Interstellar Comet 3I/ATLAS Exhibits Unusual Carbon Dioxide Levels
Recent observations of interstellar comet 3I/ATLAS reveal an unexpectedly high carbon dioxide-to-water ratio, suggesting unique formation conditions.
Astronomers have observed interstellar comet 3I/ATLAS displaying an unusually high carbon dioxide (CO₂) to water (H₂O) ratio in its coma, indicating distinctive formation conditions. The James Webb Space Telescope (JWST) detected a CO₂ to H₂O ratio of approximately 8:1, one of the highest ever recorded in a comet.
This elevated CO₂ content suggests that 3I/ATLAS may have formed near the CO₂ ice line in its original protoplanetary disk or been exposed to higher radiation levels than typical solar system comets. The comet's nucleus is estimated to be between 320 meters and 5.6 kilometers in diameter.
Discovered on July 1, 2025, by the ATLAS telescope in Chile, 3I/ATLAS is the third confirmed interstellar object to enter our solar system. It is currently traveling at approximately 60 kilometers per second and will make its closest approach to the Sun in late October 2025, passing just inside the orbit of Mars.
The comet poses no threat to Earth, as it will remain at least 240 million kilometers away. Its unique characteristics provide a rare opportunity for scientists to study the composition and origins of interstellar objects.