An interstellar visitor that recently swung through our neighborhood may be one of the oldest things humanity has ever seen up close. Astronomers say the comet 3I/ATLAS, which zipped past the sun and Earth in 2025, could be as much as 12 billion years old—nearly triple the age of our solar system and "less than two billion years younger than the universe itself," per Scientific American. It's chemically unlike anything local, according to a study published Monday in Nature. Using the James Webb Space Telescope and the ALMA observatory in Chile, researchers measured its isotopes and found an extreme abundance of deuterium, or "heavy" hydrogen, in its water, suggesting it formed in conditions around -243 degrees Celsius, CBS News reports.
Lead author Martin Cordiner of NASA's Goddard Space Flight Center told AFP it "maybe" is the oldest object ever observed in the solar system, and possibly a relic from the Milky Way's "cosmic noon," when stars were forming at a breakneck pace some 10 billion years ago. The comet, only the third known interstellar visitor, is now on its way back out of the solar system for good, but astronomers expect many more interstellar passersby to be spotted once the Vera C. Rubin Observatory comes online. As study co-author Stefanie Milam tells NASA, studying interstellar comets "is a major step towards learning how common, or uncommon, the conditions for the evolution of life are in the universe."
,
uBlock 
,
and
Ghostery 
)
