Another interstellar comet has been discovered on its way through the solar system. Officially named 3I/ATLAS, the comet was discovered on July 1, 2025 by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile.
Comet 3I/ATLAS is the third confirmed object from outside the solar system after ‘Oumuamua (and all it associated hype in 2017), and comet 2I/Borisov in 2019. The comet is arriving from the direction of the constellation Sagittarius, and will be leaving the solar system in the direction of the constellation Scorpius this fall. I was able to add the object into Stellarium, and generate an ephemeris showing the comet’s location over the next two months:
The Minor Planet Center (MPC) reports that there appears to be cometary activity, with a small coma and short tail. The MPC strongly encourages additional observations to better constrain the object’s orbit and nature.
So… when is NASA pointing the JWST at that thing? Stay tuned – this is a developing story.
Cover Image: Simulation of a small comet in the inner solar system. Credit: Bob Trembley/SpaceEngine
Related:
JPL Small Body Database Entry
NASA Discovers Interstellar Comet Moving Through Solar System
New interstellar comet 3I/ATLAS is hurtling through the solar system — and you can watch it live online today
