The interstellar comet 3I/Atlas had its tail enlarged recorded by a robotic unit of the Virtual Telescope Project, at the Bellatrix Astronomical Observatory, in Manciano, Italy, on November 11, 2025. The image, captured after perihelion, the closest point to the Sun, reveals a clearer ionic tail, stretched by 0.7 degrees in the northeast direction. The observation confirms greater activity of the comet, which did not fragment, defying scientific predictions. The live broadcast of the celestial body’s passage is scheduled for November 19.
- The comet was discovered on July 1, 2025 by the Atlas telescope in Chile.
- It is the third interstellar object identified, after Oumuamua (2017) and Borisov (2019).
- NASA ensures that 3I/Atlas poses no risk to Earth.
- ESA astronomers estimate the comet to be 7.6 billion years old.
Technology behind capture
The ARTEC250+Paramount ME+C3Pro61000EC robotic unit was essential to register the tail. Operated remotely, it overcame perihelion perspective limitations.
The Virtual Telescope Project, led by Gianluca Masi, uses robotic telescopes for global observations. The platform democratizes access to astronomy with live broadcasts.
Comet characteristics
3I/Atlas has a coma rich in carbon dioxide, unusual for comets. Studies of the James Webb Telescope apohave a high proportion of CO₂ in relation to water.
Its hyperbolic orbit confirms origins outside the Solar System. The comet travels at 210,000 km/h, heading towards interstellar space.
The ionic tail, now more visible, reflects the sublimation of ice by solar heat. The anti-tail, facing the Sun, was also observed, a rare phenomenon.
The comet’s nucleus is between 320 meters and 5.6 km in diameter, according to NASA. Hubble data indicates dust loss similar to solar comets.
Interstellar comet 3I/ATLAS (aka C/2025 N1 ATLAS): the ion tail is getting longer – 11 Nov. 2025.
— Space Initiatives (@AsteroidEnergy) November 11, 2025
by Gianluca Masi and the Virtual telescope pic.twitter.com/CfiAK5kPAv
Global Notes
Missions to Mars, such as China’s Tianwen-1, captured images of the comet from 30 million km away. ESA’s ExoMars TGO and Mars Express probes complemented the records.
The International Asteroid Warning Network (IAWN) will conduct an observation campaign until January 2026. The focus is to refine the comet’s trajectory.
Terrestrial telescopes, such as Gemini Sul, in Chile, also recorded the growth of the tail. The images show increased activity of the nucleus.
Scientific meaning
3I/Atlas is a window into distant star systems with unique chemical composition. Its passage offers rare data on the formation of interstellar comets.
Next steps
The live broadcast on YouTube, on November 19th, at 1:15 am (Brasília time), will allow viewing in real time. Amateur astronomers with modest telescopes can try to observe it at dawn, in places without light pollution.
