Is there anybody out there? The year 2010 will mark the 50th anniversary of humanity's strangest scientific quest: the use of giant radiotelescope dishes to listen for radio messages from alien beings in space. So far, the search has been a complete bust. The radioastronomers keep listening, but the stars aren't talking to us -- not yet, anyway.

Odds are that nobody out there knows we are here,if they exist at all, so nobody is actually trying to signal us. Any signal received by us, will be an accident.

http://www.sfgate.com/cgi-bin/article.cgi?....DTL&type=books

you gotta remember, that with the current funds, SETI can only monitor 3 procent of the skies... what are the chances that somebody will actually contact us there, in a wavelength and in a readable signal any time soon?

I don't think this is the way to go by...

I think they're screening lol but all they're covering is 3%? if there is life within distance of our signals then those are pretty low chances

Some might say that they have superior technology, thus we cannot hear them, but my theory is that at least one civlization would be in the same era as we are. Then some may say that they are to many light years away, and then we are truly wasting our time. The only thing SETI may do, is find radio waves from a civilization like ours relativly close to our own solar system.

What this indicates to me is that if they (advanced ETs) are out there, they most likely aren't close (as relates to interstellar distance) to our solar system. It doesn't mean that there aren't any ETs, but it does seem to indicate that the galaxy isn't chock full of technologically advanced civilizations as one sees in Star Trek. Just my opinion.

Yeah, they'd be using radio signals.

If not radio? One approach, variously proposed by Tim Castellano (NASA), Ray Villard (Space Telescope Science Institute), and yours truly, is to assume that some ambitious alien astronomers using the transit technique have detected Earth. In other words, they have found our world because it blocks a small amount of light as it passes in front of the Sun as seen by them. This once-a-year eclipse is an event that both we, and any extraterrestrials who have observed it, will know. They might choose to send their laser flashes in our direction during these transits, on the assumption that we were clever enough to figure out the synchronization scheme.

Of course, this requires that the aliens have precise knowledge of the distance to our solar system, and the Suns motion through space. For an advanced society, that might not be too much to ask. In other words, with a collection of mirrors, a small laser, and a computer to run it all, a knowledgeable and entrepreneurial extraterrestrial could produce detectable signals with only as much power as a handful of batteries could supply.

Do you have a link to this story of those NASA figures?
Didn't know that THEY found us and we not them?

The 3 percent figure is not so much about funding and more to do with the fact that SETI has been looking using the Arecibo Radio Telescope. This is the largest and most powerful radio telescope in the world but is built into a natural bowl in the ground. As a result it can esentially on "see" straight up. The end result is that it can only observe about 3% of the sky.




Why? Optical wavelength and infra red-lasers can carry far more information for your dollar and are less likely to be absorbed by interstellar gas and dust. This is why optical SETI is about to start it's search.

We have only been sending out radio signals for a century. That means that only civilisations within 100 light years of earth will know we are hear. In terms of the size of the galaxy that is still in the same strret as us. What's more if a civilisation as close as 70 LY has picked up our very first radio transmissions and relpied straight away we still have 40 years until we get their message.

Hello there

This is my fist post and ild like to contribute to this thread by giving the following opinon.

We as a human race are seen with war hungry characteristics. Why would an Intelligant race want to show there location to race which only bring distruction. Not only do we kill other life forms, we bring death among our own race! Along with the simple fact that we are distroying our home planet.

My personal believe is that a life form out there knows were we are but are reluctent to show there whereabouts.



Regards.

I think listening for radio signals from Alien civilizations actually reflects bias on the part of our civilization: that aliens, like us, will develop radio technology and use it. My beliefs are

1)Alien intelligence may not take a form that develops what humans would describe as 'technology;'
2)Aliens may develop technology, but it will not necessarily lead them to radio technology.

Both of the above might explain why we haven't received any messages yet. We might very well be the only civilization in this galaxy, or even neighborhood of galaxies, which develop technology leading into usable radio technology. Intelligent life could be in abundance, but we would have no signs, and no way of communicating with it.

The first of your points is quite possible but in that case how do you suggest we look for them? We can only search for species which have developed technology similar to ours. It is unlikely that a technological species will skip radio all together. The laws of physics are the same for everyone.

I wasn't suggesting that we stop searching for radio signals; there is always the possible, however remote, that a radio-using civilization is close enough to be detected.

