Interstellar comet likely far older than Solar System, astronomers say
Astronomers have identified an interstellar comet, 3I/ATLAS, that may be up to 12 billion years old, significantly predating our Solar System. Its unique chemical composition, including high levels of heavy water, suggests it originated in an extremely cold environment outside our galaxy.
Why it matters
The discovery provides rare insights into the composition of the early universe and objects from beyond our solar neighborhood.
The Hubble Space Telescope image of the interstellar comet 3I/ATLAS on July 21, 2025. The comet has a teardrop-shaped cocoon of dust coming off its solid, icy nucleus.
The content is purely scientific reporting based on peer-reviewed research and astronomical observations.
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