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This exoplanet orbits the star Gliese 667 C, which belongs to a triple system. The six Earth-mass exoplanet circulates around its low-mass host star at a distance equal to only 1/20th of the Earth-sun distance. The host star is a companion to two other low-mass stars, which are seen here in the distance.
By Elizabeth Howell
Space.com
Intelligent alien life is likely relatively rare throughout our Milky Way galaxy, with fewer than one in a million solar systems harboring civilizations advanced enough to send out radio signals, a new study reports.
A research team that includes famed alien hunter Jill Tarter — the model for astronomer Ellie Arroway in Carl Sagan's famous book "Contact" — surveyed dozens of planet-hosting stars for radio signals from alien civilizations. They turned up nothing.
"No signals of extraterrestrial origin were found," the researchers conclude in the study, which has been accepted for publication in The Astrophysical Journal.
Searching for signs of intelligent life
The team selected 86 stars using data from NASA's planet-hunting Kepler space telescope, and also observed 19 stars that serendipitously fell within range as they searched the primary targets. (One planet candidate turned out to be a false positive, reducing the total number of targets to 104.) [Gallery: A World of Kepler Planets]
University of California, Berkeley
In the next stage of research, alien hunters plan to listen in on communications between two exoplanets.
The researchers were working with the catalog of Kepler planetary candidates, which at the time included 1,235 possible exoplanets. (That number is now up to 2,740, with 105 of them confirmed to date.)
Radio signals in narrow, focused bands are a possible indication of intelligent life, given that humans generate such signals here on Earth.
So, using the Robert C. Byrd Green Bank Telescope in West Virginia, the team probed each star system for five minutes between February and April 2011. They examined the planets in a radio-frequency range of 1.1 to 1.9 GHz, which is between the cell phone and television bands used on Earth.
This range of frequencies includes a so-called "watering hole" between 1.4 GHz and 1.7 GHz, where hydrogen and hydroxyl (both components of water) emit signals from quantum processes detectable in radio telescopes.
University of California, Berkeley
This graphic illustrates the band of radiation that alien hunters searched with the Green Bank Telescope.
"The analogy is, it's the water hole where animals go in the desert, so perhaps this band of frequencies is a common gathering place for E.T.," study lead author Andrew Siemion of the University of California, Berkeley, told Space.com.
Researchers scrutinized the data for planets transmitting signals in a narrow band of 5 Hz, which is considered too narrow for transmission from a natural source. They came up empty.
One in a million
Based on their findings, the researchers calculated that fewer than one in a million stars in the Milky Way likely harbor a civilization advanced enough to send out detectable signals.
But there could still be millions of civilizations out there waiting to be found, the scientists added, since billions of Earth-like planets are thought to populate the Milky Way.
"In particular, we can offer no argument that an advanced, intelligent civilization necessarily produces narrow-band radio emission, either intentional or otherwise," the study states. "Thus we are probing only a potential subset of such civilizations, where the size of the subset is difficult to estimate."
The researchers acknowledged that narrow radio signals are subject to interference from the interstellar medium — a thin gas floating between the stars — and the solar wind, which is a stream of particles coming from the sun. However, they did not foresee these phenomena interfering unduly with their observations in the current study, given the distance of the stellar targets.
The team will use the Green Bank Telescope again to refine their search in the coming months, looking particularly at stars that have two planets aligning in relation to Earth. The scientists hope to listen in as the planets communicate with each other, if the planets are transmitting signals in the first place.
They also plan to "piggyback" on regular observations by the telescope to automatically monitor for signals as other science teams do separate investigations.
This was the first time the telescope was used for such alien-hunting work, Siemion added. In the future, more sensitive radio telescopes, such as the Square Kilometer Array, might be able to find even weaker signals than we can detect now, he said.
Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We're also on Facebook and Google+.
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Perhaps ETs are not modulating radio waves or hydrogen ions. Advanced races could be using light, such as lasers that have a more futuristic bent than we have developed. There are many other way intragalactic folks may be communicating. These need to be studied, or SETI will have failed in its efforts.
You can only fail if you give up.
Use of gravity waves for interstellar communication is much more likely than use of radio or light waves. It has recently been discovered that gravity waves travel many times faster than light. What SETI is doing is likely to turn out to be the equivalent of trying to get direct TV with a tin can and a piece of string. We'll get there, 100 years ago we didn't have cell phones, we had a few landline telephones and the telegraph.
