Joined: 25 Nov 05
'Strong signal' stirs interest in hunt for alien life
A "strong signal" detected by a radio telescope in Russia that is scanning the heavens for signs of extraterrestrial life has stirred interest among the scientific community.
The signal is from the direction of a HD 164595, a star about 95 light-years from Earth.
The star is known to have at least one planet, and may have more.
Nick Suntzeff, a Texas A&M University astronomer told the online magazine Ars Technica that the 11 gigahertz signal was observed in part of the radio spectrum used by the military.
"If this were a real astronomical source, it would be rather strange," Mr Suntzeff was quoted as saying.
"God knows who or what broadcasts at 11Ghz, and it would not be out of the question that some sort of bursting communication is done between ground stations and satellites.
"I would follow it if I were the astronomers, but I would also not hype the fact that it may be at SETI signal given the significant chance it could be something military."
ID: 71954 ·
Help desk expert
Joined: 29 Aug 05
From Eric Korpela
Dr. Korpela wrote:
I'm sure that many of you have seen the news reports of a "SETI signal" detected from the star HD 164595
I was one of the many people who received the the email with the subject "Candidate SETI SIGNAL DETECTED by Russians from star HD 164595 by virtue of RATAN-600 radio telescope." Since the email did come from known SETI researchers, I looked over the presentation. I was unimpressed. In one out of 39 scans that passed over star showed a signal at about 4.5 times the mean noise power with a profile somewhat like the beam profile. Of course SETI@home has seen millions of potential signals with similar characteristics, but it takes more than that to make a good candidate. Multiple detections are a minimum criterion.
Because the receivers used were making broad band measurements, there's really nothing about this "signal" that would distinguish it from a natural radio transient (stellar flare, active galactic nucleus, microlensing of a background source, etc.) There's also nothing that could distinguish it from a satellite passing through the telescope field of view. All in all, it's relatively uninteresting from a SETI standpoint.
But, of course, it's been announced to the media. Reporters won't have the background to know it's not interesting. Because the media has it, and since this business runs on media, everyone will look at it. ATA is looking at it. I assume Breakthrough will look at it. Someone will look at it with Arecibo, and we'll be along for the ride. And I'll check the SETI@home database around that position. And we'll all find nothing. It's not our first time at this rodeo, so we know how it works.
Dr. Korpela wrote:
We believe a signal when
*It is persistent. It appears at the same spot in the sky in multiple observations.
*It only comes from one spot in the sky.
*If we reobserve the target, the signal is still there.
Things that add to believability
*Its frequency/period/delay does not correspond to known interference.
*Its Doppler Drift rate indicates that it is exactly frequency stable in the frame of the center of mass of the solar system
*Its properties (bandwidth, chirp rate, encoding) indicate intelligent origin.
Unfortunately the observing method used by the Russian team does not permit many of these things to be determine. 1. The signal was not persistent. 2. The signal was gone when the target was reobserved. 3. The signal frequency/period/delay cannot be determined. 4. The signal Doppler drift rate is unknown. 5. Many sources of interference, including satellites, are present in the observing band.
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ID: 71956 ·