Cataloguing the journey of comet 3I/ATLAS through the solar system. Because the object comes from outside our solar system, it is just passing through – so we use all the tools at our disposal to observe it before it disappears back into the cosmic dark. A host of NASA missions are coming together to observe this interstellar object, which was first discovered in summer 2025, before it leaves forever. While the comet poses no threat to Earth, NASA’s space telescopes help support the agency's ongoing mission to find, track, and better understand solar system objects.
NASA’s STEREO (Solar Terrestrial Relations Observatory) observed interstellar comet 3I/ATLAS from Sept. 11 to Oct. 2. The STEREO mission, designed to study the Sun’s activity and its influence across the solar system, is part of a fleet of NASA spacecraft observing this comet, together providing more information about its size, physical properties, and chemical makeup. […]
The ESA (European Space Agency) and NASA Solar and Heliospheric Observatory, or SOHO, spacecraft captured a glimpse of interstellar comet 3I/ATLAS on Oct. 15–26. During this time period, the spacecraft’s Large Angle and Spectrometric Coronagraph (LASCO) instrument suite spotted the comet crossing its field of view from approximately 222 million miles (358 million kilometers) away, […]
NASA’s PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission observed interstellar comet 3I/ATLAS during its passage through the inner solar system. The mission’s ability to observe areas of the sky near the Sun allowed PUNCH to track the comet as it passed close to our star, when few other observatories could. This image was created from multiple observations taken […]
Lucy’s high-resolution, black-and-white imager, L’LORRI, captured a series of photos between Sept. 15–17, as the comet was zooming toward Mars. Lucy was 240 million miles away from 3I/ATLAS, well beyond the orbit of Mars, on its way to explore eight asteroids out of two swarms of asteroids that share an orbit with Jupiter, collectively known as the Jupiter Trojan asteroids.
