During a dedicated celestial observation period conducted earlier this month, the Transiting Exoplanet Survey Satellite (TESS), operated by NASA, captured the faint luminescence and trailing appendage of an interstellar comet. These recent readings, combined with existing archival data, offer potential insights into this infrequent celestial wanderer originating from beyond our Solar System.
This image of 3I/ATLAS was captured by NASA’s TESS satellite on January 15, 2026. Image credit: NASA / Daniel Muthukrishna, MIT.
The comet designated 3I/ATLAS was initially detected by the ATLAS survey telescope, a NASA-supported instrument located in Rio Hurtado, Chile, on July 1, 2025.
This celestial body, also recognized by the designations C/2025 N1 (ATLAS) and A11pl3Z, traversed into our Solar System from the celestial expanse in the direction of the constellation Sagittarius.
Its orbital trajectory represents the most dynamically extreme path ever documented within the confines of our Solar System.
The comet 3I/ATLAS achieved its closest proximity to the Sun, a point known as perihelion, on October 30, 2025.
This extraterrestrial visitor passed within a distance of 1.4 astronomical units (AU), equivalent to 210 million kilometers, of our star, positioning it just inside the orbital circumference of Mars.
Following its transit behind the Sun, the comet reappeared in the night sky in proximity to Zaniah, a multi-star system situated within the constellation Virgo.
“The TESS spacecraft systematically surveys extensive regions of the cosmos for approximately one month at a time, meticulously examining minute fluctuations in the light emitted by distant stars. This methodology is primarily employed to identify exoplanets, or celestial bodies orbiting stars beyond our Solar System,” stated astronomer Daniel Muthukrishna of MIT, along with his research associates, in a formal declaration.
“This observational approach also equips TESS with the capability to detect and track comets and asteroids across considerable distances.”
“The survey’s expansive field of view fortuitously enabled it to capture imagery of 3I/ATLAS in May 2025, a period nearly two months prior to its formal discovery.”
From January 15 through January 22, 2026, TESS re-engaged in observational duties, focusing on the interstellar comet during a specialized data acquisition campaign.
The apparent magnitude of the object was approximately 11.5, indicating an intensity roughly one hundred times dimmer than that perceivable by the human eye without optical aid.
All data collected by TESS is made accessible to the public through the Mikulski Archive for Space Telescopes.
“By scrutinizing the historical TESS datasets, we were successful in identifying the faint comet through the aggregation of multiple observation records to meticulously map its trajectory,” the astronomers reported.
