Search for alien transmissions in promising star system draws a blank

A search for aliens communicating between planets in one of the most promising systems to look for life has come up empty.

Discovered in 2017, TRAPPIST-1 is a system of seven Earth-sized planets orbiting a red dwarf star much dimmer than our sun, about 40 light years away. The planets all orbit closer than Mercury does to our sun and pass in front of their star from our point of view. Three of the planets orbit in the star’s habitable zone, where liquid water can exist, and they…