Comet 3I/ATLAS, discovered on July 1, 2025, is only the third known interstellar visitor to the solar system, following 1I/'Oumuamua in 2017 and 2I/Borisov in 2019.
Notes on verification
Confirmed by NASA, University of Hawaii IfA, and CBC News, with consistent details on discovery date and sequence of interstellar objects. [tier=gold indep_score=0.95 clusters=3 claim_tier=notable]
Sources
- The Ten Most Significant Science Stories of 2025, From Medical ... (seed:science_and_space)
- https://science.nasa.gov/solar-system/comets/3i-atlas/3i-atlas-facts-and-faqs/ (corroboration)
- https://about.ifa.hawaii.edu/research/3i/ (corroboration)
- https://www.cbc.ca/lite/story/1.7575576 (corroboration)