3I/ATLAS Comet’s Strange Water Points To A Birthplace Unlike Our Solar System
Astronomers using ALMA have measured deuterated water in interstellar comet 3I/ATLAS, finding a deuterium-to-hydrogen ratio over 40 times higher than Earth’s oceans. The result indicates the comet formed in a much colder environment than the early solar system. The data were collected just after the comet’s perihelion as it now leaves the solar system.