Alien 'Wow!' Signal Could Soon be Explained

Message boards : SETI@home Science : Alien 'Wow!' Signal Could Soon be Explained
Message board moderation

To post messages, you must log in.

1 · 2 · Next

AuthorMessage
Dr Who Fan
Volunteer tester
Avatar

Send message
Joined: 8 Jan 01
Posts: 1183
Credit: 584,438
RAC: 279
United States
Message 1780597 - Posted: 20 Apr 2016, 7:32:15 UTC

Alien 'Wow!' Signal Could Soon be Explained

The story behind the famous "Wow!" signal has an eerie quality that has inspired countless science fiction alien encounters and is often lauded as one of the strongest pieces of evidence that we are, in fact, not alone in the universe.


ID: 1780597 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3335
Credit: 1,322,163
RAC: 0
United States
Message 1780632 - Posted: 20 Apr 2016, 9:49:28 UTC - in response to Message 1780597.  

There is no evidence that the signal was anything other than a natural occurrence or a glitch in the equipment. If they had had the smarts to record the alleged message then we could have examined it for intelligence or a passing beep from a satellite.
ID: 1780632 · Report as offensive
Profile Gordon Lowe
Volunteer moderator
Avatar

Send message
Joined: 5 Nov 00
Posts: 9819
Credit: 5,175,866
RAC: 2,542
United States
Message 1780751 - Posted: 20 Apr 2016, 16:38:26 UTC

The article says radio telescope time is not available to monitor this event. It seems like a pretty important hypothesis, and worthy of rearranging the time schedules.
The mind is a weird and mysterious place
ID: 1780751 · Report as offensive
Profile LynnProject Donor
Volunteer tester
Avatar

Send message
Joined: 20 Nov 00
Posts: 11837
Credit: 32,003,088
RAC: 33,839
United States
Message 1780825 - Posted: 20 Apr 2016, 21:55:59 UTC - in response to Message 1780751.  

The signal could have come from comets.
ET Phone Home
ID: 1780825 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1780837 - Posted: 20 Apr 2016, 22:36:26 UTC - in response to Message 1780825.  

The signal could have come from comets.

Or much closer as Delaware OH is not in a radio quiet zone
ID: 1780837 · Report as offensive
Profile Somebody who doesn't support SETI anymore

Send message
Joined: 29 Apr 07
Posts: 15
Credit: 949,350
RAC: 0
Canada
Message 1780843 - Posted: 20 Apr 2016, 22:57:04 UTC - in response to Message 1780837.  
Last modified: 20 Apr 2016, 22:57:49 UTC

Or much closer as Delaware OH is not in a radio quiet zone


I think this has been ruled out, due to the fact that only one of the two feed horns detected the signal.
ID: 1780843 · Report as offensive
Profile Gordon Lowe
Volunteer moderator
Avatar

Send message
Joined: 5 Nov 00
Posts: 9819
Credit: 5,175,866
RAC: 2,542
United States
Message 1780858 - Posted: 21 Apr 2016, 0:47:17 UTC - in response to Message 1780825.  

The signal could have come from comets.


Yes, and that's exactly why this new look should be done.
The mind is a weird and mysterious place
ID: 1780858 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1780859 - Posted: 21 Apr 2016, 0:50:52 UTC - in response to Message 1780843.  

Or much closer as Delaware OH is not in a radio quiet zone


I think this has been ruled out, due to the fact that only one of the two feed horns detected the signal.

Does not rule out aircraft as source as that would pass over only one horn.
ID: 1780859 · Report as offensive
Profile Somebody who doesn't support SETI anymore

Send message
Joined: 29 Apr 07
Posts: 15
Credit: 949,350
RAC: 0
Canada
Message 1780861 - Posted: 21 Apr 2016, 1:01:20 UTC - in response to Message 1780859.  
Last modified: 21 Apr 2016, 1:01:37 UTC

Does not rule out aircraft as source as that would pass over only one horn.



The horns were only five feet apart.


Plus I found this at http://www.bigear.org/wow20th.htm#dualhorn

Aircraft

There are two major ways to rule out airplanes and other aircraft: (1) no aircraft transmitters operate in the protected radio band around 1420 MHz; and (2) aircraft move with respect to the celestial background. The Wow! source intensity pattern received matched almost perfectly the pattern expected from a small-angular-diameter (point) radio source on the "celestial sphere" (i.e., at such a large distance that there is no perceptible motion relative to the background stars). An aircraft, which would show a significant motion with respect to the stars, would also cause the received pattern of intensities to depart noticeably from that expected for a point source.

