'3I/ATLAS': Third interstellar object discovered after 'Oumuamua (2017) and Borisov (2019)
Say hello to 3I/ATLAS, the third-ever interstellar object spotted passing through our Solar System.
Discovered by the ATLAS telescope in Chile before October 2025, this comet is just stopping by—it's not bound to the Sun and won't be coming back.
Closest approach to the Sun on October 30
On October 30, it'll swing closest to the Sun (just inside Mars's orbit) but will stay a safe 170 million miles from Earth.
Scientists found atomic nickel vapor around it—pretty rare for such distant comets—and later detected cyanogen gas, which is more typical of comets from our own neighborhood.
A peek at the unknown
3I/ATLAS is shaking up what we thought we knew about comet chemistry and origins.
By studying it with telescopes on Earth and in space (like Hubble and James Webb), researchers are getting a rare peek at materials from outside our Solar System.
Why track distant comets?
Even though you can't see it without pro gear, tracking 3I/ATLAS helps astronomers practice spotting and predicting the paths of mysterious objects that might one day come closer—making us better prepared for whatever else space might send our way.