Astronomers study comet 3I/ATLAS from cold Milky Way origin
Technology
Astronomers have figured out that comet 3I/ATLAS, which swung by our solar system in 2025, probably started its journey in a cold, isolated part of the Milky Way.
As it got closer to the Sun and released water vapor, scientists jumped at the chance to study what it's made of.
Comet 3I/ATLAS deuterium suggests ancient origin
Turns out, 3I/ATLAS has super high levels of deuterium, basically "heavy" hydrogen, about 30 times more than local comets and even more than Earth's oceans.
This hints that it formed in a chilly, low-radiation zone long before our Sun existed.
As researcher Teresa Paneque-Carreno put it, this discovery shows just how many different environments exist for planet formation across our galaxy.