No way, all the advanced civilizations just use ESP and talk directly brain-to-brain. We are like, so yesterday, with our smoke signal radio wave obsessions.
So if they did a study to see how many alien races there were and they came up with zero how can they say that one in a million civilizations would be advanced enough to send out radio waves?
This is not science. This is speculation. It's not even based on any facts. Because the fact is these 'scientists' know of only one planet with any kind of civilization. Earth. They have not even factuallly found any other planets that they know have any life of any kind. Might as well be watching Star Wars and base the study on that.
Or is there something they are not telling us? (eerie music plays)
@pullmyfinger: Probably using the Drake equation. That makes it progress from being a WAG to a SWAG.
I think the number that exist is fewer than one in a million. And they're probably using quantum effects such as entanglement, if not something better, for communication. I think our knowledge of quantum physics is way too preliminary for us to grasp their com channels. Having said this, if you send me a check for $100b, I promise to remedy 80% of this gap within 12 years.
We seem to assume alien life would have the same inclinations towards technological advances, including seeking life in space. What if it doesn't? It could develop in a direction to live in perfect harmony with its environment.With designs towards eliminating harm to the planet. Genetic development towards mental advancements way beyond what we can do. Using that to leap ahead, not requiring much of the technology we depend on. Who knows, they could even use their minds to help explore, as a collective, like a bee hive. To accomplish missions investigating close planets, moons in nearby star systems.Skipping the need to build space ships.
We are stuck thinking like humans.Life has must have taught us by now, it will find a way to exist in any form, in any conditions, on our planet.Surely there is no limit, as we have seen, in the remarkable, bizarre creatures beyond imagination that defy logic. Including the immortal jellyfish.
It's certainly an interesting idea, being able to reach out and discover there is alien life in the universe. Exactly how that would affect mankind, though, is another question.How would people cope knowing, they are not alone? Is in actually in their best interests to realize such a thing? As much as man has asked that question, perhaps since he has been able to understand such concept.Because no doubt, it certainly would radically alter fundamentally most peoples view of the universe.
If such contact were made, would E.T. welcome us? Because who is to say, they aren't looking for a habital place to move to. Their world dying, and we just happen to be their last hope. Like a lighthouse beacon, in the darkness. They don't need to understand or reply. Just follow the message to its source and safety.
These kinds of studies always rub me the wrong way. I know these guys are very intelligent and think this stuff through but I am always left with sense that they just are going about this all wrong..
I bet it's safer to say there is a one in a million chance that a civilization in our galaxy is advanced enough to get a signal across to the rest of us.
After all, it's our own egocentric view that suggests an "advanced" civilization would have radio technology or the desire to broadcast anything out to the universe. I can't help but think a more sophisticated civilization might have skipped the stupid ages portion of their advancement and gone straight to being just to cool for school (i.e. keeping to themselves.)
I agree with you to a point. It's not that they're being ignorantly narrowminded, it's that they're basing research on methods we are already familiar with. Our first attempt is to find something that's close to what we aleady know. If we can find results based on the same kinds of methods we use, it's definitely reassuring to know we might be on the right path if another alien race was doing the same thing. It also helps establish a control group for future experiments and research. We can look back and say "we know <blank> didn't work and that's how WE communicate so they must be possibly doing something else."
Sure there's a bit of anthropocentric narcissism in that, but at least we can establish a baseline understanding first before we start trying to create new and unexplored areas of research.
So eventually we may get smart enough not to care about them, either? Hmm...
Doug-950479, how much do you care about the random ant colony in the Amazon forest?
mob_barley, yup, for one, radio is very much still in its infancy. Second, I doubt we'll be using it much in a hundred years (if we survive). Quantum entanglement teleportation based communication will hopefully win over by then. There is a fair chance that tiny extra dimensions of space and time exist and are usable for communication without violation of any existing physical laws such as relativistic speed of light limits. We can't know until we do the R&D.
AB, Mob said they were keeping entirely to themselves, not even caring about the possibility of an alien race whose advancement was equal to their own.
Why would they bother contacting our reject of a planet? They are probably sitting back and laughing at us..
i agree bh.sometimes im repulsed by my own species.
