We have a new picture of interstellar comet 3I/ATLAS courtesy of the European Space Agency (ESA). Captured by the XMM-Newton space observatory, the comet was photographed on December 3 when it was about 282–285 million kilometres away.
ESA’s XMM-Newton observatory was launched in 1999 to study X-ray sources such as galactic centres, stars and black holes from an elliptical Earth orbit.
Our @ESA_XMM has observed comet #3IATLAS in X-ray light!
When gas molecules streaming from a comet collide with the solar wind they produce X-rays, seen here as the red glow of 3I/ATLAS 👉 https://t.co/Hv0Dv3AAg9
Blue marks empty space with little X-rays, while the black… pic.twitter.com/oblPMYz64Q
— ESA Science (@esascience) December 12, 2025
Comet 3I/ATLAS in X-ray
The XMM spacecraft observed the comet for around 20 hours using the European Photon Imaging Camera (EPIC), its most sensitive X-ray instrument. The comet is visible as a glowing, fuzzy red dot that is extending into the empty space which is in blue. ESA says X-rays are being produced as the gas molecules streaming from the comet are colliding with the solar wind.
Scientists have already detected water vapour, carbon dioxide, or carbon monoxide on 3I/ATLAS using the SPHEREx and James Webb Space Telescope. However, gases like hydrogen and nitrogen are almost invisible to optical and ultraviolet instruments, such as the cameras on the Hubble Space Telescope or the Jupiter-bound JUICE spacecraft. With cameras such as those on XMM-Newton, scientists can study gases otherwise hard to spot.
Recently, ESA also shared a preview of JUICE’s observation ahead of the full data release in February 2026.
“Several groups of scientists think that the first detected interstellar object, 1I/’Oumuamua (found in 2017), may have been made of exotic ice like nitrogen or hydrogen,” ESA said in a statement. “While 1I/’Oumuamua is too far away now, 3I/ATLAS presents a new opportunity to study an interstellar object, and observations in X-ray light will complement other observations to help scientists figure out what it is made of.”
Is Comet 3I/ATLAS alien tech?
Comet 3I/ATLAS is the third confirmed interstellar object to visit our solar system. Currently on an outbound trajectory, it will be closest to Earth on December 19 – around 270 million kilometres. The comet was discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) on July 1, and has been a subject of intense debate due to its strange features such as lack of tail and unusually high amount of nickel. Harvard physicist Avi Loeb even pointed out its non-gravitational acceleration suggesting it may be powered by an extraterrestrial propulsion system.
However, NASA has clarified that it is just a comet. During a press conference last month, the agency officials released pictures of the comet captured by various spacecraft and emphasised that it has a natural origin. Scientists hope to get a better look at the comet during its closest approach with Earth and settle the debate once and for all.
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