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Sunday, February 27, 2011

Alien Signal Detected?

A remarkable radio emission from a close by galaxy cough on June 2010 may be the indication of an alien civilization astrophysicists have been looking for.

when astrophysicists started monitoring a stellar explosion in a galaxy near our own Milky Way, they suddenly got way more than they expected. An unknown object in the same galaxy, M82, started to send out radio waves - and they are unlike anything previously recorded. 'We don't know what it is,' said co-discoverer Tom Muxlow, of the Jodrell Bank Centre for Astrophysics in Cheshire.

Muxlow and his colleagues were using Britain's MERLIN network of radio telescopes when the 'bright spot' of radio emission suddenly emerged. Muxlow explained that the source has hardly changed in brightness over the course of a year, and its spectrum is steady – very unlike the usual sources of such emissions, super novae. His best guess is that the radio source is some kind of super-dense object like a black hole or 'micro quasar' but if so it is quite unlike anything recorded before. Could it there for be artificial?If so, not everyone will be thrilled. In Paranormal News in issue 46, we reported how a scientist speaking at the Royal Society Conference on extraterrestrial life in April warned that we should expect any visiting aliens to be hostile.

Professor Conway Morris said: ETs could be disturbingly like us, and that might not be a good thing... we don't have a great track record. 'Now über-boffin Stephen Hawking has spoken out in agreement. He told the Sunday Times: 'We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet. I imagine they might exist in massive ships, having used up all there sources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach.

'If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the American Indians. 'Sci-fi fan Hawking, who has guest starred in Star Trek: The Next Generation(as well as several Simpsons episodes), says that in a universe with 100 billion galaxies he has little doubt intelligent aliens exist somewhere in the universe. 'To my mathematical brain, the numbers alone make thinking about aliens perfectly rational,' he said.

Professors Hawking and Morris will therefore be delighted to know that, according to scientists on the SETI program, the Earth is getting harder to spot. Apparently we have digital and cable television to thank for this: there are far fewer analog broadcasts and this has greatly reduced the number and power of radio waves leaking into space. In addition, mobile phone signals are so extensive that they are probably indistinguishable from noise. Even military radar signals are now bounced around in a confusing manner to stop enemy powers jamming them. 'Our improving technology is causing the Earth to become less visible,' said SETI's Frank Drake. But because his job is trying to find other civilizations out there in the cosmos, Professor Drake isn't happy about this. 'If we are the model for the universe, that is bad news,' he said.

The SETI Program

Monitoring the heavens for artificial extraterrestrial broadcasts is a daunting task—akin to looking for a needle in a haystack. Where should we look? What frequencies should we monitor? How strong will the signal be? Will it be continuous or intermittent?Will it drift? Will it change frequency? Will it even be recognizable to us? To say the least, radio frequency searches are time- and equipment-intensive.

Frank Drake conducted the first search in 1960, using the 85-foot antenna at the National Radio Astronomy Observatory in Green Bank, West Virginia. He called his endeavor Project Ozma, after the queen of the land of Oz. This search ultimately developed into Project SETI (Search for Extra-Terrestrial Intelligence), which, despite losing federal funding in the 1990s, remains the most important sponsor of search and research efforts. The SETI Institute is a private, nonprofit group based in Mountain view, California. When NASA-based SETI funding was cut in 1993, SETI consolidated much of its effort into Project Phoenix (risen, like the mythical bird, from the ashes of the funding cut), a program that began in 1995 and monitors 28 million channels simultaneously. SETI hopes eventually to monitor 2 billion channels for about 1,000nearby stars. Computer software alerts astronomers to any unusual, repeating signals. So far, no repeating signals have been discovered.

SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). You can participate by running a free program that downloads and analyzes radio telescope data.


SETI researchers also guess that civilizations might choose intentionally to broad cast their presence to their neighbors, sending some sort of radio-frequency beacon into space. What portion of the spectrum might they choose?


Researchers chiefly monitor a small portion of the radio wavelengths between 18 cm and 21 cm, called the water hole. The rationale for monitoring this slice of the radio spectrum is twofold. First, the most basic substance in the universe, hydrogen, radiates at a wavelength of 21 cm. Hydroxyl, the simple molecular combination of hydrogen and oxygen, radiates at 18 cm. If we combine hydrogen and hydroxyl, we get water.

