Utilizing the European Space Agency’s (ESA) XMM-Newton observatory, celestial researchers have procured an X-ray depiction of 3I/ATLAS. This celestial body represents the third confirmed extraterrestrial entity identified traversing our Solar System, following in the wake of 1I/ʻOumuamua and 2I/Borisov.
This XMM-Newton image showcases an X-ray perspective of the interstellar comet designated 3I/ATLAS. Positioned at the focal point of the visualization, a luminous crimson spot is discernible against a somber backdrop, evoking the appearance of an incandescent marker. Emanating from this central locus, subtle gradations of violet and azure extend outwards, forming a modestly canted quadrilateral enclosure. This frame is bisected by a slender horizontal demarcation, indicative of the detector’s gap. The vermilion hue signifies radiation in the low-energy X-ray spectrum, whereas the cerulean tones denote regions of near-vacuum exhibiting minimal X-ray emissions. Attribution: ESA / XMM-Newton / C. Lisse / S. Cabot / XMM ISO Team.
On the third day of December in 2025, XMM-Newton conducted an observation of the interstellar comet 3I/ATLAS, extending for a duration of approximately 20 hours.
Throughout this observational period, the interstellar entity maintained a distance of roughly 282 to 285 million kilometers from the observational spacecraft.
The comet was scrutinized by XMM-Newton employing its European Photon Imaging Camera (EPIC)-PN instrument, which is recognized as its most sensitive X-ray detection apparatus.
“This XMM-Newton depiction portrays the comet emitting a luminescence in low-energy X-rays: blue hues indicate void areas with scarce X-ray presence, whereas the color red accentuates the comet’s X-ray radiance,” conveyed members of the XMM-Newton team in an official declaration.
The astronomical community had anticipated the detection of such a glow, predicated on the principle that gaseous molecules emanating from the comet, upon encountering the solar wind, instigate the emission of X-rays.
“These X-ray emissions can originate from the interplay between the solar wind and gaseous constituents such as water vapor, carbon dioxide, or carbon monoxide—substances previously identified by sophisticated instruments like the James Webb Space Telescope (a collaboration between NASA, ESA, and CSA) and NASA’s SPHEREx mission,” they elaborated.
“However, X-ray detection offers unparalleled sensitivity towards gases like hydrogen and nitrogen.”
“These elements are virtually imperceptible to optical and ultraviolet instrumentation, including the camera systems aboard the NASA/ESA Hubble Space Telescope or ESA’s JUICE probe.”
“Consequently, X-ray observational techniques constitute a formidable analytical instrument,” they underscored.
“They empower scientific investigators to identify and meticulously study gaseous compounds that other observational devices struggle to detect with ease.”
“A number of scientific cohorts posit that the inaugural interstellar object ever identified, 1I/‘Oumuamua, might have comprised exotic frozen volatiles such as nitrogen or hydrogen.”
“While 1I/‘Oumuamua is now beyond our observational reach, 3I/ATLAS presents a novel prospect for the detailed study of an interstellar object. Expedient X-ray observations, in conjunction with other observational strategies, will be instrumental in assisting researchers to ascertain its precise composition.”