As for technological civilizations, I think you are making the (possibly invalid) assumption that a technological civilization necessarily 'progresses', and wouldn't 'skip radio.' I disagree strongly with that belief; even in the millenia since the discovery of agriculture, we have had long periods of technological stagnancy. The main method of land transportation in 1800 CE, for example, was the same as that in 1000 BCE. It's easy to imagine an alien society becoming stagnant, or technologically static (particularly if their society has a focus on being societally static).

That doesn't rule out radio-using civilizations; however, it does mean that even if intelligent alien life is common, radio-using intelligent life could still be rare enough that we might not pick up one of their signals in the next century or millenium, particularly since we've only been receiving for the past few decades.

I disagree that technological progress has stagnated in the past. It has just progressed sloowly. Once the industrial revolution occured (the point which we truely became a technological race) advances have occured spectacularly quickly.

In terms of SETI "technological" is generally taken to be a species which is capable of interstellar comunication, ie at least our level of technology.

You are, of course, correct that we can make no assumptions about other species.

Patsp recently posted about another interesting telescope in the works

Article titled: "Harvard telescope looking for aliens"

Link to CNN full article, dated April 11, 2006 found here:
http://www.cnn.com/2006/TECH/space/04/11/e...reut/index.html

Patsp posted about this subject here: http://www.unexplained-mysteries.com/forum...showtopic=66545

Maybe in 1,000 years or so we'll have all this figured out. But never say never.

I think that we need to use other waves besides radio, since the might not be using radios.

Radio astronomy isn't exactly the same thing as radio used in broadcasting. Even if ET wasn't using radio waves as a means of communication, they would still be able to discern patterns indicating artificial origin...they'd know it was from an intelligent source.

One day, it occurred to me that an optimally-compressed radio signal would look like noise. Then I read somewhere that such a signal would look exactly like black-body radiation. So would we necessarily even recognize spaceborne radio signals of intelligent origin?

They look for narrow-band signals, the ones only a few Hertz or less wide. Such narrow band signals indicate something artificial. Natural cosmic noise; pulsars, quasars, and interstellar gas of our own Milky Way, just don't make radio signals this narrow. The static from natural sources is spread all across the dial...not in a narrow bands. They also look for something that repeats, indicating something other than a random fluke.

Hello all,
Even if by some miracle they would actually detect signal and prove it’s not naturally occurring, wouldn’t the signal be too old by the time it reaches us to be of any use? All it would prove would be that at one point someone intelligent sent it, but may not even exist anymore.
Also I have to agree with one of the previous poster, seriously why would anyone who is more advanced want to contact us at a present time. Accidentally .. maybe. Intentionally .. they would have to be crazy.

On the first point that would depend on how far away they were. A signal from a civilisation 150 light years away would only be 150 years old.

On the second point, if they are more than 100 light years away they won't even know we exist yet. It is quite possible that an alien species would be sending signals into space to signify that they exist without even having considered that a technological species could be war-like. If they use radio communications in the same way that we do then (like us) they will be advertising their existence whether they want to or not.

It is highly unlikely that an extra-terrestrial species capable of interstellar communication would have anything to fear from us anyway. We have only had the technological ability for radio communications for a little over a century. We are a long way off of having interstellar spaceflight capability.

It is highly unlikely that two separate species on two separate planets would develop the same technological capability at the same time. As we are very new to this it is highly likely that any species that has radio capability is going to be more technologically advanced than us. We probably have more to fear from them than they do from us.

I agree, at infrared wavelengths, you could up the bit rate to a gigabyte per second over long distances, and a hundred times more over shorter spans (say less than 1,000 light-years). These transmission speeds are largely set by the dispersive effects of the hot gas that fills interstellar space, and they vary a bit depending on direction and wavelength. But the point is, theres no need to skimp on the information you transmit to cosmic listeners. The data pipe is fat.

For example, a society outfitted with an infrared laser of sufficient power could send the equivalent of the Encyclopedia Britannica to a million solar system targets in a day. In this way, an inquisitive civilization could ping large numbers of worlds, thereby raising its chances for successfully signaling a planet inhabited by thinking beings.

Keep that in mind when you think of contacting other societies with something akin to the Pioneer plaque. Sure, that gold-plated greeting card was a great start, but if were really thinking about interstellar messages, we should think big.

Forget about sending mathematical relationships, the value of pi, or the Fibonacci series. Rid your brain of the thought (no doubt borrowed from Close Encounters of the Third Kind) that aliens are best addressed with musical arpeggios. No, if we want to broadcast a message from Earth, I propose that we just feed the Google servers into the transmitter. Send the aliens the World Wide Web. It would take half a year or less to transmit this in the microwave; using infrared lasers shortens the broadcast time to no more than two days. And voala, we get that extraordinary answer in a thousand years or so. Sure, you and I wont be around, but imagine the one who does "picks up the phone".

they did find something once, it was named WOW.

