Astronomers use ALMA data to trace 3I/ATLAS predating our Sun
Astronomers have traced the origins of 3I/ATLAS, a rare interstellar comet spotted in July 2025, to an ancient and incredibly cold part of the galaxy, way before our Sun even existed.
Using data from Chile's ALMA observatory, researchers found unusual chemical signatures in this comet, and separate models and studies estimate that it is between seven and 12 billion years old, making it a true time capsule from an early stage in the galaxy's history.
High deuterium found in 3I/ATLAS water
What really sets 3I/ATLAS apart? Its water contains over 40 times more deuterium than Earth's oceans, a sign it formed in freezing clouds below minus 240 Celsius.
As lead author and doctoral candidate in the department of astronomy at the University of Michigan Luis Eduardo Salazar Manzano put it, interstellar objects are "time capsules" and the measurements help scientists "peek at the physical conditions where these objects originated."