The European Space Agency's JUICE mission has just unveiled exciting new findings about the interstellar comet 3I/ATLAS, which is stirring up interest in the scientific community. In a thrilling development that occurred in November 2025, this comet re-emerged from behind the Sun and began its journey toward the far reaches of our Solar System. This event was significant because the comet exhibited heightened activity following its closest encounter with the Sun, making it once again visible to both telescopes and automated space missions.
One such mission, the JUpiter Icy Moon Explorer, or JUICE, captured an intriguing image of 3I/ATLAS using its Navigation Camera (NavCam). This photograph was taken on November 2, 2025, just two days prior to JUICE’s nearest approach to the comet, which was around 66 million kilometers (or 41 million miles) away at that time. Although this distance was greater than that of the ESA’s Mars Express and ExoMars Trace Gas Orbiter, which had previously observed the comet in October, the images from JUICE offered a glimpse of 3I/ATLAS in a more active state.
While the complete set of data from the probe's observations won’t reach Earth until February 2026, the team managed to download a quarter of the NavCam image, providing an alluring preview of what’s to come. Interestingly, the NavCam wasn’t specifically designed for high-resolution imaging, yet the results surprised the scientific team. The image not only showcased the bright coma surrounding the comet but also revealed two distinctive tails: the plasma tail and the dust tail. The plasma tail, extending upward from the coma, consists of electrically charged gas, whereas the dust tail, which extends downward, is made up of solid particles released during the comet's outgassing process.
In addition to capturing the image, JUICE utilized five of its scientific instruments to gather data regarding the composition and behavior of 3I/ATLAS, confirming its classification as a comet.
An annotated image of 3I/ATLAS, along with a map (inset), indicating its position as observed by JUICE. Image credit goes to ESA/Juice/NavCam.
The ESA expects to receive comprehensive data from its instruments between February 18th and 20th. This delay arises because JUICE is using its primary high-gain antenna as a heat shield, compelling the probe to communicate with Earth through its smaller, medium-gain antenna at a considerably slower data transmission rate. The information gathered from these instruments is anticipated to deliver a clearer understanding of the comet's active state and will include images from JANUS, the probe’s high-resolution optical camera, as well as spectrometry data from the Moons and Jupiter Imaging Spectrometer (MAJIS) and the UV imaging spectrograph (UVS).
Moreover, additional insights into the comet’s composition will be obtained through the Sub-millimeter Wave Instrument (SWI), while the Particle Environment Package (PEP) will provide data on particles surrounding the comet. Together, these findings will enable scientists to investigate the origins of the comet and explore the conditions present in other regions of our galaxy. Considering that 3I/ATLAS may be as old as 7 billion years, the data could offer invaluable insights into the history of our galaxy, predating the formation of Earth and the Solar System itself.