The problem with the WOW signal is that as it has never been repeated there is no evidence that it was artificial in origin.

The CMB has the kind of thermal spectrum you mention. But, it usually ranges about 30-100 GHz (up to 150 GHz ).

Molecular clouds absorb UV etc., and re-radiate from ~20 GHz (60 cm wavelength) and up into the micron range (infrared). Moreso, than interstellar gas, and more like a black body than interstellar gas.

Which actually makes interstellar gas a more quiet competitor, especially 1.42 to 1.64 GHz, optimal SETI frequencies.

Bandwidths thinner than 300 Hz are probably artificial.
And, maybe the raw data is not compressed.

Interstellar Signal from the 70s Continues to Puzzle Researchers.

http://www.space.com/searchforlife/seti_sh...wow_021205.html

Keep on looking, theres bound to be something out there !

FACE IT , WE ARE ALONE IN THE ENTIRE UNIVERSE. UNLESS MANKIND GOES TO THE STARS BEFORE OUR SUN KILLS EVERYTHING ON EARTH , LIFE WILL FOREVER BE LOST.

That seems like an unreasonably pessimistic view, and I've done some layman's research through books on geology, abiogenesis, evolution, and the formation of stars and solar systems. Although we haven't found out exactly how life might have originated on this planet, it seems likely that it wasn't too difficult for it to do so, considering that the first measurable signs of life were only a few hundred million years after the Hadean period in the Earth's history (basically, when the planet was still getting heavily bombarded with asteroids, comets, and the like, due to the solar system's young age).

That doesn't mean, of course, that alien life will be 'intelligent' by a human standard, or think or use technology in a human way, or even use radioi technology period. It just means that, considering how quickly life arose on earth in liquid water so soon after the Earth became at least basically habitable (i.e, there was no more danger of its surface suddenly being changed in succession), it doesn't seem likely that life would be that rare.

It's possible that we could be the lone intelligent life in our galaxy. However, it's also possible that any advanced ET life is simply so far away from us that this is why we can't detect them. As for being alone in the entire universe...there's no way for us to assess the validity of a statement like this. It's equally possible that some galaxy very, very far from us is teeming with advanced life...there would be no way we could tell!

Considering the distances involved, I will agree that for all instensive purposes we certainly do appear to be *on our own* any way you cut it. This could change...but I wouldn't advocate holding one's breath.

I thought of another thing the other day,the martian meteorite ALH84001.
Any life we find in this solarsystem might not be alien at all, ever heard of the "panspermia" theory. What if it came from early Earth and got blasted into space. To Mars,etc.
I know, the gravity of the Sun.....!

Tests on Mars rock reveal life can jump between planets.

http://spaceflightnow.com/news/n0010/29marsmeteor/

They haven't confirmed that the shapes in the meteorite were actually life forms, but the idea is possible. Heck, there are bacteria now living on the surface of the moon due to the Manned Missions.

Hi Hazzard,

This thread, Has Earth spread life in the Solar System ?, in the Main Front Page News forum might interest you.

Hubble Deep Field


or download


http://www.astrographics.com/HDFVideo/Movies/HDF_320_240.mov


Constellation: Ursa Major

R.A. 12h 36m 49.50s Dec. +62° 12' 58.0"

“To summarize, the Science paper of McKay and co-workers leaves many unanswered question. As they forthrightly state, their paper is NOT PROOF OF LIFE ON MARS. Their paper presents evidence that, on its surface, is consistent with ancient life on Mars; McKay and co-workers believe that the evidence is more consistent with life on Mars than any other explanation or explanations. Almost all of their conclusions can be disputed and will likely be disputed.

From my perspective, their strongest conclusion is that ALH 84001 contains polycyclic aromatic hydrocarbons (PAHs) that formed on Mars. These PAH molecules may be related to martian micro-organisms, as McKay and co-workers suggest. The PAHs might also have formed without assistance from living organisms, in what might be called a prebiotic organic chemistry. Proof of a prebiotic organic chemistry system in Mars would be nearly as exciting as proof of life itself. “


Allan H. Treiman, Lunar and Planetary Institute
August 21, 1996


Pyranene dye encapsulated in various sizes of vesicles made from an acid extract of the Murchison meteorite-

Cross section, Murchison fragment-

Cross section 2, Murchison fragment-

Wasn't that the truth!! In the decade since the discovery many explanations have been put forward that don't involve life. There are still arguments amongst the scientists as to the temperature these features were formed at. Some experiments suggest that they were formed at temperatures far too high for them to have been formed by life.

