Interstellar comet 3I/ATLAS studied by scientists
Interstellar comet 3I/ATLAS, the third confirmed interstellar object, was discovered in July 2025 by the ATLAS survey and has been extensively studied by scientists worldwide.
The comet, also designated C/2025 N1 (ATLAS), was first spotted on July 1, 2025, at about 5 AU from the Sun, moving at around 60 km/s relative to the solar system. Pre-discovery images from telescopes like the Vera C. Rubin Observatory extended observations back to June 2025, confirming its hyperbolic trajectory from outside our solar system. It follows ‘Oumuamua (1I) and Borisov (2I) as the third such visitor.
NASA classified it as a comet due to its weak coma and outgassing, with a nucleus estimated at 5.6 km in diameter. The James Webb Space Telescope (JWST) detected unusually high carbon dioxide relative to water in its coma, along with water ice, carbon monoxide, and carbonyl sulfide, suggesting formation under intense radiation. Hubble and ground-based telescopes like Palomar and Apache Point measured dust ejection rates of 6 kg/s for small grains and 60 kg/s for larger ones in July 2025.
Studies from observatories including Kottamia and APO revealed a red surface and extended coma brighter than stars, confirming cometary activity. As it neared perihelion inside Mars’ orbit in late October 2025, spacecraft and Earth telescopes raced to analyze its jets and glow before it exits the system. Recent data as of December 2025 affirm it behaves like solar system comets, ruling out exotic theories like alien tech.
