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Radio search for ET draws a blank
BBC News Online ^ | Thursday, March 25, 2004 | By Dr David Whitehouse

Posted on 03/28/2004 8:38:01 AM PST by Momaw Nadon

Astronomers have completed their most sensitive search yet for radio signals from intelligent life in space.

They believe the best way to find ET is to look for a radio signal. Such signals can travel vast distances.

The Arecibo radio telescope in Puerto Rico, supported by Jodrell Bank, searched over a period of 10 years.

The scientists looked at 800 nearby stars with no evidence of a signal from ET. They say they have learned a lot, and plan another search next year.

From the ashes

The last star scrutinised by Project Phoenix - the most powerful search for intelligent life in space ever carried out - was HD 169882, a fairly ordinary star lying just 88 light-years away.

The result was that no signals indicative of an intelligent origin are coming from it, at least during the time it was observed.

So if there are any aliens on a planet circling that star then perhaps they are not interested in signalling, or are doing it in a way we cannot yet detect.

Project Phoenix was so-named because it rose from the ashes of a US space agency (NASA) initiative to search for intelligent life in space that was cancelled by US Congress in 1993.

Despite this setback, the scientists involved were determined to carry out their search.

"When the 'termination' order came from Washington, most of the equipment was on lab benches. We were immediately faced with three challenges: raise private money, get NASA to loan us the equipment and get it working," Peter Backus, project manager for Phoenix, told BBC News Online.

After the initial scramble, the scientists managed to get an Extra-Terrestrial Intelligence (ETI) search system built and used it on the Parkes radio telescope in Australia in February 1995, just one month later than the original Nasa plan.

No signal

Much of Project Phoenix's time was spent on the world's largest radio telescope, the 330-metre dish at Arecibo, which takes advantage of the natural topography of Puerto Rico's mountains.

"Over the years we have observed about 800 nearby stars over billions of frequency channels at high sensitivity," says Backus.

"No other search covered as many frequencies or achieved the same sensitivity. It was the only search capable of detecting ET transmitters with power comparable to our own military radars."

One of the problems in looking for signals from intelligences in space is that signals from Earth can interfere, so the scientists have to have a reliable way of discriminating between ET and terrestrial interference.

Phoenix pioneered a technique of "real-time interference monitoring" using a second radio telescope to determine if any suspicious signal was actually coming from deep space.

Expanded search

No suspicious signal survived that test, but the astronomers are not down-hearted; they know that ET could be detected tomorrow, in a thousand years, or never.

They say a search with an outcome that could be one of the biggest scientific discoveries of all time is worth the effort.

"We've learned a lot about searching for Eti. We'll carry those lessons and the new search system to the Allen Telescope Array (ATA)," Backus adds.

"Later this year, we'll be using the ATA with 32 small dishes. As the array expands, we'll start a new targeted search covering several hundred thousand stars.

"As I look back over the past 10 years I'm very proud of what we have achieved - the most sensitive and comprehensive search of our galactic neighbourhood.

"Conclusion: we live in a quiet neighbourhood."


TOPICS: Culture/Society; Miscellaneous; News/Current Events; Philosophy; Technical
KEYWORDS: alien; aliens; allentelescopearray; arecibo; ata; backus; blank; crevolist; deepspace; et; eti; extraterrestrial; intelligence; jodrellbank; nasa; peterbackus; planet; projectphoenix; quiet; radio; radiosignal; radiotelescope; search; signal; signals; space; star; stars; telescope
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FYI and discussion
1 posted on 03/28/2004 8:38:02 AM PST by Momaw Nadon
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To: Momaw Nadon
"Conclusion: we live in a quiet neighbourhood."
And the school district is pretty good too.
2 posted on 03/28/2004 8:43:16 AM PST by Asclepius (protectionists would oursource our dignity and prosperity in return for illusory job security)
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To: Momaw Nadon
Actually this is PROOF that there are ETs out there, and that they are very, very clever.

Only the smartest aliens would realize we are looking for them. This shows they have the intelligence AND the wherewithall to mask their radio signals.

The only question is; why are they hiding, when will they reveal themselves, and most importantly, what are their nefarious plans?

