Michio Kaku told NewsNation he believes interstellar comet 3I/ATLAS is likely extremely old—perhaps around 7 billion years—and that its unusual nickel-rich chemistry can be explained by long-term exposure to diverse environments. While Harvard’s Avi Loeb has suggested more exotic possibilities, Kaku urges that speculation be accompanied by quantified confidence levels. NASA reportedly has high-resolution images from Oct. 2, and 3I/ATLAS will make its closest Earth approach around Dec. 19.
Michio Kaku Says Interstellar Comet 3I/ATLAS May Be ~7 Billion Years Old — Not an Alien Vessel
Michio Kaku told NewsNation he believes interstellar comet 3I/ATLAS is likely extremely old—perhaps around 7 billion years—and that its unusual nickel-rich chemistry can be explained by long-term exposure to diverse environments. While Harvard’s Avi Loeb has suggested more exotic possibilities, Kaku urges that speculation be accompanied by quantified confidence levels. NASA reportedly has high-resolution images from Oct. 2, and 3I/ATLAS will make its closest Earth approach around Dec. 19.
12:02, 09.11.2025Science
The unusual properties of interstellar comet 3I/ATLAS are likely explained by extreme age rather than an artificial origin, theoretical physicist Michio Kaku told NewsNation. The comet’s odd chemistry and behavior have prompted debate after Harvard professor Avi Loeb highlighted anomalies such as an absent conventional tail and unusually strong nickel signatures.
Kaku, the bestselling author of Hyperspace and Quantum Supremacy, noted that many comets observed in our system have estimated ages of roughly 3 to 4 billion years. By contrast, he said 3I/ATLAS may be far older and that prolonged exposure to varied environments could account for its atypical composition.
Age, chemistry and the nickel anomaly
"This is a very old object, perhaps 7 billion years old," Kaku told NewsNation, suggesting that the comet’s elevated nickel readings and other chemical oddities reflect accumulation and alteration over a much longer timescale. In his view, age and long-term environmental processing are plausible, natural explanations for the observations.
"That’s why, for example, the nickel content of the comet is off scale. Its chemical composition is not what an ordinary comet should be, and that I think is because over 7 billion years it’s had plenty of time to accumulate different gases, different elements, different kinds of environments that it goes into. I think that explains a lot of the mystery behind the comet."
Is there an engine? Loeb’s suggestion and Kaku’s response
Loeb and others have speculated that the object’s behavior—including reports that it seemed to accelerate as it passed near the Sun—could indicate nonnatural propulsion. Kaku acknowledged the reported acceleration but urged caution: he said plausible natural explanations (for example, a fragment breaking off or asymmetric outgassing) could account for a sudden spurt in velocity.
"There could be reasons that explain why there’s a sudden spurt in velocity," Kaku said. "That’s not a smoking gun." He emphasized the need to quantify speculative claims and to report confidence levels so the public and the scientific community understand how likely an extraordinary claim is.
Data, timeline and next steps
3I/ATLAS is expected to make its closest approach to Earth around Dec. 19 before continuing out of the solar system. NASA reportedly captured high-resolution images on Oct. 2; some scientists, including Loeb, have urged the agency to release the latest data so independent researchers can analyze it. Kaku supports such a release but remains unconvinced the object is anything other than a comet shaped by long-term exposure to space environments.
Bottom line: While the object’s chemistry and behavior are unusual, Kaku favors an explanation rooted in extreme age and natural processes and warns against jumping to sensational conclusions without quantified evidence.