Rio de Janeiro: Rio Scale proposed for ET contact
Astronomers Iván Almár and Jill Tarter introduced the Rio Scale at a SETI meeting in Rio de Janeiro to measure the significance of potential extraterrestrial detections on a 0-10 scale. It assesses societal impact and was later updated to cover messages and artifacts.
Background
Background
The astronomers Iván Almár and Jill Tarter proposed a method of quantifying the significance of indications of extraterrestrial intelligence during the 29th SETI review meeting at the 51st International Astronautical Congress in Rio de Janeiro, Brazil, from October 2 to 6, 2000. The scale, named after the location, runs from 0 to 10 and rates how strongly a public announcement might affect society, in the manner of the Torino scale for asteroids.
Development and Formula
The rating is the product of Q (consequence potential, the sum of the class of phenomenon, the type of discovery, and the distance) and δ (credibility). High values indicate substantial impact; even false reports can have consequences. The International Academy of Astronautics adopted the scale officially in 2002.
Updates
In 2011 it was extended to distinguish between interstellar messages and physical artefacts such as technosignatures. In 2018 version 2.0 followed, with refined criteria against false reports.