Free Astronomy Magazine September-October 2025

12 SEPTEMBER-OCTOBER 2025 ASTRO PUBLISHING NSF program director for the Inter- national Gemini Observatory. “We look forward to a bounty of new data and insights as this object warms itself on sunlight before con- tinuing its cold, dark journey be- tween the stars.” These visitors from faraway regions of the cosmos are valuable objects to study since they offer a tangible by NOIRLab Josie Fenske Gemini North observes comet 3I/ATLAS U sing the Gemini North tele- scope in Hawai’i, a team of astronomers led by Karen Meech (Institute for Astronomy/Uni- versity of Hawai’i) has captured an image of comet 3I/ATLAS, an inter- stellar object that was first detected on 1 July 2025 by ATLAS (Asteroid Terrestrial-impact Last Alert System). Gemini North is one half of the In- ternational Gemini Observatory, partly funded by the U.S. National Science Foundation and operated by NSF NOIRLab. The incredible sen- sitivity of Gemini North’s Multi-Ob- ject Spectrograph (GMOS-N) reveals the comet’s compact coma — a cloud of gas and dust surrounding its icy nucleus. Interstellar objects are objects that originate outside of, and are ob- served passing through, our Solar System. Ranging from tens of me- ters to a few kilometers in size, these objects are pieces of cosmic debris leftover from the formation of their host star’s planetary sys- tems. As these remnants orbit their star, the gravity of nearby larger planets and passing nearby stars can launch them out of their home sys- tems and into interstellar space, where they can cross paths with other solar systems. “The sensitivity and scheduling agility of the International Gemini Observatory has provided critical early characterization of this inter- stellar wanderer,” says Martin Still,