Mysterious X-ray emissions from interstellar object 3I/ATLAS baffle scientists

An interstellar object named 3I/ATLAS has left scientists puzzled after emitting unusual X-ray radiation. Observations by Japan’s XRISM space observatory revealed an elongated structure within its core, sparking debate about its true nature. Some researchers, including Harvard astrophysicist Avi Loeb, suggest it could even be an extraterrestrial probe. From November 26 to 28, 2025, the Japan Aerospace Exploration Agency (JAXA) studied 3I/ATLAS using the Xtend X-ray telescope aboard the XRISM observatory. Unlike previous interstellar visitors like 'Oumuamua and Comet Borisov, this object released intense X-ray emissions. Typically, comets produce X-rays when solar wind particles interact with their gases, but the radiation from 3I/ATLAS appeared far stronger and more complex.

The X-rays originated from a region within the object’s core, stretching about 5 arcminutes—or roughly 400,000 kilometres. Images from NASA’s Perseverance rover on Mars also showed 3I/ATLAS with a distinct cylindrical shape. The size of its core remains unclear, with estimates ranging from a few hundred metres to several kilometres.

Harvard’s Avi Loeb has proposed that 3I/ATLAS might be an artificial probe, pointing to the unusual X-ray patterns as potential evidence. While his theory remains speculative, scientists have not ruled it out entirely. Further analysis is still required to confirm whether the emissions truly come from cometary activity or something else. The discovery of X-ray emissions from 3I/ATLAS has raised new questions about interstellar objects. Researchers continue to investigate whether the radiation stems from natural processes or an unknown artificial source. Until more data is gathered, the true nature of 3I/ATLAS will remain uncertain.