International SETI Launches New Detection Scale

Press Release From: SETI League
Posted: Sunday, October 20, 2002

A new scale designed to give the public an expert view of any claimed detection of extraterrestrial intelligence has been launched today by the International Academy of Astronautics' Search for Extraterrestrial Intelligence Permanent Study Group at the World Space Congress in Houston.

The Rio Scale was initiated by Drs. Ivan Almar of Hungary and Jill Tarter of the SETI Institute in California to give the media and the public an idea of the credibility and importance - as determined by a panel of SETI scientists - of any claim that intelligence elsewhere in the universe has been detected.

To demonstrate the Rio Scale, Dr. Seth Shostak of the SETI Institute and Almar have authored a paper for the World Space Congress assessing fictional and past non-fictional SETI events. From the realm of fiction they include the films  Contact,  The Arrival,  Independence Day,  The Sphere  and  2001: A Space Odyssey  and books including  The Listeners,  The Sparrow and The Coming. The non-fiction claims include the "face on Mars" and a SETI hoax involving the star EQ Peg.

So what Rio Scale rating would they get? The scale runs from zero (for non-credible claims of detection) to ten (for a completely reliable detection.) The SETI type detection in the movie Contact  gets high marks near10 because of the confirmations by telescopes around the world. On the other hand a claim of a real detection in the EQ Peg hoax reaches only 3-4 on the scale during the claim, dropping to zero when a large radio telescope proves the signal is false.

"Hollywood has been rather inventive about scenarios involving contact with extraterrestrial societies, and their stories are well known," says Shostak. "Some of these films make good 'lab rats' for testing out the Rio Scale, and testing is definitely desirable. After all, if SETI researchers picks up a signal, it will be very useful to have a scheme in place for assessing the importance and reliability of the discovery."

If you would like to try to estimate the Rio Scale for these events yourself, a website has been set up by the SETI League, which is currently hosting the IAA SETI Group's Internet presence. Browse to  and then click on "Rio Scale."

SETI scientists seek to determine through microwave and optical measurements whether humankind is alone in the universe. Since Congress terminated NASA's SETI funding in 1993, The SETI League and other scientific groups have been attempting to privatize the research. Experimenters interested in participating in the search for intelligent alien life, or citizens wishing to help support it, should email to, check the SETI League Web site at, send a fax to 1 (201) 641-1771, or contact The SETI League, Inc. membership hotline at 1 (800) TAU-SETI. Be sure to provide us with a postal address to which we will mail further information. The SETI League, Inc. is a membership-supported, non-profit [501(c)(3)], educational and scientific corporation dedicated to the electromagnetic Search for Extra-Terrestrial Intelligence.

For more information contact: Dr. H. Paul Shuch, Executive Director (201) 641-1770, or email

// end //

More news releases and status reports or top stories.

Please follow SpaceRef on Twitter and Like us on Facebook.