“While 3I/ATLAS is most likely a comet of natural origin, we should remain open to alternative explanations,” Loeb wrote in a Medium essay. His comments echo his earlier work on the interstellar object ‘Oumuamua, which he suggested might have been artificial.
Public fascination has fueled theories that 31/ATLAS could be alien technology or a probe exploring our solar system. However, most astronomers maintain it is a cometary body—though an unusually massive and resilient one.
Timeline of Key Events
- Sep 20: Astronomers spot a mysterious green glow around 3I/ATLAS, likely from rare gases.
- Sep 23: New theory suggests it could be a “planet-forming seed.”
- Sep 25: Loeb notes the comet shows no non-gravitational acceleration, suggesting great mass—or propulsion.
- Sep 28: The comet passes through the region of the 1977 Wow! Signal.
- Sep 29: Survives a solar storm intact.
- Sep 30: Slips behind the Sun, disappearing from view.
- Oct 1–7: NASA’s Mars orbiters and ESA’s ExoMars capture its glow and detect water vapor.
- Oct 19: Keck Observatory spots a rare anti-tail pointing toward the Sun.
- Oct 21: Loeb speculates the object could use the Oberth effect to alter its trajectory unseen.
- Oct 30: Reaches perihelion at 130 million miles from the Sun.
What Comes Next after Perihelion for 31/ATLAS?
A fleet of telescopes—including NASA’s Hubble Space Telescope and ESA’s Mars Express—has been tracking the object closely. Estimates suggest its nucleus measures between 1,000 feet and 3.5 miles wide.
