Gemini North has recently unveiled striking new images of Comet 3I/ATLAS, which has reemerged from behind the Sun as it exits our Solar System. The observations were made during a session of the community outreach program, Shadow the Scientists, enabling students and the public to engage with researchers while they use the world’s leading telescopes.
On November 26, 2025, astronomers utilized the Gemini Multi-Object Spectrograph (GMOS) at the Gemini North Observatory in Maunakea, Hawai‘i, to capture these images of the notable interstellar object. This marks the third time such an object has been identified, and the latest images illustrate significant changes in the comet’s behavior following its closest interaction with the Sun. The International Gemini Observatory, which includes Gemini North, is partly funded by the U.S. National Science Foundation (NSF) and managed by NSF NOIRLab.
After its passage near the Sun, Comet 3I/ATLAS appeared close to the triple-star system Zaniah in the constellation Virgo. These images are part of an initiative designed to engage the public in scientific endeavors. The program, led by Bryce Bolin, a research scientist from Eureka Scientific, aims to connect people with the complexities of altitude-level astronomical observations.
The newly released images were constructed from exposures taken through filters in blue, green, orange, and red wavelengths. While the comet appears to emit a greenish glow due to light from diatomic carbon gases escaping from its coma as it heats up, earlier captured images revealed a reddish hue. The change in color is attributed to alterations in the composition of the gases surrounding the comet as it progresses along its journey.
Looking ahead, scientists remain curious about how the comet will react as it distanced itself from the Sun’s heat and begins to cool. Historical observations of other comets indicate a potential time delay in their reactions to solar heating, which might lead to changes in gas release or even explosive outbursts. Continuation of the observations at Gemini will help determine the comet’s evolving gas composition and behavior.
This collaboration with Shadow the Scientists exemplifies NOIRLab’s commitment to combining scientific advancement with public engagement. By giving the public unprecedented access to live observation experiences and data collection, such initiatives not only further scientific knowledge but also ignite curiosity and inspire future generations of scientists.
Bolin emphasized the importance of these endeavors, stating, “Sharing an observing experience in some of the best conditions available gives the public a truly front-row view of our interstellar visitor. Allowing the public to see what we do as astronomers and how we do it also helps demystify the scientific and data collection process, adding transparency to our study of this fascinating object.”
The Gemini Archive makes all collected data available for public download, ensuring transparency and encouraging further exploration of these astronomical phenomena. Through efforts like these, the captivating realm of the cosmos becomes increasingly accessible and engaging for everyone.