On November 26, 2025, astronomers utilized the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North Telescope located on Mauna Kea, Hawaii, to capture images of the interstellar comet 3I/ATLAS. Recent observations demonstrate how this comet has evolved since its closest approach to the Sun.
This image, taken with GMOS on the Gemini North Telescope, depicts 3I/ATLAS traveling among stars and galaxies. Operating as part of the International Gemini Observatory, it is funded in part by NSF and managed by NSF’s NOIRLab. Image credit: International Gemini Observatory / NOIRLab / NSF / AURA / B. Bolin / J. Miller & M. Rodriguez, International Gemini Observatory & NSF’s NOIRLab / TA Rector, University of Alaska Anchorage & NSF’s NOIRLab / M. Zamani, NSF’s NOIRLab.
3I/ATLAS reached its closest approach to the Sun, termed perihelion, on October 30, 2025.
Having emerged from behind the Sun, this interstellar body was observed near Zania, a triple star system situated in the Virgo constellation.
On November 26, 2025, researcher Bryce Bolin from Eureka Scientific, along with colleagues, obtained new images of the comet as part of a public outreach initiative by NSF NOIRLab in partnership with Shadow the Scientist.
“Providing the public with a viewing experience under optimal conditions allows for a genuine front-row glimpse of interstellar visitors,” Dr. Bolin stated.
“Offering the public insight into our work as astronomers and our methodologies also serves to demystify science and the data collection process, enhancing transparency in the study of this captivating astronomical entity.”
The 3I/ATLAS image, captured using GMOS, highlights the comet’s coma—a cloud of gas and dust that forms around its icy center when approaching the Sun. Image credit: International Gemini Observatory / NOIRLab / NSF / AURA / B. Bolin / J. Miller & M. Rodriguez, International Gemini Observatory & NSF’s NOIRLab / TA Rector, University of Alaska Anchorage & NSF’s NOIRLab / M. Zamani, NSF’s NOIRLab.
The recent GMOS image comprises exposures taken through four different filters: blue, green, orange, and red.
“During the exposure, the comet remains stationary in the center of the telescope’s field of view,” the astronomers explained.
“However, the background stars shift in relation to the comet, creating colorful streaks in the final image.”
“Initial images of the comet from the Shadow the Scientist session at Gemini South, Chile, exhibited a red hue.”
“In contrast, the new images released today display a subtle greenish glow.”
“This phenomenon results from light emitted by gases in the comet’s coma containing diatomic carbon, a reactive molecule made of two carbon atoms that emits light at green wavelengths. This gas evaporates as the comet heats up.”
“What remains uncertain is how comets behave as they move away from the Sun and cool down.”
“Many comets respond slowly to the Sun’s heat, as it takes time for the warmth to penetrate the comet’s interior.”
“Such delays could accelerate the evaporation of new compounds or potentially lead to the comet’s disintegration.”
Source: www.sci.news
