Scientists from SETI and Penn State University deployed the Allen Telescope to detect the alien signal from TRAPPIST-1 for 28 hours. Using planet-to-planet occultation and enhanced scanning techniques, they identified potential signals, none of which were extraterrestrial, but the method developed holds promise for future success. The project marks the longest single target search for radio signals from TRAPPIST-1.

This artist's concept allows us to imagine what it would be like to stand on the surface of the exoplanet TRAPPIST-1f, located in the TRAPPIST-1 system in the constellation Aquarius. Image source: NASA/JPL-Caltech

Researchers from the SETI Institute and Pennsylvania State University used the Allen Telescope Array to scan the TRAPPIST-1 star system for 28 hours, searching for radio signals indicative of alien technology. This is the largest search ever conducted solely on the TRAPPIST-1 star. While no signs of extraterrestrial technology were found, the project yielded important data and pioneered a new approach to future signal searches.

"This study shows that we are getting closer to detecting radio signals similar to those we send into space," said Nick Tusay, a graduate student researcher at Penn State. "Most searches assume some kind of intent, such as beacons, because our receivers have a sensitivity limit to the lowest transmit power beyond any signal we inadvertently send out. But with better equipment, like the upcoming Square Kilometer Array (SKA), we may soon be able to detect communications between alien civilizations and their spacecraft."

Planetary occultation. Source: Zayna Sheikh

The project focuses on a phenomenon called planet-planet occultation (PPO). Planetary occultation occurs when one planet moves in front of another. If intelligent life exists in this star system, radio signals sent between planets may leak out and be detected by Earth.

Using the upgraded ATA, the team scanned a wide range of frequencies, looking for narrowband signals considered possible signs of alien technology. The research team filtered through millions of potential signals and selected approximately 11,000 candidate signals for detailed analysis. The team detected 2,264 of these signals within the predicted PPO window. However, none of these signals come from intelligent creatures.

ATA's new capabilities, including advanced software that filters signals, help the team distinguish possible alien signals from Earth-based signals. They believe that improving these methods and focusing on events such as PPOs could help increase the chances of detecting extraterrestrial signals in the future.

TRAPPIST-1 is an extraordinary star system about 41 light-years away from Earth with seven Earth-sized planets, several of which are in the star's habitable zone. The ultracool dwarf star has attracted the attention of astronomers for its possible life-sustaining conditions, making it a prime target for studying exoplanet atmospheres and the possibility of alien life. Image credit: NASA and JPL/Caltech

Dr. Sofia Sheikh, a SETI researcher at the SETI Institute, said: "This project includes the work of undergraduate students in the 2023 SETI Institute Research Experience for Undergraduates (REU) program. Students are searching for signals from human-made orbiters around Mars to check whether the system is correctly detecting the signals. This is an exciting way for students to participate in cutting-edge SETI research."

The TRAPPIST-1 system is a small, cold star about 41 light-years away from Earth. It has seven rocky planets, some of which are in the habitable zone, where conditions could allow the existence of liquid water - an essential ingredient for life as we know it. This makes TRAPPIST-1 a prime target in the search for life beyond Earth.

This illustration shows what the TRAPPIST-1 planetary system might look like, based on existing data on the planet's diameter, mass and distance from its host star. Astronomers named these planets TRAPPIST-1a, TRAPPIST-1b, etc. Source: NASA/JPL-Caltech

The team did not find any extraterrestrial signals this time, but they will continue to improve their search techniques and explore other star systems. Future searches using larger, more powerful telescopes could help scientists detect fainter signals and expand our understanding of the universe.

A paper describing this research has been accepted for publication in the Astronomical Journal and is available online as a preprint.

Compiled from/SciTechDaily