ESA Juice Mission Observes Interstellar Comet 3I/ATLAS

The European Space Agency's (ESA) Jupiter Icy Moons Explorer (Juice) mission has successfully observed interstellar comet 3I/ATLAS. This marks a significant opportunity to study a celestial body from outside our Solar System.

First Glimpse: JANUS Captures Comet's Dynamics

Juice's science camera, JANUS, captured striking images of the comet. These images display dust and gas spewing from 3I/ATLAS, surrounded by a bright halo known as the coma. A long tail, with hints of rays, jets, streams, and filaments, was also visible.

The comet's behavior aligns with that expected from a typical comet, despite originating from outside the Solar System.

The JANUS camera took a notable image on November 6, 2025, precisely seven days after the comet's closest approach to the Sun. At the time of this crucial observation, Juice was approximately 66 million kilometers from the comet.

Multi-Instrument Approach to Unraveling 3I/ATLAS

Throughout November, Juice employed five of its advanced science instruments to gather extensive data on 3I/ATLAS. The instruments deployed were JANUS, MAJIS, SWI, PEP, and UVS.

This suite of instruments collected diverse information. The data is intended to reveal the comet's intricate behavior and detailed composition.

Overcoming Transmission Challenges, Analysis Begins

Data transmission to Earth faced a temporary delay. This was due to Juice's position on the opposite side of the Sun, requiring it to use its main antenna as a heat shield and a smaller antenna for slower data rates.

Instrument teams have recently received the collected data and are now deeply engaged in its analysis. JANUS alone collected over 120 images, spanning a wide wavelength range.

Teams for MAJIS, UVS, SWI, and PEP are focusing on analyzing spectrometry, composition, and particle data, respectively. All teams, including those working on Juice's navigation camera data, are scheduled to discuss their initial findings in late March.