The disappearance of a tail — a typically predictable feature of comets heated by solar radiation — stunned researchers. But now, only weeks later, the comet’s activity has surged.
31/ATLAS Grows a New Tail
“Exploiting the unusual good weather of this season, we imaged the interstellar comet again, recording a much more developed ion tail,” said Gianluca Masi, founder of the Virtual Telescope Project.
“Looking at the picture, we see how the ion tail of 3I/ATLAS is clearly showing better and better.”
An ion tail forms when the Sun’s ultraviolet radiation strips electrons from gases emitted by the comet. These charged particles are swept directly away from the Sun by the solar wind, creating a long, straight, bluish tail distinct from a dust tail.
The new image shows:
- A bright core and compact coma
- A sharply defined ion tail stretching roughly 0.7 degrees
- A faint anti-tail extending in the opposite direction
This renewed activity suggests increased sublimation of carbon dioxide and dust, hinting at the comet’s unique composition.
Why 31/ATLAS Matters
3I/ATLAS is only the third confirmed interstellar object, following 1I/‘Oumuamua (2017) and 2I/Borisov (2019).
