Throughout November 2025, ESA’s Jupiter Icy Moons Explorer (Juice) used 5 of its science devices to watch 3I/ATLAS. The devices collected details about how the comet is behaving and what it’s manufactured from.
As well as, Juice snapped the comet with its onboard Navigation Digicam (NavCam), designed not as a high-resolution science digital camera, however to assist Juice navigate Jupiter’s icy moons following arrival in 2031.
Although the info from the science devices gained’t arrive on Earth till February 2026, our Juice group couldn’t wait that lengthy. They determined to strive downloading only a quarter of a single NavCam picture to see what was in retailer for them. The very clearly seen comet, surrounded by indicators of exercise, shocked them.
Not solely will we clearly see the glowing halo of fuel surrounding the comet referred to as its coma, we additionally see a touch of two tails. The comet’s ‘plasma tail’ – made up of electrically charged fuel, stretches out in direction of the highest of the body. We may have the ability to see a fainter ‘mud tail’ – made up of tiny strong particles – stretching to the decrease left of the body. Extra on the construction of a comet.
The picture was taken on 2 November 2025, throughout Juice’s first slot for observing 3I/ATLAS. It was two days earlier than Juice’s closest method to the comet, which occurred on 4 November at a distance of about 66 million km.
We anticipate to obtain the info from the 5 scientific devices switched on through the observations – JANUS, MAJIS, UVS, SWI and PEP – on 18 and 20 February 2026. The delay is as a result of Juice is at the moment utilizing its foremost high-gain antenna as a warmth defend to guard it from the Solar, leaving its smaller medium-gain antenna to ship information again to Earth at a a lot decrease charge.
Although Juice was farther from 3I/ATLAS than our Mars orbiters had been again in October, it noticed 3I/ATLAS simply after the comet’s closest method to the Solar, that means that it was in a extra energetic state. We anticipate to see clearer indicators of this exercise within the information from the science devices. This consists of not solely photographs from JANUS – Juice’s high-resolution optical digital camera – but additionally spectrometry information from MAJIS and UVS, composition information from SWI, and particle information from PEP.
For the newest updates and FAQs associated to comet 3I/ATLAS, see esa.int/3IATLAS.
Click on right here to obtain an annotated model of the picture.
[Image description: Grainy space image, with white dots on a dark background. At the centre of the image is a larger, bright white blob with a faint white line stretching towards the top of the frame.]
