3I/ATLAS, as seen by the Gemini South observatory in August 2025 (Credit: International Gemini Observatory/NOIRLab/NSF/AURA/Shadow the Scientist). ============================================================================ Physicists have detected water activity during observations of the mysterious comet 3I/ATLAS, marking the first time hydroxyl gas, a chemical signature of water, has been detected from the interstellar visitor. Using NASA’s Neil Gehrels Swift Observatory, the Auburn University team determined 3I/ATLAS is releasing water at a rate of roughly 40 kilograms per second, comparable to a fire hose running at full blast, while positioned nearly three times farther from the Sun than Earth. What makes this finding particularly remarkable is the...