Our recent discussions of active SETI, otherwise known as METI (Messaging to Extraterrestrial Intelligence), highlighted many of the key issues involved while demonstrating just how controversial the topic has become. But is there a way to look at METI experiments more objectively?
The San Marino Scale has been widely suggested as a method for assessing the risks we incur with deliberate transmissions from the Earth to other stars. Introduced by Iván Almár in 2005, the Scale is a work in progress that draws on the model of the Richter Scale, which quantifies the severity of earthquakes. The IAA SETI Permanent Study Group continues to work on it, hoping to measure “…the potential exposure of employing electromagnetic communications technology to announce Earth’s presence to our cosmic companions, or replying to a successful SETI detection.”