ID: 1780861 · Report as offensive
Michael Watson

Send message
Joined: 7 Feb 08
Posts: 939
Credit: 1,115,081
RAC: 1,437
Message 1780863 - Posted: 21 Apr 2016, 1:06:21 UTC
Last modified: 21 Apr 2016, 1:10:13 UTC

Also, the signal was heard for just the length of time it would take a point in distant space to pass through the one antenna beam. This tends to make local interference, and equipment artifacts seem very unlikely.

Natural phenomena are expected to occur over a relatively wide range of frequencies. The wow signal was essentially confined to a single 10 KHz wide channel.

Comets are not observed to be strong radio sources on or near the hydrogen line, where the wow signal was detected. This signal was very strong, about 30 sigma.
ID: 1780863 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1781662 - Posted: 23 Apr 2016, 14:52:36 UTC - in response to Message 1780861.  

Does not rule out aircraft as source as that would pass over only one horn.



The horns were only five feet apart.

Then any ET source would have hit both horns and only a local source could have hit one and not the other.
ID: 1781662 · Report as offensive
Michael Watson

Send message
Joined: 7 Feb 08
Posts: 939
Credit: 1,115,081
RAC: 1,437
Message 1781685 - Posted: 23 Apr 2016, 16:04:45 UTC

It seems perfectly possible that either a local radio signal or one from distant space could have passed through one beam, or both. In the former case, all that would be necessary, is for the transmitter to have been turned off before the signal reached the second beam.

If an aircraft were involved, in could also have flown in a route that happened to not intersect the second beam. The distance between the feed horns, given as five feet, is not significant. The angle in which they were pointed, and in which they directed the beams, is what is important here.

The means of ruling out an aircraft is the time it took the signal to pass through the beam. This matches the apparent motion of the stars, imparted by Earth's rotation. One would expect an aircraft to move much more quickly than this.
ID: 1781685 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3335
Credit: 1,322,163
RAC: 0
United States
Message 1781694 - Posted: 23 Apr 2016, 16:38:47 UTC - in response to Message 1781685.  

One would expect an aircraft to move much more quickly than this.


At the equator, the earth is rotating at more than 1000 miles per hour.
ID: 1781694 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1781739 - Posted: 23 Apr 2016, 18:51:53 UTC - in response to Message 1781685.  

One would expect an aircraft to move much more quickly than this.

Excepting helicopters and balloons of course.
ID: 1781739 · Report as offensive
Michael Watson

Send message
Joined: 7 Feb 08
Posts: 939
Credit: 1,115,081
RAC: 1,437
Message 1781742 - Posted: 23 Apr 2016, 19:02:13 UTC

Stars typically take about 12 hours to move across the sky, from one horizon to the other. That seems improbably slow for an airplane, helicopter, or even a balloon.
ID: 1781742 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1781805 - Posted: 23 Apr 2016, 22:37:07 UTC - in response to Message 1781742.  

Stars typically take about 12 hours to move across the sky, from one horizon to the other. That seems improbably slow for an airplane, helicopter, or even a balloon.

If the signal was from out there and the dish is pointing at out there, tracking, then it should not move period, signal is on or off no in between and one horn only. If the dish is fixed relative to the ground then the signal will look like a Gaussian curve as out there drifts past and when out there gets to the other horn you get the same Gaussian curve signal again. If the dish is tracking and the source moves like an airplane, helicopter, balloon, satellite, then the signal looks like a Gaussian. If the dish is slewing then everything looks like a Gaussian just with different time scale.

As to radio quiet, realize that the third harmonic of a very heavy use UHF band is the frequency being studied. Transmitters do produce harmonics so just because it is a "quiet" frequency does not mean it is quiet!

Finally I see they say they checked for satellites. While that rules out commercial birds, they have not been able to rule out military birds as they don't always publish those orbits and other governments may stealth their birds then change orbit to look at an interesting location at a different time than the enemy expects to try and catch something.

As it hit one horn only and it appears as if the dish was used fixed so they would get benefit of the two horns, if the signal was ET then ET wasn't way out there or it would be on both horns. That puts the signal close by, and the exact same arguments against man made source movement apply to ET's movement.
ID: 1781805 · Report as offensive
Michael Watson

Send message
Joined: 7 Feb 08
Posts: 939
Credit: 1,115,081
RAC: 1,437
Message 1781891 - Posted: 24 Apr 2016, 1:46:51 UTC
Last modified: 24 Apr 2016, 1:54:51 UTC

The antenna used to receive the 'wow signal' was not movable, nor was it a 'dish', in the usual sense. Its reception beams were allowed to sweep through the sky, using the rotation of the Earth.