For deep space communications, we should probably be listening in the X-ray spectrum of light. I don't imagine SETI will be doing this for several more decades. - RC
(PS - When they do finally do this, they are going to need to do it from space.) - RC
In our civilization, the "watering hole" range is not used for analog modulation which you can easily decode. The signals that carry digital information are statistically very noise-like, and don't use a prominent carrier frequency. When received from afar, you can't tell them from noise.
The age of high power AM and FM transmission is already over. It didn't last much over a century. Thus the probaibility that an alien civilization is currently at that stage is very low.
well someone better find one that fits the angry one that dosn't like to be ignored
any i think we are moving on to the indian powwow - vote for lantana to be considered a ci city with a tribe attitude and i want may Vatican credit delivered and all the stuff they locked away waiting for the right one to arrive
i don't care about titles i'm just glad to be here if no one else is-love earth it's a fun planet
ps what did you find on mars-i think that was the cause-they fought over a planet and destroyed it -so lets reverse it -we know how to if you will fund project hope lets do something unbelievable
and look at the reflections and shadows on the moon landing photos in the reflective helmet visor
anyway i hear the first man in space was shepard-wheres his fame
theres tons of these things at the meeting - who knows what they are talking about but i think they are seriously looking into military technology that may not be theres
anyway thats not my problem -i'm waiting for someone to come and rescue us tomorrow morning is fine
Out of curiosity, how many of our radio signals do we think someone living on a planet that we are trying to detect would be able to discern if they were trying to do the same thing from their planet (assuming anyone is there)?
Given the fact that most of our radio signals (and cell phones) do not have the power to be global and the signal fades far from the transmitter unless it is night time, I am not sure that we would expect our standard radio, TV, cell phone signals to go that far. Plus, probing a star (and surrounding planets) for only 5 minutes does not seem like it would be long enough for such a wide area to try to observe our frequencies in the 1.1 to 1.9 GHz range.
This leads to this point. The radio signals that we do use that do travel to another planet are different bands. For example, though the Mars Curiosity Rover uses a UHF high frequency range of 401 to 437 MHz to transmit from the ground on Mars to the orbiting Mars Reconnaissance Orbiter, the orbiter then acts as a relay and sends the signal from the Curiosity to earth over the X-band at 8 GHz or the Ka band at 32 GHz for higher data rates. (from: http://descanso.jpl.nasa.gov/DPSummary/MRO_092106.pdf) These transmitters (antenna) are also very directional in that they must be pointed at Earth for us to receive the signal.
So, should we not be looking for radio signals in these bands (well outside the 1.1 to 1.9 GHz) that a civilization might use to communicate with neighboring planets for their own space exploration which can travel between planets...we might have better luck if anyone was out there.
So I gather there's not much chance of us receiving the broadcasts of their soap operas...
This is also very unlikely and the reason is clear in the statement itself.
We have ample evidence that all life forms have the potential for extinction and humans are no exception. Through evolution, new species arise through the process of speciation, where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche and species become extinct when they are no longer able to survive in changing conditions or against superior competition. The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance.
Scientists have estimated that humans branched off from their common ancestor with chimpanzees about 5–7 million years ago. Hence, by our own estimates we have 3-5 millions years left.
That means civilizations like ours have only a 3-5 million year gap to find other civilizations in our galaxy assuming there is an overlap of both civilizations existing at the same time. The gap may even be too small to find any remnants of already extinct civilizations.
So what is my point with all this, well this is the type a studies that are used to make politician like Newt Gingrich, Barack Obama, George Bush and the rest to come up with outrageous plans to spend billions of dollars which we do not have to colonize the moon.
The blame for all this nonsense lies with NASA. As the nation's science and technology experts it is their responsibility to give the President a realistic priority list of missions that will "grow" the sciences and technologies to make our lives better and within a budget that is proportional to the expected gains/losses.
The real "Gospel" or "Good News" is that mankind potentially has countless millions (even billions) of years of growth, development and expansion ahead of them, so long as they don't fall for these ET designed and installed terminal religious "End Time" belief systems known as the Abrahamic religions. Please understand that our precious emerging human world has been under covert biocybernetic warfare attack for thousands of years already, by outside offensive totalitarian ETs who repeatedly masqueraded as Divinity toward mankind in the process of covertly installing all three of these program "End Time" religious belief systems into our world, which are all key biocybernetic warfare components of a larger ET designed PWMD, or Program Weapon of Mass Destruction, designed to crash and explode our emerging human world in a final program cataclysm of global warfare fueled with WMDs, known as the Christian Apocalypse or World War III.