Ten years on we still do not know if there was/is bacteria on Mars. We probably won't know for sure until samples are returned from Mars.

What we need is another Viking-style mission, this time to the north pole of Mars, or anywhere where there might be liquid water. I was under the impression that the last probe the US sent actually failed.

good point. i have wondered ,that if advanced beings exist, that perhaps there is a quarantine policy they would promote on civilizations that are advanced enough to send transmisions into space and recieve them, but are sociologically inept. im not saying this is the case, its just a pondering ive had on the issue. because if we EVER find signs of et life, we will do everything in our power to get there and inevitably screw with them as much as we screw with ourselves, and vice versa. that wouldn't make for a healthy neighborhood. lol things would , in time, deteriorate into some star wars like galaxy lol perhaps keeping all the uncivilized heathens from knowing about each other is the best way to promote a safe neighborhood.

or it could just be simple darwinian evolution. the top species keeps all the lesser species down on purpose to further promote themselves. perhaps when a species shows the ability to do amazing things, the more advanced species whipes them out. lol

but who knows. there may not even be alien life.

Well, I still think ET might not be "taking our calls" due to the distance. Just check out Waspie Dwarf's sig line. We're probably just too far away from ET for them to have even noticed us yet! If a couple of hundred years pass and there's still no answer...then one has to wonder if anyone is really out there, or if we're being ignored.

How easy would it be for them to learn of our existence? If theyve already built planet-finding telescopes, comparable to, or slightly better than, the one that NASA will be hefting into orbit in the next dozen years, then they could detect the Earth. With substantially larger telescopes, they could find our planet from hundreds or even thousands of light-years distance. Not only that, but they could also spectroscopically sample the light reflected from our atmosphere, and learn that it has large quantities of oxygen and methane, tell-tale markers of biology.

In other words, aliens , even relatively distant aliens, could make straightforward astronomical observations that would prove that the third planet from the Sun hosts life.

Excellent observations! So where does this leave us? Either ET has already found us and has answered back (the message is on it's way?), ET is ignoring us for some reason, ET is less technologically advanced than we are (hasn't looked yet), or ET simply doesn't exist. Not very satisfying, no way to really know which choice is more likely correct!

Maybe E.T does'nt want to talk just yet..? We're too busy killing one and other..! Maybe when we have grown up a little then we can all act civilised and start a dialogue between us and the friendly alien visitors..?

Maybe ET's already here. Nah.... no maybes about it. lol

Whilst this is true it would only notify them that there was life on Earth, not that there is intelligent life. If simple life evolves quite easily there could be many thousands of planets they have detected which have life. It could be that they have so many targets they haven't got around to saying, "hi" yet.

Only civilisations within about 50 light years will have had time to realise that we are technologically advanced enough to receive a radio signal and sent a reply in time for us to have received it.




Two more possibilities:

1. They are so advanced that we can no more recognise their existence than an ant can differentiate between a natural hill and a tall building.
   
2. They are so far from being truly advanced that have politicians and they have cancelled ET's SETI budget.

Good point. So how could the aliens learn that high IQ creatures crawl the Earth? For them to see the Great Wall of China, the lights from our cities, or even the cities themselves, would be extremely difficult. But as virtually every reader of these posts knows, our radio signals are dead giveaways of terrestrial technology. The aliens could "hear" us far more easily than they could see us.




Right again.. A rather easy task would be to detect our military radars. The bigger ones typically boast a megawatt of power, and are focused into beams that are a degree or two across. There are enough such radars that, at any given time, they cover a percent of the sky or so. The signal from the most powerful of these could be found at 50 light-years distance in a few minutes time with a receiving antenna 1,000 feet in diameter. Indeed, these military radars are the only signals routinely transmitted from Earth that are intense enough to be detectable at interstellar distances with setups equivalent to our own SETI experiments.

Bottom line? With radio technology slightly more advanced than our own, Homo sapiens is detectable out to a distance of roughly 50 light-years. Within that distance are about 5,000 stars. And each day, a fresh stellar system is exposed to signals from Earth.

One has to consider that even if ET notices our signal, and immediately "hollars back"...it's going to take 50 to 100 years for us to receive their reply! That's assuming that they desire to "talk" to us...perhaps ET is shy?

I have never seen a picture of an alien with clothes on, running around naked is not my idea of shy.

Not to mention how chilly that must be? Those skinny little dudes have 0% body fat...*burrr*!