An unusual interstellar visitor speeding through our solar system was recently spotted by the powerful eye of NASA’s James Webb Space Telescope (JWST).
The American space agency revealed this week that its premier space observatory had captured new images of the comet, known as 3I/ATLAS, on August 6, 2025, using its Near-Infrared Spectrograph instrument.
Since that time, NASA researchers have been studying data collected about the object during Webb’s observations, with the latest insights appearing in a new preprint paper. The latest observations provide further confirmation that 3I/ATLAS is producing a large carbon dioxide-rich cloud of material around the object, commonly referred to as its coma.
Carbon Dioxide in Abundance
The unusual carbon dioxide abundance, previously detected in observations by NASA’s SPHEREx mission, is accompanied by traces of water, carbon monoxide, sulfur compounds, water ice, and an abundance of dust, according to the new findings made possible by Webb.
In the new paper by co-author Martin Cordiner and colleagues, 3I/ATLAS’s unusual ratio of carbon dioxide to water vapor is also noted as having been one of the highest ever measured in a comet. This is significant, as it suggests that 3I/ATLAS is quite distinct from the types of comets that originate within our Solar System.
Hellbound and Down 