Our emerging human world has actually been visited for thousands of years already by ETs, and it continues to be visited thousands of times every year by ETs who pretty much come and go as they please. These outside regional domain ETs which threaten our human world are hoping to use their eminent domain rights of military intervention in our sector of the Milky Way galaxy to move in on our precious world and take it over on the heels of the programmed Christian Apocalypse or WWIII, while once more masquerading as Divinity toward mankind, this time as the returning Christ or Messiah. Their ultimate goal is to steal and annex our extremely valuable celestial real estate and render mankind extinct here on Earth, after supposedly trying for a thousand years following their military intervention to salvage or redeem mankind from their "hopelessly violent ways". These offensive totalitarian ETs, who are a cultural singularity under the control of an advanced but delusional ET/AI system, were forced to take this covert approach at territorial conquest in our Milky Way galaxy, because there are Free Galaxy powers which reside elsewhere in our Milky Way galaxy, who currently stand in the way of overt military conquest on a stellar level. I personally know all of this because I lived at Wright Patterson Air Force base from 1951 to 1953, while my grandfather (Colonel Charles Faulkner Carter) was second in command there, and he was personally involved in the background investigation into the Roswell Incident of 1947. These same ETs overflew Washington DC for several weeks in 1952, in order to demand the return of the Roswell crash remains. They chose the middle of the Korean War to do this, since we had our hands full militarily with the Soviets, the Red Chinese, and the North Koreans. Please listen, everyone, before it is too late for mankind here on Earth! - Rick Carter
Rick, please take your meds, get off the computer and go back to bed....
Actually I found Rick's testimony very edifying. My only questions are whether the Roswell crash victims were the good guy ETs or the bad guy ETs; and if the latter, what interrogation techniques were used to elicit all this information from them...?
Rick thinks he is one of them.
This article does cover the fact that technologically advanced civilizations may not be using radio. What everyone skips over, is that there probably aren't any other technologically advanced civilizations in the known universe, let alone our galaxy. Everyone skips over the endless parameters for a truly "Earth-like" planet, which I won't enumerate here, except to list a very few items. Distance to and type of star, a Jupiter-class planet which doesn't spiral in, planet size, magnetic field, a large and relatively close moon, plate tectonics, oceans, hydrothermal vents, volcanism, land, distance to galactic center, and endless factors related to relative stability in the endlessly hazardous environment of space, such as avoiding gamma-ray bursts. To get some of those things, you probably have to have a planetary impact (as in two planets colliding). But then everyone skips over evolution. The evolution of the Universe, stars, galaxies, solar systems, the planets, and the life there. Life doesn't evolve separately from the planet, it evolves with it, each greatly affecting the other. There are many facets of the evolution of the Earth which have greatly affected life which we don't yet understand. The massive erosion of the land and the mineralization of the oceans, which appears to have been responsible for the Cambrian Explosion. The Earth freezing pole to pole, probably more than once. The endless, endless, endless factors in our own evolution. Plate tectonics and continental drift, rapid and repeated environmental fluctuations, etc. There's this bizarre notion that if you wait long enough, technologically advanced civilizations arise. I have news for you, the most successful life forms on this planet haven't been human. There are lots of more successful smaller organisms. The dinosaurs and pterosaurs were by far the most successful large organisms. We're only here because of that environmental stability issue. You need enough environmental fluctuation for evolution, but massive amounts will lead to global extinctions, as in the asteroid impact which wiped out the dinosaurs and paved the way for us, and the massive global extinction which we're now causing. The dinosaurs were never going to become technologically advanced, wrong body plan. There's this bizarre notion that technology is inherently good. It's neither inherently good nor bad, but evolution which results in advanced technology paradoxically results in life incapable of using that technology in a responsible manner, and it self-destructs. That's exactly what we're doing, destroying our only home and the life there. Technology isn't the problem, humans are. The temporal arguments were examined long ago, even if a technologically advanced civilization did or were to arise elsewhere, it wouldn't co-exist with us, and distances are too vast for known technology to enable communication, anyway. Evolution is being ignored on larger scales. The global human civilization