ESA’s ExoMars and Mars Express Observe Comet 3I/ATLAS
The two Mars orbiters had the closest view of the comet of all ESA spacecraft. During its closest approach to the Red Planet on 3 October, the interstellar interloper was 30 million km away from them. Each spacecraft used its dedicated camera to watch the comet pass. Both cameras are designed to photograph the bright […]
NASA Released The First Mars Image Of 3I/ATLAS
3I/ATLAS has been spotted passing near Mars, NASA’s Mars Perseverance rover acquired this image using its onboard Right Navigation Camera. The object appears as a massive cylindrical shape in some of the photos, leading to speculation that it could be more than just a comet. Enhanced images circulating online show the object glowing green as it moves closer […]
Interstellar Comet 3I/ATLAS Will Be Observed by Missions on Mars and Jupiter
Comet 3I/ATLAS was first spotted on 1 July 2025 by an Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile. Since then, Earth has been moving away from 3I/ATLAS as it approaches the Sun. The comet is now on the other side of the Sun, making it impossible to observe from Earth. ESA […]
Gemini South Captures Growing Tail of Interstellar Comet 3I/ATLAS
On 27 August 2025, researchers used the Gemini Multi-Object Spectrograph (GMOS) on Gemini South at Cerro Pachón in Chile to obtain deep, multi-color images of interstellar comet Comet 3I/ATLAS. Gemini South is one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab. These observations […]
The Blue Tail of Comet 3I/ATLAS
The tail of interstellar comet 3I/ATLAS is inverted, faint, and very difficult to photograph. Amateur astronomer Michael Jaeger has discovered the trick: “You have to use a blue filter,” he says. Jaeger and his colleague Gerald Rhemann obtained images of the enigmatic object on August 28. Here is one of the images: Jaeger and Rhemann […]
NASA Recently Observed the Interstellar Comet 3I/ATLAS
NASA’s James Webb Space Telescope observed interstellar comet 3I/ATLAS Aug. 6, with its Near-Infrared Spectrograph instrument. The research team has been analyzing insights from Webb’s data, and a preprint is available online. Webb is one of NASA’s space telescopes observing this comet, together providing more information about its size, physical properties, and chemical makeup. For […]
Hubble Calculates the Size of Interstellar Comet 3I/ATLAS
Hubble’s observations are allowing astronomers to more accurately estimate the size of the comet’s solid icy nucleus. The upper limit on the diameter of the nucleus is 5.6 kilometers, though it could be as small as 320 metres across, researchers report. Though the Hubble images put tighter constraints on the nucleus size compared to previous […]
Interstellar Object Comet 3I/ATLAS Detected
Using the Gemini North telescope in Hawai‘i, a team of astronomers led by Karen Meech (Institute for Astronomy/University of Hawai‘i) has captured an image of comet 3I/ATLAS, an interstellar object that was first detected on 1 July 2025 by ATLAS (Asteroid Terrestrial-impact Last Alert System). Gemini North is one half of the International Gemini Observatory, […]