In November of 2025, the Jupiter Icy Moons Explorer (Juice), operated by ESA, utilized five of its scientific instruments to conduct observations of 3I/ATLAS. This celestial body represents the second known interstellar comet to traverse our local interstellar medium. Furthermore, the probe successfully captured a novel visual depiction of this extraterrestrial visitor through its Navigation Camera (NavCam).
“Although the comprehensive data sets generated by the scientific instruments are scheduled for delivery to Earth in February 2026, our dedicated team felt compelled to examine preliminary findings without delay,” stated representatives of the Juice mission team.
“We elected to attempt the download of merely a quarter of a single NavCam image, eager to ascertain the nature of the forthcoming revelations.”
“The comet, remarkably conspicuous and exhibiting clear indications of energetic activity, presented us with a welcome surprise.”
“Not only is the luminous envelope of gas encircling the comet, referred to as its coma, readily apparent, but we also discerned the subtle presence of two distinct tails.”
“The comet’s ‘plasma tail,’ composed of ionized gas, extends prominently towards the upper portion of the captured frame.”
“A fainter ‘dust tail,’ fashioned from minuscule solid particulate matter, may also be discernible, appearing to trail towards the lower left sector of the image.”
The visual record of 3I/ATLAS was acquired on November 2, during the initial observation window allocated for the comet by Juice.
This capture occurred two days prior to Juice’s closest orbital proximity to the comet, an event that transpired on November 4 at an approximate separation of 66 million kilometers (41 million miles).
“We anticipate receiving the observational data from the five scientific instruments that were activated during these procedures—namely, JANUS, MAJIS, UVS, SWI, and PEP—on February 18 and 20 of 2026,” conveyed the research cohort.
“This temporal disparity in data transmission stems from Juice currently leveraging its primary high-gain antenna as a thermal shield to mitigate solar radiation, thereby necessitating the utilization of its secondary medium-gain antenna for data relay to Earth, which operates at a significantly reduced bandwidth.”
Although Juice maintained a greater distance from 3I/ATLAS compared to the proximity achieved by ESA’s Mars orbiters in October, its observation of 3I/ATLAS took place shortly after the comet’s perihelion, indicating a more heightened state of activity.
“We foresee the identification of more pronounced manifestations of this increased activity within the data streaming from the scientific payloads,” elucidated the scientific investigators.
“This projected analysis encompasses not only imagery generated by JANUS, Juice’s advanced optical imaging system, but also delves into spectral analysis data from MAJIS and UVS, compositional insights derived from SWI, and particle trajectory information furnished by PEP.”
