For the first time, astronomers have captured two distinct X-ray views of an interstellar comet, providing an unprecedented view of the interaction between a visitor from beyond our solar system and the solar wind.
Interstellar comet 3I/ATLASthe third confirmed object known to have originated outside our own solar systemIt has now been imaged in X-ray light by both the European Space Agency’s (ESA) XMM-Newton observatory and the X-ray Imaging and Spectroscopy Mission (XRISM) led by the Japanese space agency JAXA in partnership with NASA and ESA. These X-ray observations allow scientists to detect and study gases that other instruments cannot easily detect, according to a statement of the ESA.
kites They glow in visible light when sunlight reflects off dust and gas escaping from their icy core, while X-ray light tells a very different story. In space, the interaction between fast-moving charged particles from the sun, also known as solar wind – and the cloud of gas surrounding a comet produces X-ray emissions. Detecting that glow allows scientists to track where and how these interactions occur and what types of gases are present at levels that optical telescopes might miss.
While NASA James Webb Telescope and other instruments have already detected abundant water vapor, carbon monoxide and carbon dioxide in the 3I/ATLAS coma, X-ray observations are exceptionally sensitive to lighter gases such as hydrogen and nitrogen that would otherwise be difficult to detect.
The first X-ray observation of 3I/ATLAS was made by the XRISM Space Telescopewho observed the comet for 17 hours between November 26 and 28. The resulting image was captured using XRISM’s soft X-ray telescope, Xtend, whose field of view spans approximately 1.2 million square miles (3 million square kilometers), revealing a statement of ESA publishing the image.
The XRISM data also contains spectral signatures of elements such as carbon, nitrogen and oxygen, helping scientists begin to unravel the mix of particles released from the comet’s nucleus and how they interact with the nearby high-energy environment. the sunESA officials said in the statement.
Shortly after, the ESAs Newton XMM The X-ray observatory studied 3I/ATLAS for about 20 hours on December 3, when the comet was approximately 175-177 million miles (282-285 million kilometers) from the spacecraft. The image was captured using the telescope’s most sensitive X-ray instrument, the European Photon Imaging Camera (EPIC)-pn, and reveals a distinctive X-ray glow (shown in red) surrounded by fainter gradients. These features mark regions where the solar wind interacts with the gas coming out of the comet, according to a statement of ESA publishing the image.
“3I/ATLAS presents a new opportunity to study an interstellar object, and observations in X-ray light will complement other observations to help scientists discover what it is made of,” ESA officials said in the statement.
Together, the X-ray, optical, infrared and radio observations offer new insights into 3I/ATLAS as it makes its strange journey through the inner solar system, with its next closest approach to Earth It is expected around December 19.


