Infrared observations from NASA’s Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) have revealed the presence of organic molecules, including those associated with pre-biological chemistry, being released by the interstellar comet 3I/ATLAS as it departs the solar system. The data, captured in December 2025, indicate the comet is emitting compounds such as methanol, hydrogen cyanide, and methane.
Discovered on July 1, 2025, by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Chile, 3I/ATLAS is only the third interstellar object ever detected. The comet’s trajectory took it within approximately 290 million miles (470 million kilometers) of the Sun in late October 2025, triggering the release of gas and dust that forms its coma – the expansive, gaseous atmosphere surrounding the comet’s nucleus. SPHEREx observed this coma during the period of December 8-12, 2025, as the object moved away from the Sun.
SPHEREx’s unique capability to observe the sky in 102 colors of infrared light allowed scientists to identify the chemical signatures within the coma. The telescope detected dust, water, organic molecules, and carbon dioxide, according to a NASA statement released February 4, 2026. The abundance of carbon dioxide extends at least 348,000 kilometers from the comet’s nucleus.
While these molecules are not life themselves, they are considered fundamental chemical ingredients in processes that could lead to the formation of biological structures under suitable conditions. The detection of these compounds suggests that complex organic matter may be common in environments beyond our solar system, originating from star systems billions of years ancient.
“These observations offer a rare window into the chemical composition of an object that likely formed around another star,” said researchers at NASA’s Jet Propulsion Laboratory. The SPHEREx dataset is freely available to scientists and the public, and further observations by other NASA missions are planned to further analyze the comet’s composition.
The mission, managed by NASA’s Jet Propulsion Laboratory, was built by BAE Systems. Data analysis is being conducted by a team of scientists at 13 institutions across the U.S., South Korea, and Taiwan, led by Jamie Bock of Caltech and Olivier Dore of JPL. Data processing and archiving are managed by IPAC at Caltech.