The discovery of 3I/ATLAS, only the third confirmed interstellar object ever observed passing through our Solar System, is already reshaping how astronomers model the properties of objects arriving from beyond our cosmic neighbourhood. Despite increasing the sample size from two to three, scientists say the impact on theoretical models has been disproportionate, exposing deep flaws in long-held probability assumptions about interstellar debris.
Discovered in July 2025 by the ATLAS survey and rapidly followed up by major observatories, 3I/ATLAS has introduced physical characteristics that do not fit comfortably within existing statistical frameworks built around earlier visitors 'Oumuamua and 2I/Borisov.