The wow signal was received on 1420.4556 MHz. One third of that frequency is ~473.4852 MHz. That places it in the midst of the video signal range for television channel 14. If such a signal were detected, it would have the characteristic 4.5 MHz video bandwidth of an American television transmission. The wow signal occupied only a single 10 KHz wide channel.

The range 1420 through 1427 MHz is reserved for radio astronomy. It seems very unlikely that a military satellite, with its secret business to conduct, would have a transmitter in that frequency range. It would be making itself very conspicuous, as well as violating international agreements.

Persons more knowledgeable than I in these matters have indicated that the simplest explanation for the the wow signal appearing in the first beam, but not the second, is that it ceased before the second beam was in a position to receive it.

The length of the wow signal was about 72 seconds. It displayed a rising and falling gaussian curve over than time span. This allowed the astronomers to calculate that the signal moved through the antenna beam at the same rate as the fixed stars. An object closer to the antenna would be expected to transit the beam in substantially less time.
ID: 1781891 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3335
Credit: 1,322,163
RAC: 0
United States
Message 1781908 - Posted: 24 Apr 2016, 3:09:57 UTC

As I have repeatedly said: Since no one recorded the signal we have absolutely no reason to say that we were contacted by an intelligence that was not Earth bound.
ID: 1781908 · Report as offensive
Michael Watson

Send message
Joined: 7 Feb 08
Posts: 939
Credit: 1,115,081
RAC: 1,437
Message 1782049 - Posted: 24 Apr 2016, 14:31:49 UTC

The wow signal occurred when no one was present. A computer system transcribed the sky position, time of reception, radio frequency, duration, and strength of the signal over time, integrated into 12 second 'bins'.

If some detectable form of modulation was obscured by the integration time, this is regrettable, but it was not this limitation that made an extraterrestrial intelligence source for the signal ambiguous. The real problem was that the signal disappeared after 72 seconds, and could not be reacquired.

If the signal had continued long enough, or repeated, it could have been studied in greater detail, and possibly been confirmed by other radio astronomy facilities. The existence of a narrow band radio signal, ascertained to be from outside our solar system would make a good case for extraterrestrial intelligence, even if the detailed content was not understandable.

Given the great strength of the wow signal, 30 sigma, it seems possible that it was beamed in our direction.
ID: 1782049 · Report as offensive
Profile Gary CharpentierCrowdfunding Project Donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 21137
Credit: 30,708,271
RAC: 25,009
United States
Message 1782095 - Posted: 24 Apr 2016, 16:49:27 UTC - in response to Message 1781891.  

The antenna used to receive the 'wow signal' was not movable, nor was it a 'dish', in the usual sense. Its reception beams were allowed to sweep through the sky, using the rotation of the Earth.

The wow signal was received on 1420.4556 MHz. One third of that frequency is ~473.4852 MHz. That places it in the midst of the video signal range for television channel 14. If such a signal were detected, it would have the characteristic 4.5 MHz video bandwidth of an American television transmission. The wow signal occupied only a single 10 KHz wide channel.

That frequency 473.4852 MHz is in a shared band. If there isn't a TV station on channel 14 in the area it is used by police, fire and other mobile and fixed services. Also consider that it could be the local oscillator for the receiver mixer stage. As most radios use a 10.7 MHz intermediate frequency the receive frequency would be 462.7852 which is again in the police, fire and mobile service band along with meteorologic satellite.

The range 1420 through 1427 MHz is reserved for radio astronomy. It seems very unlikely that a military satellite, with its secret business to conduct, would have a transmitter in that frequency range. It would be making itself very conspicuous, as well as violating international agreements.
Not so fast. The locations of radio astronomy sites are well known. Just turn off your transmitter when you are above the horizon. Now no one is listening! But if you looked at a chart, you would see that the band from 1420 to 1427 MHz is allocated to satellite in addition to radio astronomy.
https://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf

Persons more knowledgeable than I in these matters have indicated that the simplest explanation for the the wow signal appearing in the first beam, but not the second, is that it ceased before the second beam was in a position to receive it.

Or the direction of travel was not in the plane of the earth's rotation so it would never cross the second horn. Or it was received off some side lobe and isn't even a sky source.

The number of possible human sources far exceeds the chances of an ET source. All of them must be positively eliminated before you can say ET.
ID: 1782095 · Report as offensive
1 · 2 · Next

Message boards : SETI@home Science : Alien 'Wow!' Signal Could Soon be Explained


 
©2017 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.