Harvard’s Loeb Flags Interstellar Object 3I/ATLAS as Possible Alien Probe

Harvard astrophysicist Avi Loeb says the recently discovered interstellar object 3I/ATLAS may be an extraterrestrial reconnaissance probe, citing its rare trajectory and an unexpected glow that appears ahead of, rather than behind, the 20-kilometre-wide body. First detected in early July by the ATLAS telescope in Chile and officially classified by NASA as a comet, 3I/ATLAS is moving at more than 210,000 kilometres per hour and is only the third confirmed visitor from outside the Solar System after 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019. Loeb argues that the object’s orbit is aligned with the plane of the planets—a configuration he estimates would occur randomly only once in 500 cases—and that its planned course brings it unusually close to Mars, Venus and Jupiter, an event he puts at one-in-20,000 odds. The object is expected to reach its perihelion, about 130 million miles from the Sun, on 30 October 2025. Other astronomers remain sceptical. Planetary scientist Karen Meech of the University of Hawaiʻi’s Institute for Astronomy calls the probe hypothesis “irresponsible,” saying 3I/ATLAS behaves like a normal comet and that its path can be explained by conventional celestial mechanics. Observatories worldwide are continuing to track the body, seeking further data before it exits the Solar System.