Scientists have scanned the TRAPPIST-1 star system, a promising candidate for intelligent life beyond Earth, in search of technosignatures. Although no definitive signs of alien activity were found, the study provides valuable insights into the challenges and potential of this ongoing search.
Exploring the TRAPPIST-1 System
For decades, the TRAPPIST-1 star system has been an all-star target of the search for extraterrestrial intelligence (SETI) field. Only 40 light-year away, this system possesses SEVEN Earth-size exoplanets, and three of them are in the star’s (named Trappist-1) habitable zone.
The TRAPPIST-1 system is so tightly packed that any intelligent lifeforms evolving on these worlds would have an easier time communicating with and potentially even making their way to neighboring planets compared to the vast distances between local planets in our solar system. That made TRAPPIST-1 ideal for a targeted search for technosignatures — indications of technology-driven activities— that might provide evidence for the existence of intelligent life.
Seeking Signals Across Planetary Boundaries
Using the Allen Telescope Array, a group of scientists led by Nick Tusay recorded more than 28 hours of signals coming from the TRAPPIST-1 system as two of its planets were almost directly in front of their star in (what is called a planet-planet occultation). The idea is that Earth would be in optimal position to intercept any radio broadcast which should happen during these occultations.
Of these, 11,576 were shortlisted for further filtering and 2,256 could be classed as occultation-window technosignatures. They subsequently studied these signals in depth to discern if there was any statistical evidence showing they could be of an intelligent origin.
Regrettably, the case is unpersuasive for extraterrestrial technology. Those signals were probably natural, originating from the planets (and/or stars) themselves rather than any intelligent life.
Conclusion
The search for technosignatures in the TRAPPIST-1 system may have drawn a blank, but it represents another step forward in our ceaseless quest to find indications of life elsewhere in the cosmos. The knowledge gleaned from this work will further hone prospective SETI efforts, and the ongoing investigation of exoplanetary systems such as TRAPPIST-1 continues to be an integral part of humanity’s quest for cosmic company.
