The interstellar comet 3I/ATLAS, discovered on July 1, 2025, has captured the imagination of scientists and enthusiasts alike. A bold new proposal from Avi Loeb, a physicist at Harvard University, suggests using such comets to send time capsules containing messages from humanity to potential extraterrestrial life. His groundbreaking paper, published on December 21, 2025, reconsiders traditional methods of interstellar communication.
Loeb’s theory moves away from the conventional approach of designing faster spacecraft. Instead, it advocates for leveraging the natural high-speed trajectories of comets like 3I/ATLAS for more efficient outreach. While current efforts, such as NASA’s Voyager 1 and Voyager 2 missions, involve sending messages via human-made probes, Loeb believes that interstellar comets can serve as more effective messengers.
He highlighted the limitations of the Voyager missions, which each carry the Voyager Golden Records. These records encapsulate sounds, images, music, and messages from Earth, intended to communicate our existence to any intelligent life that may encounter them. However, Loeb referred to this as a “message in a bottle,” pointing out its sluggish pace.
The speed of these interstellar comets vastly outstrips that of human-made spacecraft. Launched on September 5, 1977, Voyager 1 travels at approximately 17 kilometers per second. At this rate, it will take around 28,000 years to reach the edge of the solar system. In contrast, 3I/ATLAS is moving at about 60 kilometers per second. This significant velocity would enable a time capsule to enter interstellar space within approximately 8,000 years, drastically reducing the time required for cosmic communication.
Loeb’s calculations suggest that utilizing a comet like 3I/ATLAS could lead to reaching interstellar space by the year 10,000 CE, rather than by 30,000 CE, which would be the case if we relied solely on traditional spacecraft. He believes this time difference underscores the potential of harnessing natural cosmic travelers for interstellar messaging.
In his proposal, Loeb outlined two primary methods for sending messages. First, he suggested attaching a record similar to the Voyager Golden Records to future interstellar visitors. Alternatively, he proposed the use of high-power laser beams to engrave messages onto the surfaces of these comets. This approach could create a more permanent record of human existence.
While acknowledging the uncertainty surrounding whether these messages would ever be discovered, Loeb emphasized the profound implications of such a possibility. Should extraterrestrial civilizations possess the technology to interpret these messages, it could pave the way for a new academic field he termed “Interstellar Archaeology.”
Loeb’s innovative ideas challenge existing paradigms in the search for extraterrestrial intelligence. By thinking outside the traditional framework, he advocates for a new era of exploration that embraces the potential of our cosmic neighbors. As we continue to discover and explore the universe, the prospect of sending humanity’s story into the stars becomes increasingly compelling.
