ATLAS survey in Chile, 3I/ATLAS is the third object known to come from another star system, after ʻOumuamua (2017) and Borisov (2019). Its open orbit (e > 1) takes it through the solar system only once.
- Date
- —
- Distance from the Sun
- —
- Distance from the Earth
- —
Heliocentric trajectory from JPL Horizons (4-day steps); planets from the JPL approximate Keplerian elements. Sizes and tail illustrative.
Spotted by the ATLAS telescope at Río Hurtado (Chile) on 1 July 2025, the comet immediately showed an orbit impossible for a solar-system body: its eccentricity exceeds 6, and its speed far from the Sun, close to 58 km/s, is that of an object arriving from interstellar space.
It passed about 0.2 au from Mars in early October 2025, reached perihelion at the end of October, 1.36 au from the Sun, then moved away, passing 1.8 au from the Earth in December and close to Jupiter in March 2026. Like ʻOumuamua and Borisov before it, it will not return.
The elements and trajectory shown here are those of the latest JPL orbit solution; they are updated at each import.
| Body | Date | Minimum distance |
|---|---|---|
| Sun (perihelion) | 2025-10-29 | 1,350 au |
| Mercury | 2025-10-08 | 1,162 au (174 M km) |
| Venus | 2025-11-03 | 0,650 au (97 M km) |
| Earth | 2025-12-19 | 1,798 au (269 M km) |
| Mars | 2025-10-03 | 0,195 au (29 M km) |
| Jupiter | 2026-03-16 | 0,358 au (54 M km) |
| Eccentricity e | 6.12 ± 4.4e-05 |
| Perihelion distance q | 1.35 au ± 4.1e-06 |
| Inclination i | 175 deg ± 7.7e-05 |
| Longitude of the ascending node Ω | 323 deg ± 0.00052 |
| Argument of perihelion ω | 129 deg ± 0.00053 |
| Perihelion time (JD TDB) | 2460977.942 TDB ± 0.00018 |
| Semi-major axis a | -0.264 au ± 1.8e-06 |
| comet total magnitude slope | 7.5 |
| comet total magnitude | 11.8 |
| Solution | 55 · arc 2025-10-03 → 2026-10-16, 117 observations |
The trajectory is imported weekly from the JPL Horizons API (heliocentric vectors, ecliptic J2000) and the orbital elements daily from the JPL Small-Body Database. Distances to the planets are computed here with Standish’s approximate elements.
- Interstellar comet 3I/ATLAS (C/2025 N1): JPL orbit solution
-
NASA/JPL Small-Body Database, 3I/ATLAS (C/2025 N1), osculating orbital elements and photometric parameters.
· source page ↗
Licence : NASA/JPL, public domain (cite JPL SSD/CNEOS) · retrieved on Oct 23, 2026 · SHA-256 3f47134b36cd… - Interstellar comet 3I/ATLAS: heliocentric trajectory (JPL Horizons)
-
NASA/JPL Horizons, heliocentric ecliptic J2000 position vectors of 3I/ATLAS.
· source page ↗
Licence : NASA/JPL, public domain (cite JPL SSD/CNEOS) · retrieved on Oct 23, 2026 · SHA-256 75b09d7319a0…