Observers from a project in Italy recorded a new image that proves the remarkable expansion of the ionic tail of the interstellar comet 3I/ATLAS. The record indicates that the object coming from outside our system is becoming more active as it approaches the Sun. The tail, now more defined and structured, offers astronomers a unique opportunity to study an interstellar visitor in depth.
The capture was carried out by the Virtual Telescope Project, at the Bellatrix Observatory, using remote robotic telescopes. The comet was spotted just 14 degrees above the eastern horizon, but its ionic tail, in bluish tones, stood out clearly, despite interference from the Moon’s light. The gaseous material is being released at an increasing rate, indicating a significant evolution in the comet’s trajectory.
Growth of the ion tail reinforces the mystery of 3I/ATLAS
The record obtained in the early hours of November 11, 2025 is the most recent in a series of observations that accompany 3I/ATLAS. The photograph combines 18 120-second exposures, allowing for stunning detail of the comet’s structure.
This rapid evolution of the ionic tail is a direct indicator of the intensity of sublimation of volatile gases and dust. The ultraviolet radiation emitted by the Sun interacts with the gas molecules released, stripping electrons and creating ions that are dragged by the solar wind. The comet, now brighter and more active, follows a pattern of behavior expected for objects rich in carbon dioxide ice ($text{CO}_2$).
- The ionic tail (bluish) always points away from the Sun, propelsgiven by the solar wind.
- The dust tail (yellowish) is more curved and follows the comet’s orbit.
- The core of 3I/ATLAS is surrounded by a compact coma, and the tail extends about 0.7 degrees into the Earth’s sky.
Visitor identification and composition
3I/ATLAS is the third interstellar object confirmed to date, joining the asteroid 1I/’Oumuamua, from 2017, and the comet 2I/Borisov, from 2019. Its luminosity is higher than that of its predecessors, which makes it easier to study by ground-based telescopes.
Its intensity of activity and the growth of its tail provide crucial clues about the star system from which it originated, as well as the composition of comets in other galactic neighborhoods.
Tracking and unusual phenomena
The scientific community maintains continuous monitoring of the object. The Virtual Telescope Project has planned a live broadcast of its observation so that the public can follow the passage of 3I/ATLAS in real time. This type of coverage is essential for documenting each stage of the comet’s journey through our system.
In a related development, astronomersdetected a radio signal coming from the comet as it passed halfway along its path. Experts quickly ruled out the possibility of technological origin, explaining that the phenomenon has entirely natural causes, linked to the intense ionization of its gases. The combination of ion tail growth and radio emission reinforces the dynamic and unique nature of 3I/ATLAS, keeping scientists mobilized to extract as much information as possible before it resumes its course into interstellar space.
