SETI tests new alien-hunting strategy, but TRAPPIST-1 planets remain silent

The latest hunt for alien signals in the TRAPPIST-1 planetary system has test-driven a new strategy that will allow astronomers to perform a more efficient, targeted search for technological extraterrestrial life in the future.

TRAPPIST-1 is a multi-planet system about 40.7 light-years away. Its seven rocky worlds, some of which lie in the habitable zone — the zone around a star where it isn't too hot nor too cold for a planet to host liquid water — are all bunched up so tightly that they transit their star every few days. The number of planets and their relative proximity to us make the TRAPPIST-1 system a tantalizing target for the search for extraterrestrial intelligence (SETI).

Although this latest search — in which the Allen Telescope Array of radio telescopes in California spent 28 hours in total listening to TRAPPIST-1 — did not detect any alien signals, "the point of the study was to demonstrate a more efficient search strategy, utilizing the natural orbital configuration of an edge-on multi-planet system to our advantage," Nicholas Tusay, a graduate student at Penn State University, told Space.com.