The caption in question begins: "No one knows for sure what caused this signal. There is a slight possibility that it just might originate from an extraterrestrial intelligence."
"In fact," responds Shuch, "we have known exactly what caused this detection, ever since we posted it, along with a full explanation, to the 'What We've Heard So Far' page of our own website on 24 March 1999. We'd like it to be ET calling home. Unfortunately, the actual explanation is somewhat more mundane."
The signal in question was detected by SETI League member Gerald Cavan, on an amateur radio telescope at his home in Ontario, Canada. Cavan, a longtime amateur radio operator (callsign VE3EYR) is one of over 100 SETI League members around the world to operate his own radio telescope, as part of The SETI League's global Project Argus network. The original image (only part of which was posted as the NASA Astronomy Picture of the Day) appears online at http://www.setileague.org/photos/hits/cavan.jpg. It is but one of dozens of signals a year analyzed by SETI League members since Project Argus went online on 21 April 1996. So far, not one of these detections has passed muster as a true manifestation of extraterrestrial intelligence. "But we are not discouraged," explains Shuch. "Before we can hope to detect messages from ET, we have to learn how to identify traces of mankind's own technology."
A technical description of the signal, provided by Cavan at the time of detection, and posted to The SETI League's website along with the original image, reads as follows: "The bottom is a hit first detected by SETIFOX on 1420.477 MHz, and repeated every day at the same RA 9:36:40 DEC 3:33:52 from this location EN92ux. The interesting thing about this hit is the fact that it displays none of the modulation I normally get from GPS qrm and that the doppler is reversed. The top of the display is the GPS signal as received on 1575.4 MHz usb, after about one minute of this I switch back to the hit at 1420.477 to analyze the signal. The GPS signal gets up to S9+ on the R-7000 for the same time as the hit approx. 18 minutes, at this time the display goes back to just noise. I think the hit is caused by the strong GPS signal beating with some local signal (intermodulation)."
Subsequent collaborative analysis by multiple Project Argus participants confirmed Cavan's explanation. The SETI League publishes standardized detection and verification protocols, which specify the procedures to be followed in the event of a signal detection, in order to ensure scientific integrety and credibility.
SETI scientists use a variety of scientific approaches to determine 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 join_at_setileague_dot_org, check the SETI League Web site at http://www.setileague.org/, 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 systematic Search for Extra-Terrestrial Intelligence.
P.S. Tearsheets are always appreciated. Thank you.
entire website copyright © The SETI League, Inc.
this page last updated 11 March 2004
Top of Page