This is bad news folks, I can feel it. I'm going to keep plenty of rolls of foil around to make those double-strength hats. They are coming, it's only a matter of time.
3 posted on 03/28/2004 8:43:18 AM PST by ElkGroveDan
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To: RadioAstronomer; longshadow
Is this worth a ping to the list?
4 posted on 03/28/2004 8:49:32 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: Momaw Nadon
I've convinced myself that it's almost useless to search for ET.

I assume that with higher technology, communication will be more focused. What I mean by that relates to how we communicate now. All of our radios send out EM waves in a sphere, and our satellite dishes direct them, but the density of the waves decreases with distance because they diverge.

I think that advanced civilizations will be using technology so that they send out a very small fraction of energy that is aimed much more precisely at its target to communicate.

This saves on energy used, as you aren't just dumping EM waves to space, and also makes it impossible to eavesdrop because stray waves just won't happen.


Not only that, but i find scenarios such as in the movie "contact" (if that was the correct movie) with Jodie Fisher completely fictional.

Why would an advanced civilization want to waste its time helping out someone that hasn't even proved it can survive long enough to explore its own solar system, let alone travel the stars? The reprecussions of providing free technology to those that haven't developed it themselves could start wars unlike any we've seen.
5 posted on 03/28/2004 8:53:01 AM PST by anobjectivist (Publically edumacated)
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To: ElkGroveDan
..Only the smartest aliens would realize we are looking for them. This shows they have the intelligence AND the wherewithall to mask their radio signals.

"point-to-point comm. hub" BUMP

..got my triple layer tin-foil hat on...triple layer you can't be too safe. :)

6 posted on 03/28/2004 8:53:20 AM PST by skinkinthegrass (Just because you're paranoid, doesn't mean they aren't out to get you :)
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To: ElkGroveDan
Naw, naw, naw. You got it all wrong there with the tin foil hat there Elkgrove. To clearly block out all of humankind back chatter/interferance you have to encase your whole head in foil. Then to hear the aliens you have to open earholes in the foil and install wave-guides made out of foil encrusted toilet paper rolls.

That's the way I do it.

:)
7 posted on 03/28/2004 8:54:20 AM PST by myheroesareDeadandRegistered
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To: Momaw Nadon
I bet they actually got a signal of the aliens' version of "The Howard Stern Show" and they just concluded that there really is no intelligent life out there.
8 posted on 03/28/2004 9:00:34 AM PST by CzarNicky (The problem with bad ideas is that they seemed like good ideas at the time.)
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To: anobjectivist
Most people assume that aliens from a different planet would be very eager to communicate with us once they realized we existed. However, the sad reality is that we are likely to appear as hopelessly prehistoric from their point of reference. They will likely look at our planet in the same manner that we look at an anthill. They might even give it a kick - just for the hell of it.

9 posted on 03/28/2004 9:10:13 AM PST by SamAdams76 (I'm voting for John Kerry until I vote against him in November)
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To: Momaw Nadon
Update: Signs of extra-terrestrial activity picked up on AM radio
10 posted on 03/28/2004 9:23:56 AM PST by joebren
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To: SamAdams76
They might even give it a kick - just for the hell of it.

No, we'll be kept on as wards of the new overlords. We'll simply be declared part of the natural environment and put on an endangered alien species list and our planet labeled as a special endangered alien species habitat. To your ordinary alien life forms, our world will be off-limits or so hopelessly bound in alien red-tape that it's hardly worth the effort to visit us. Only the most elite aliens will be allowed to visit and cherry-pick our planet's resources of minerals, flora, fauna, and personae.

Who knows? It may be happening right now!!!

11 posted on 03/28/2004 9:25:43 AM PST by BradyLS (DO NOT FEED THE BEARS! Nor the overlords ;-))
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To: Momaw Nadon
Well imo if they are looking for ET's they are looking in the wrong direction..
If they are looking for real life in the Heavens look no further than your family bible
He lives
12 posted on 03/28/2004 9:35:33 AM PST by joesnuffy (Moderate Islam Is For Dilettantes)
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To: Momaw Nadon


13 posted on 03/28/2004 9:44:52 AM PST by petuniasevan (Life is cheap. It's the accessories that kill you.)
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To: Momaw Nadon
"Astronomers have completed their most sensitive search yet for radio signals from intelligent life in space...

