Interstellar comet 3I/ATLAS, discovered in 2025, has captivated astronomers with its unique characteristics. This comet, the third of its kind ever found, has provided valuable insights into the formation history of comets that originated outside our Solar System. The study, led by Cyrielle Opitom and colleagues, utilized the European Southern Observatory's Very Large Telescope (VLT) to measure the comet's isotopic ratios, specifically carbon and nitrogen isotopes in cyanide molecules. These ratios are crucial indicators of a comet's origin, as they are highly sensitive to the physical conditions during its formation. The findings suggest that 3I/ATLAS likely formed in the outer regions around an old, low-metallicity star, indicating it may be much older than the Sun. This discovery offers a rare opportunity to study the composition of another planetary system that formed long before our Sun and Solar System existed, providing valuable insights into the early stages of planetary formation.
