3I/ATLAS: where the interstellar visitor is now
For a few months in 2025, an object from another star system swept through the inner solar system. It's still out there, and it's leaving for good. Here's where 3I/ATLAS is now and what we learned while it was close.
Where it is now
3I/ATLAS crossed the orbit of Saturn in early July 2026. It won't reach the orbit of Uranus until around April 2027, and Neptune's orbit about a year after that. In late April 2026 it was about a billion kilometers from the Sun, or 6.7 times the Earth–Sun distance. At its outbound speed of roughly 58 km/s, it has traveled several hundred million kilometers since, putting it somewhere around 13 times the Earth–Sun distance today, close to 2 billion kilometers out.
It's far too faint for backyard telescopes now. It sits in the direction of the constellation Virgo, and only the largest telescopes, Hubble among them, can still pick it out as a fuzzy dot.
What it is
- Only the third known interstellar object. After 1I/'Oumuamua in 2017 and 2I/Borisov in 2019. Its path is hyperbolic, which means the Sun's gravity can't hold it; it came from outside and it won't return.
- Discovered July 1, 2025 by the ATLAS survey telescope in Río Hurtado, Chile.
- Possibly older than the Sun. Studies estimate its age at roughly 3 to 14 billion years, depending on the model. The Solar System is about 4.6 billion years old.
- Fast. It peaked at about 68 km/s when it passed closest to the Sun on October 29, 2025.
What we learned
It became one of the most-watched comets ever. The James Webb Space Telescope detected methane and saw its gas output change after its closest pass by the Sun. The European Space Agency reported it releasing water vapor equal to about 70 Olympic swimming pools a day, with a gas and dust tail stretching around 5 million kilometers. Spacecraft orbiting Mars helped pin down its path, and it passed about 54 million kilometers from Jupiter on March 16, 2026.
Is it alien technology?
Harvard astronomer Avi Loeb has argued 3I/ATLAS has unusual features worth watching for signs of technology, and that view drew a lot of attention online. Most astronomers, and NASA and ESA, treat it as a natural comet: it has a coma and tail, it outgasses water, carbon dioxide and methane like other comets, and its light curve has shown no evidence of artificial light. The data supports a comet, an extraordinary one, since it's a sample of another star system passing through ours.
Curious how real UAP cases compare? Browse the official military footage in the Evidence Room, or check the UAP timeline.
Sources: Wikipedia: 3I/ATLAS, BBC Sky at Night, Avi Loeb, April 2026, ESA, NASA.