If the symbolism of the water hole is not sufficiently persuasive to prompt extraterrestrial broad casters to use these wavelengths, there is also the likelihood that this slice of the spectrum will be recognized as inviting on a more practical level. It is an especially quiet part of the radio spectrum. There is little interference here, a very low level of galactic "background" noise. Researchers reason that, at the very least, intentional broadcasters would see the water hole (which looks the same no matter where in the Galaxy one is located) as a most opportune broadcast channel.

Be a part of the research

Want to do your bit for the Search for Extra-Terrestrial Intelligence (SETI)? Download a screensaver (at www.seti-inst.edu/science/setiathome.html) that might help to find that first ET. The program uses cycles on your computer (when not in use) to process one of the largest data sets mankind has ever assembled. And if you just want to check the current status of SETI, go to their informative website:www.seti-inst.edu. The SETI Institute received a large financial boost from Microsoft co-founders Paul Allen and Nathan Myhrvold, who gave $11.5 million and $1 million respectively for the construction of a radio telescope array dedicated to the SETI search. Up to this point, searches have depended on cadging time on existing telescopes.
The Allen Telescope Array (ATA) will be dedicated to the SETI project around the clock. The first stage of the ATA is under construction. By July 2006, the first10 antennas of the ATA42(first stage) had been equipped with motors and receivers. When completed, the array will consist of 350 6.1-m telescopes. In February 2007, the first astronomical images made with the ATA were released. In addition to being a SETI workhorse, the ATA will be a powerful astronomical radio telescope.

The "Wow" signal

The Wow! signal was a strong narrow band radio signal detected by Dr. Jerry R. Ehman on August 15, 1977, while working on a SETI project at the Big Ear radio telescope of The Ohio State University. The signal bore expected hallmarks of potential non-terrestrial and non-solar system origin. It lasted for the full 72-second duration that Big Ear observed it, but has not been detected again. Much attention has been focused on it in the media when talking about SETI results. Amazed at how closely the signal matched the expected signature of an interstellar signal in the antenna used, Ehman circled the signal on the computer printout and wrote the comment "Wow!" on its side. This comment became the name of the signal.
When something truly startling happens, people say: "OMG!" or the dreaded, "Awesome!" But when Jerry Ehman sat at his kitchen table on Aug. 18, 1977, and saw six numbers and letters on the computer printout in front of him - six symbols that have become one of the grandest riddles in modern science - he chose the simplest expression of all, Just "WOW".


The circled alphanumeric code "6EQUJ5" describes the intensity variation of the signal. A space denotes an intensity between 0 and 1, the numbers 1 to 9 denote the correspondingly numbered intensities (from 1.000 to 10.000), and intensities of 10.0 and above are denoted by a letter ('A' corresponds to intensities between 10.0 and 11.0, 'B' to 11.0 to 12.0, etc.). The value 'U' (an intensity between 30.0 and 31.0) was the highest detected by the telescope, on a linear scale it was over 30 times louder than normal deep space.
The intensity in this case is the unit less signal-to-noise ratio, where noise was averaged for that band over the previous few minutes. Two different values for its frequency have been given: 1420.356 MHz (J. D. Kraus) and 1420.4556 MHz (J. R. Ehman).

The frequency 1420 is significant for SETI searchers because, it is reasoned, hydrogen is the most common element in the universe, and hydrogen resonates at about 1420 MHz, thus extraterrestrials might use that frequency on which to transmit a strong signal. The frequency of the Wow! signal matches very closely with the hydrogen line, which is at 1420.40575177 MHz. The bandwidth of the signal is less than 10 kHz (each column on the printout corresponds to a 10 kHz-wide channel; the signal is only present in one column).


The location of the signal in the constellation Sagittarius, near the Chi Sagittarii star group. Because of the design of the experiment, the location may lie in either one of the two red bands, and there is also significant uncertainty in the declination (vertical axis). For clarity, the widths of the red bands are not drawn to scale; they should actually be narrower.

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2 comments:

  1. You might be interested in the SETI Challenge: http://seti.matthen.com/

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