A groundbreaking proposal from Harvard physicist Avi Loeb suggests using the interstellar comet 3I/ATLAS as a vehicle to send messages or “time capsules” to potential extraterrestrial life. This innovative idea emerged in a paper published on December 21, 2025, following the comet’s discovery on July 1, 2025. Loeb argues that harnessing these cosmic wanderers could significantly enhance humanity’s ability to communicate beyond our solar system.
Loeb’s theory challenges the conventional approach of developing faster spacecraft. Instead, he advocates for using the natural high-speed trajectories of comets like 3I/ATLAS. These interstellar objects travel at speeds that far exceed those of human-made probes. For instance, while Voyager 1, launched on September 5, 1977, moves at approximately 17 kilometres per second, 3I/ATLAS travels at about 60 kilometres per second. This speed difference means that a time capsule attached to a comet could reach interstellar space in just 8,000 years, a dramatic reduction compared to the 30,000 years projected for current spacecraft.
Loeb emphasizes the potential of interstellar comets as “natural messengers” capable of bridging the vast distances between stars. He likens the current efforts to communicate with extraterrestrial beings, such as those involving NASA’s Voyager 1 and Voyager 2, to sending a “message in a bottle.” While the Voyager missions carry Golden Records filled with sounds, images, and messages from Earth, Loeb believes this method is inefficient for establishing contact.
In his paper, Loeb writes, “If we are impatient in establishing physical contact with extraterrestrials, we can attempt to do better in reaching our cosmic neighbours with technological artefacts.” By utilizing the natural speed of comets, humanity could potentially reach out to other forms of life in a more timely manner.
The implications of Loeb’s idea extend beyond mere communication. He proposes that future missions could either attach records similar to those of the Voyager probes or even inscribe messages directly onto the surface of these comets using advanced laser technology. This approach would serve as a more permanent marker of human existence, potentially leading to what Loeb describes as a new academic field dubbed “Interstellar Archaeology.”
While the uncertainty surrounding whether these messages would ever be discovered remains, the potential benefits are significant. If advanced extraterrestrial civilizations have the capability to decipher these messages, it could lead to profound advancements in our understanding of life beyond Earth.
Loeb’s proposal invites both excitement and skepticism within the scientific community. By reimagining how humanity could engage with the cosmos, he highlights the need for innovative thinking in the quest for extraterrestrial contact. As comets like 3I/ATLAS continue their journeys through space, opportunities for groundbreaking communication efforts may lie ahead, promising new horizons for human exploration and understanding of the universe.