...and came up empty, just like on earth!
14 posted on 03/28/2004 9:46:37 AM PST by observer5
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To: anobjectivist; Momaw Nadon; PatrickHenry; Piltdown_Woman; longshadow; Physicist; ...
I've convinced myself that it's almost useless to search for ET.

In a way I agree with you. Moore's law has affected the Drake equation in ways we don't even know yet. I personally think the Fermi Paradox is pure BS and not well though out, however, the Drake equation seems to have stood up to scrutiny.

SETI (at least the current trend) is searching for extremely narrowband carrier signals that Doppler shift due to planetary rotation. The Doppler shift is extremely important since if it is not there, we know the signal is either terrestrial or an artifact of the equipment itself. The other thing that is very important is the two-antenna approach. If two antennas, separated by a thousand miles, were pointed at the same patch of sky, this would not allow a satellite to "spoof" the system. First, the likelihood of it being within the footprint of both antennas are exceedingly small, and the Doppler characteristics between the two antennas would rule it out if such a thing happened.

All that said, I agree with the advances in communications technology can cause a search to be futile for many types of broadcasts. Frequency hopping spread spectrum and the like will make it far harder to detect a tool building species that uses radio (EM).

To be fair to the other side there is another factor in this conjecture. A race is progressing along and figures out that the electromagnetic spectrum is the only real practical method of long-range communications. So high-powered transmitters are built as this technology is in its infancy. As the engineering and science of radio advances, they figure out that tight beam, spread spectrum, synthetic aperture, frequency hopping, etc. are a way of not only saving power, but also bandwidth. So for the first 50 years they have been "bleeding" EM into space across a huge range of frequencies into and ever-increasing sphere of radio noise. However, do to technological advances, this RF that is being bled into space quiets down dramatically.

Now, lets jump a few years. This race has expanded off its initial planet and is exploring the solar system it resides in. (IMHO, star travel still remains firmly in the realm of SiFi) Somehow they have to communicate. So again high power transmitters are employed to accomplish this. Light is not out of the question, however, microwave is easy, cheap, less pointing accuracy requirements, and wont be drowned out by the star. So suddenly this race again is radiating RF into the universe. So according to this scenario, a race can emit RF then grow silent for a time, and then restart emitting RF.

I also agree the movie "Contact" is pretty shallow in many ways. Headphones? Not a chance. Most SETI searches are done with computers looking at millions of frequencies simultaneously. Also, SETI is not looking for, nor is it expecting any modulation. That would long ago have been lost in the Interstellar Medium (ISM). All that can reasonably be expected to be detected a faint signal from the narrowband carrier itself. In fact due to the signal-to-noise (S/N) characteristics, the narrower the band that is being searched, the better. Some searches are looking for signals that are no wider than .8 Hertz.

Just my two cents.

15 posted on 03/28/2004 10:03:13 AM PST by RadioAstronomer
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To: RadioAstronomer
I donno. It's a big galaxy. They could be out there ... somewhere. But they could be so far away that we might miss each other by millions of years. In this, as in so many other things, timing is everything.
16 posted on 03/28/2004 10:41:55 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry
Indeed it is! And frequency, direction etc. :-)
17 posted on 03/28/2004 10:42:48 AM PST by RadioAstronomer
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To: VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Physicist; LogicWings; Doctor Stochastic; ..
PING. [This list is for the evolution side of evolution threads, and some other science topics like cosmology. Long-time list members get all pings, but can request evo-only status. New additions will be evo-only, but can request all pings. FReepmail me to be added or dropped. Specify all pings or you'll get evo-pings only.]
18 posted on 03/28/2004 10:53:12 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: anobjectivist
I've convinced myself that it's almost useless to search for ET.

Not if you can build a full career and retirement out of it!
Assuming you can get money from tax-paying suckers and from folks so rich they've
run out of other projects to fund (e.g., Paul Allen of Microsoft $$$ just gave some
more funds to the ET search.)
19 posted on 03/28/2004 10:53:24 AM PST by VOA
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To: petuniasevan
I'm convinced that the aliens come to earth to obtain the ONE THING that we produce better than anyone else in the universe. I'm referring, of course, to DUCT TAPE!
20 posted on 03/28/2004 10:53:26 AM PST by The Duke
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