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

A mysterious interstellar object named 3I/ATLAS has left scientists baffled after emitting unusual X-ray radiation. Observations by JAXA’s XRISM space observatory in late November 2025 revealed an elongated, complex structure unlike anything seen before in similar visitors.

The findings have reignited debate about the object’s true nature, with some experts refusing to rule out more extraordinary explanations. Between November 26 and 28, 2025, JAXA’s XRISM observatory detected X-ray emissions from 3I/ATLAS—something never observed in previous interstellar objects like 'Oumuamua or Comet Borisov. The radiation spans roughly 5 arcminutes, equivalent to 400,000 kilometres, forming an irregular, stretched shape.

Typically, comets emit X-rays when solar wind particles interact with their gases. However, the intensity and composition of 3I/ATLAS’s emissions, likely linked to carbon, nitrogen, and oxygen, do not fit standard cometary behaviour. The source of the X-rays appears hidden within a dense gas cloud at the object’s core.

Images from NASA’s Perseverance rover on Mars also show 3I/ATLAS as cylindrical, adding to its unusual profile. Harvard astrophysicist Avi Loeb has argued that the object’s characteristics align with the possibility of an extraterrestrial probe. While his hypothesis remains unproven, scientists have not yet dismissed it outright.

Further analysis is required to determine whether the X-rays truly originate from cometary processes—or something else entirely. The discovery of X-ray emissions from 3I/ATLAS presents a puzzle that current scientific models struggle to explain. Until more data is gathered, the object’s origins and nature will remain uncertain.

Researchers continue to study the findings, leaving open the question of whether this interstellar visitor is natural—or something far more extraordinary.