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Super-intelligent aliens could easily disguise their intergalactic spacecraft to mimic natural space phenomena - almost but not quite. Astronomers and scientists have performed theoretical actobatics to normalise the strange behaviour of our recent intergalactic visitors; 1I/'Oumuamua in 2017, followed by 2I/Borisov in 2019 and the highly anomalous 3I/ATLAS in 2025.The detection and subsequent analysis of interstellar objects (ISOs) traversing the inner Solar System has precipitated a quiet crisis within the planetary science community. For centuries, the astronomical paradigm has been predicated on a clear dichotomy: the Solar System is populated by indigenous bodies—asteroids and comets—whose dynamical histories are bound to the Sun, and the interstellar medium is a void, traversed only by gas, dust, and cosmic rays. The arrival of 1I/'Oumuamua in 2017, followed by 2I/Borisov in 2019 and the highly anomalous 3I/ATLAS in 2025, has shattered this isolationist framework.
By Nathan McGrathSuper-intelligent aliens could easily disguise their intergalactic spacecraft to mimic natural space phenomena - almost but not quite. Astronomers and scientists have performed theoretical actobatics to normalise the strange behaviour of our recent intergalactic visitors; 1I/'Oumuamua in 2017, followed by 2I/Borisov in 2019 and the highly anomalous 3I/ATLAS in 2025.The detection and subsequent analysis of interstellar objects (ISOs) traversing the inner Solar System has precipitated a quiet crisis within the planetary science community. For centuries, the astronomical paradigm has been predicated on a clear dichotomy: the Solar System is populated by indigenous bodies—asteroids and comets—whose dynamical histories are bound to the Sun, and the interstellar medium is a void, traversed only by gas, dust, and cosmic rays. The arrival of 1I/'Oumuamua in 2017, followed by 2I/Borisov in 2019 and the highly anomalous 3I/ATLAS in 2025, has shattered this isolationist framework.