Some of the latest images of 3I/ATLAS — the third confirmed interstellar object to be detected passing through our Solar System, following 1I/ʻOumuamua and 2I/Borisov — show a complex multi-jet structure.
This image of 3I/ATLAS was captured on October 31, 2025, by Lowell Observatory astronomer Qicheng Zhang. Image credit: Qicheng Zhang / Lowell Observatory.
3I/ATLAS was discovered by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile, on July 1, 2025.
Also known as C/2025 N1 (ATLAS) and A11pl3Z, the comet arrived from the direction of the constellation Sagittarius.
Its designation as the most dynamically extreme object yet recorded is due to its hyperbolic orbit with an exceptionally high eccentricity and an extreme hyperbolic excess velocity.
3I/ATLAS reached its closest approach to the Sun — known as perihelion — on October 30, 2025.
The interstellar visitor came within 1.4 AU (astronomical units) or 210 million km of the star — just inside the orbit of Mars.
At this point, the comet was traveling at its maximum speed of about 68 km/s and was briefly hidden from Earth-based telescopes due to its proximity to the Sun in the sky.
Following the perihelion, it became visible to the telescopes again and will be observable through December as it moves away from the Sun and Earth, heading back into interstellar space.
The first optical post-perihelion image of 3I/ATLAS (see above) was captured on October 31 by Lowell Observatory astronomer Qicheng Zhang using the Discovery Telescope.
This image of 3I/ATLAS was captured on November 8, 2025, by astronomers from the ICQ Comet Observations group. Image credit: M. Jäger / G. Rhemann / E. Prosperi.
On November 8, a trio of astronomers from the ICQ Comet Observations group observed the comet at 29 degrees separation from the Sun in the sky.
Their images showed a complex jet structure of at least seven jets, some of which are anti-tails.
“Given that a large number of jets appear in many directions, the reported non-gravitational acceleration of 3I/ATLAS requires much more than 10-20% of its initial mass to have been ejected near perihelion,” Harvard University’s Professor Avi Loeb said about the ICQ images.
“Only a fraction of that mass carries an excess momentum in a preferred direction.”
“This means that the cloud of debris around 3I/ATLAS must represent a substantial fraction of its initial mass for a natural comet.”
This image of 3I/ATLAS was captured on November 9, 2025, by astronomers from the British Astronomical Association. Image credit: Michael Buechner / Frank Niebling.
On November 9, a duo of astronomers from the British Astronomical Association (BAA) observed the comet using two telescopes.
Their composite images showed a long ‘smoking’ tail and two anti-tail jets.
“This multi-jet structure constitutes a remarkable target for future observations with the Hubble and Webb telescopes, as 3I/ATLAS will arrive at closest approach to Earth on December 19, 2025,” Professor Loeb said about the BAA images.
“Its minimal distance from Earth will be 269 million km, about a hundred times larger than the extent of the jet structure in the images.”
