Interstellar Comet 3I/ATLAS Observed by Multiple Space Missions
NASA and ESA missions have captured new images of interstellar comet 3I/ATLAS, providing insights into its structure and activity.
NASA's Hubble Space Telescope reobserved interstellar comet 3I/ATLAS on November 30, 2025, using its Wide Field Camera 3 instrument. The image shows the comet at approximately 286 million kilometers (178 million miles) from Earth, displaying a bright coma and tail structure.
The European Space Agency's Jupiter Icy Moons Explorer (JUICE) mission also captured images of 3I/ATLAS on November 2 and November 25, 2025. Despite being en route to Jupiter and not optimized for comet observation, JUICE's Navigation Camera provided clear views of the comet's coma and dual tails. The plasma tail, composed of charged particles, extends directly away from the Sun, while the dust tail, consisting of larger particles, follows a slightly different trajectory.
NASA's Mars Reconnaissance Orbiter (MRO) observed 3I/ATLAS on October 2, 2025, from a distance of 30 million kilometers (19 million miles). The High Resolution Imaging Science Experiment (HiRISE) camera captured images showing the comet's coma as a pixelated white ball, providing valuable data on its size and activity.
Additionally, NASA's Solar Terrestrial Relations Observatory (STEREO) and Polarimeter to Unify the Corona and Heliosphere (PUNCH) missions detected 3I/ATLAS. STEREO-A tracked the comet between September 11 and October 2, 2025, using its Heliospheric Imager-1 telescope, while PUNCH observed the comet photobombing images of another comet, C/2025 R2 (SWAN), between August and October 2025.
These observations contribute to a comprehensive understanding of 3I/ATLAS's behavior and composition as it traverses the Solar System. The comet is expected to make its closest approach to Earth on December 19, 2025, at a distance of approximately 273 million kilometers (170 million miles).