Rare interstellar comet 3I/ATLAS: What we know so far
A super-rare interstellar comet called 3I/ATLAS was spotted by the NASA-funded ATLAS telescope in Chile on July 1, 2025.
It's only the third visitor from outside our solar system ever found, after 'Oumuamua and 2I/Borisov.
The comet is zooming in from the direction of Sagittarius and isn't bound to our Sun.
When and where to spot 3I/ATLAS
3I/ATLAS was approximately 670 million kilometers from the Sun when it was discovered.
Its closest approach will be on October 30, just inside Mars's orbit—still a safe 240 million kilometers away from Earth, so there's no risk to us.
How to see the comet
You can catch a glimpse of this cosmic traveler through a regular telescope until September, before sunlight makes it too hard to spot.
It'll reappear in early December once it moves out from behind the Sun—no fancy gear needed beyond a telescope.
A glimpse into its past
Racing at about 60km per second, this comet gives scientists a rare chance to study something that formed far beyond our solar system.
Its journey has even been traced back to mid-June using earlier images!