Astronomers Use New Technique to Search for Alien Signals Between Planets

Written by Copernical Team Thursday, 17 October 2024 21:22

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University Park PA (SPX) Oct 17, 2024

A new search technique has allowed astronomers to target exoplanets that align with Earth and each other in search of radio signals that could indicate interplanetary communication. Penn State researchers, in collaboration with the SETI Institute, recently conducted a 28-hour search of the TRAPPIST-1 system using the Allen Telescope Array (ATA), marking the most extensive investigation of its ki

Astronomers Use New Technique to Search for Alien Signals Between Planets
by Sam Sholtis for Penn News
University Park PA (SPX) Oct 17, 2024

A new search technique has allowed astronomers to target exoplanets that align with Earth and each other in search of radio signals that could indicate interplanetary communication. Penn State researchers, in collaboration with the SETI Institute, recently conducted a 28-hour search of the TRAPPIST-1 system using the Allen Telescope Array (ATA), marking the most extensive investigation of its kind for this star system. Although the search did not uncover any signs of extraterrestrial technology, the project introduced an innovative approach that could enhance future efforts to detect such signals.

"This research shows that we are getting closer to technology and methods that could detect radio signals similar to the ones we send into space," said Nick Tusay, a Penn State graduate research fellow and the study's lead author. "Most searches assume a powerful signal, like a beacon intended to reach distant planets, because our receivers have a sensitivity limit to a minimum transmitter power beyond anything we unintentionally send out. But, with better equipment, like the upcoming Square Kilometer Array, we might soon be able to detect signals from an alien civilization communicating with its spacecraft."

The team focused on planet-planet occultations (PPOs), where one planet passes in front of another from Earth's vantage point. If intelligent life were transmitting between planets in such alignments, any signal leakage could potentially be detected from Earth.

Using the enhanced capabilities of the ATA - a series of radio antennas located at the Hat Creek Observatory in California - the researchers scanned a broad range of frequencies for narrowband signals, which are often considered possible indicators of alien technology. Out of millions of potential signals detected, approximately 11,000 candidates were examined more closely, including 2,264 signals that occurred during predicted PPOs. However, all were determined to be of human origin.

The ATA's recent upgrades, including advanced signal-filtering software, allowed researchers to more effectively distinguish between potential extraterrestrial signals and Earth-based interference. The team believes that refining these methods and targeting specific events such as PPOs could significantly improve the chances of discovering alien signals in the future.

"This project included work by undergraduate students in the 2023 SETI Institute Research Experience for Undergraduates program," said Sofia Sheikh, a researcher at the SETI Institute who previously earned her Ph.D. at Penn State. "The students looked for signals from human-made orbiters around Mars to check if the system could detect signals correctly. It was an exciting way to involve students in cutting-edge SETI research."

TRAPPIST-1, located about 41 light years away, is a cool, small star hosting seven rocky planets, some of which reside within the habitable zone where conditions might allow for liquid water. This proximity and detailed knowledge of its planetary orbits make it an ideal location for testing signal detection techniques.

"The TRAPPIST-1 system is relatively close to Earth, and we have detailed information about the orbit of its planets, making it an excellent natural laboratory to test these techniques," Tusay said. "The methods and algorithms that we developed for this project can eventually be applied to other star systems and increase our chances of finding regular communications among planets beyond our solar system, if they exist."

The research did not find any extraterrestrial signals this time, but the team plans to continue refining their techniques and searching other star systems. Upcoming observations with more advanced telescopes could help detect weaker signals and broaden our knowledge of the cosmos.

The study was conducted by a team that included researchers from Penn State, the University of California, and the SETI Institute, with funding from the U.S. National Science Foundation, the Penn State Extraterrestrial Intelligence Center, and the Penn State Center for Exoplanets and Habitable Worlds.

Research Report:A Radio Technosignature Search of TRAPPIST-1 with the Allen Telescope Array