NASA says interstellar object 3I/ATLAS is a comet, not an alien spacecraft, despite speculation by Avi Loeb.
NASA has rejected speculation that the interstellar object 3I/ATLAS is an alien spacecraft sent to the Solar System, following claims by Harvard astrophysicist Avi Loeb.
The comet, discovered on July 1, 2025, is traveling at nearly twice the speed of previous visitors like ‘Oumuamua and Comet Borisov and is estimated to have a nucleus of 5.6 kilometers.
Loeb suggested in a paper and blog posts that the object could be an alien probe, even citing the “Dark Forest” hypothesis that civilizations may destroy others to protect themselves.
He wrote, “3I/ATLAS achieves perihelion on the opposite side of the Sun relative to Earth. This could be intentional to avoid detailed observations.” He further speculated that if it lacked a tail, it could have been “sent towards the inner solar system by design.”
NASA, however, maintains that the object shows all natural cometary behavior. “It looks like a comet. It does comet things,” said Tom Statler, NASA’s lead scientist for Solar System small bodies. “The evidence is overwhelmingly pointing to this object being a natural body. It’s a comet.”