Missing technosignatures? Turbulent plasma may blur ultra-narrow signals before they leave their home star systems

A new study by researchers at the SETI Institute suggests that stellar "space weather" could make radio signals from extraterrestrial intelligence harder to detect. Stellar activity and plasma turbulence near a transmitting planet can broaden an otherwise ultra-narrow signal, spreading its power across more frequencies and making it more difficult to detect in traditional narrowband searches. The paper is published in The Astrophysical Journal.