TL;DR : SETI scientists say 3I/ATLAS is most likely a natural comet, not an alien probe. Harvard's Avi Loeb suggested a 30-40% chance it could be artificial due to some unusual features, but SETI and NASA say the evidence supports a natural origin. More observations are planned to confirm.
🔍 What Happened
- Object Discovery: On July 1, 2025, the ATLAS system detected 3I/ATLAS, the third known interstellar object after ʻOumuamua (2017) and 2I/Borisov (2019).
- Harvard Claim: Avi Loeb (Harvard astronomer) published a paper suggesting a 30-40% chance that 3I/ATLAS may be artificial, citing seven anomalies, including its alignment with the ecliptic, high speed (58 km/s), and chemical composition (nickel without iron).
- Alien Theory Details: Loeb and co-authors speculated the object could be a probe with hostile intent, citing a potential reverse Solar Oberth maneuver and the "Dark Forest" hypothesis.
🛰️ SETI and NASA's Response
- SETI Paper (Oct 9, 2025): SETI-affiliated scientist A.K.M. Eahsanul Haque published a preprint titled "Natural Origins of 3I/ATLAS: Why 3I/ATLAS is Not an Alien Probe", directly addressing Loeb’s claims.
- Natural Explanation: Haque explained the anomalies as naturally plausible, including:
- Ecliptic alignment: rare, but possible due to galactic dynamics.
- Nickel detection: consistent with natural comet processes.
- No signs of artificial propulsion or acceleration.
- SETI's Estimate: The paper estimates less than 1% probability of artificial origin, opposing Loeb’s 30-40% claim.
- NASA Statement (Sep 15, 2025): “3I/ATLAS is a comet... no evidence of artificial origin.”
đź” Current Data and Future Observations
- Observed Behavior: 3I/ATLAS shows comet-like features, including a coma and tail, and lacks non-gravitational acceleration, unlike ʻOumuamua.
- Confirmed Natural Composition: Detected substances include water ice, COâ‚‚, cyanide gas, and nickel vapor, with no radio signals found.
- Upcoming Missions:
- ESA’s Juice and NASA’s Juno plan to observe the object.
- Perihelion (closest to Sun): October 30, 2025.
- Jupiter flyby: Expected March 2026.
🧑‍🚀 Quotes from Scientists
- Avi Loeb (Harvard): “As of now, I assign a 30-40% likelihood that 3I/ATLAS does not have a fully natural origin... a technological object masquerading as a natural comet.”
- Tom Statler (NASA): “It looks like a comet. It does comet things... the evidence is overwhelmingly pointing to this object being a natural body.”
🌍 Public Reaction and Context
- Social Media Buzz: Viral claims about aliens and “dark forest attacks” gained traction on X (formerly Twitter), but many were flagged as unverified or satire.
- SETI’s Position: While debate is welcome, SETI emphasizes the need for evidence-based analysis and ongoing observation before making conclusions.