will collapse very, very soon. It's not a date, it's a process, and it's well underway. I don't see our civilization making it to the end of this century, and it could collapse much sooner. The nay-sayers say, "It hasn't collapsed yet, it's never going to". Tell that to any of the ancient empires, the classic Greeks, the Romans, the Aztecs, the Incas, the Mayas, the ancient Egyptians, the Minoans, island civilizations, Celts, Vikings, African civilizations which Westerners choose to ignore, China (unusual in that it self-destructed internally, and yes, I'm aware that there is a "modern" China), the Nazis (remember the 1,000-Year Reich? Aspirations of being the new Rome?), endless other civilizations throughout every region of the world, including North America. The danger this time around is that technologically advanced civilization will never arise again, due to depleted resources. At some future point, likely sooner rather than later, humans will go extinct. Given our destruction of the environment and ecosystem, that could happen fairly soon, probably within thousands or tens of thousands of years, rather than the customary one or two million for mammalian species. Supervolcanoes around the world will erupt, including Yellowstone. Ice ages will occur again. The Moon will continue to recede. A new super-continent will form, and it will be much less hospitable. It will take the ecosystem 10 to 20 million years to recover from humanity, but there isn't much time left for evolution. The Sun will continue to get hotter, and even microbial life will disappear from the surface of the Earth within 2 billion years. The Earth itself will be consumed, off the top of my head, I think within 7.5 billion years. Humans aren't going to live on other planets or among the stars. This is our home, other worlds cannot be terraformed, our ecosystem can't be transplanted there. The distance between the stars will continue to increase rapidly, the stars will die out, and even black holes will evaporate. Matter will decay. Relative to the lifespan of the Universe, the time when life can exist is an infinitesimal fraction, one could easily argue that we're within the Big Bang. And we're throwing it all away. The human population has to come down dramatically, the destruction of the environment, species, and ecosystems has to end immediately, cultism has to end, all forms of anti-evolutionary technology, such as medical, must end immediately, and all energy must be renewable. Humans aren't going to do any of those things, and are doomed. The fate of the Universe is either to be an ever-expanding cold and empty vastness, or to be ripped apart by dark energy. And we're throwing away life, which we should be celebrating during its brief existence.
Geez Voice, maybe you should change your name to Voice of Doom. Reading your post makes me feel all cold and lifeless.
Well, all righty then! I suppose you could look on our self-destruction as a kind of success, unachievable by any other Earthly species, if you simply decide that the biological processes are a rare anomaly in the universe; more or less an accident (if a statistically inevitable one), and it is our evolved cognition and resultant technology which allow us to amplify and accelerate our own demise - a demise which eventually brings our constituent components back into line with the behavior of much of the rest of the universe, as we escape the detour of complex biochemistry which keeps us trapped here on this (possibly very rare) type of planet. So when we die, and our planet dies, and our solar system dies, we'll actually be more normal, and that will make us happier, since we won't have to be so self-conscious about being different.
My fear is that if an alien civilization is also looking for us, they may have intercepted signals from political commercials and decided that there was no intelligent life on our planet...and moved on.
what a waste of money.. ETs do not communicate with antiquated radio waves. they are just too slow to be practical. what you should be spending money on is new ways to encode information faster than light. THEN you will see by observing communications filling the etho of space.
Perhaps you should spend less time watching Star Trek...
Maybe ET doesn't have unlimited minutes and is just being frugal.
I like to believe that what we are on earth is quite unique. Think about it. There have been roughly 100 million species on our planet. Of all these, only one has developed advanced civilizations. Only the happy circumstance of a rogue planet striking earth at an oblique angle and spalling off a moon that creates tides has made even this possible. We just happen to be sitting in the goldilocks zone, somehow have survived a total freeze-over of our planet and made it through several asteroid hits that just about wiped out everything. The odds against our being here are long indeed, yet here we are. I doubt that conditions necessary to create advanced life forms have existed very often out there.
ET has not phoned home yet, and I doubt he ever will. Let us live with our responsibility to preserve what is perhaps unprecedented in the universe. Let's give it up for intelligent life!