Harvard Physicist Proposes Use of Comet 3I/ATLAS for Alien Time Capsules

A groundbreaking proposal by Harvard physicist Avi Loeb suggests a novel method for communicating with potential extraterrestrial life using the interstellar comet 3I/ATLAS. Since its discovery on July 1, 2025, this comet has spurred public interest and scientific curiosity. In a paper released on December 21, 2025, Loeb outlines how humanity could send messages, or even “time capsules,” into the cosmos by “riding” on the comet’s natural trajectory.

Loeb’s theory marks a departure from traditional methods of interstellar communication, which typically focus on constructing faster spacecraft. Instead, he advocates for utilizing the inherent speed of cosmic wanderers like 3I/ATLAS to facilitate quicker outreach to potential extraterrestrial civilizations. Currently, NASA’s Voyager 1 and Voyager 2 spacecraft are humanity’s best-known efforts at sending messages into space, carrying the Voyager Golden Records, which contain sounds, images, and messages from Earth. While Loeb appreciates these efforts, he notes that they are comparatively slow.

“Sending messages in a bottle for aliens is an unduly slow process,” Loeb stated. He emphasizes that if humanity desires to make contact with extraterrestrial life, it must explore more efficient means of communication.

The speed advantage of using interstellar comets cannot be overstated. Voyager 1, launched on September 5, 1977, travels at approximately 17 kilometres per second, requiring an estimated 28,000 years to reach the outer limits of the solar system. In contrast, 3I/ATLAS moves at a staggering 60 kilometres per second, significantly reducing the time needed to escape the solar system. Loeb calculates that a time capsule attached to an object like 3I/ATLAS could reach interstellar space in only 8,000 years, a considerable improvement compared to the 30,000 years anticipated if relying on human-made probes.

Loeb concluded that “riding 3I/ATLAS offers the benefit of reaching interstellar space by the year approximately 10,000 CE instead of the year 30,000 CE.” This radical shift in timeline underscores the potential of harnessing high-speed natural objects for cosmic communication.

Future initiatives could involve attaching a record, similar to the Golden Records, to other interstellar visitors. Alternatively, messages could be etched onto the surfaces of these comets with a high-powered laser beam, thereby creating a more permanent record of human existence. While he acknowledges the uncertainty surrounding whether such messages would ever be detected, Loeb believes the rewards of such a discovery could be groundbreaking.

“If extraterrestrial life possesses the technological capabilities to read these messages,” he remarked, “it could create a new discipline at universities called ‘Interstellar Archaeology’.”

Loeb’s proposal not only challenges conventional thinking about space exploration but also opens up exciting possibilities for humanity’s future in the cosmos. As the scientific community continues to explore the mysteries of the universe, the potential for communication with alien life remains a tantalizing frontier.