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 […]
I Watched Scientists View the Interstellar Comet 3I/ATLAS in Real Time. Here’s What they Saw
Few cosmic visitors have captured the fascination of astronomers quite like the interstellar comet 3I/ATLAS. Hurtling through our solar system from the depths of interstellar space, this icy wanderer is only the third known object of its kind, and where it came from remains a mystery. Since its discovery on July 1, 2025, by the […]
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 […]