Looking For Extraterrestrials Looking At Us

If there are habitable planets out there, where do we look?

[/caption]The cosmos is a very big place, how do you begin the search for exoplanets orbiting other stars? Astronomers have a few tricks up their sleeves to work out how to spot these tiny specks of distant alien worlds. Astronomers can look for the gravitational “wobble” of a star as a massive exoplanet tugs on its parent star during orbit, or more commonly, they look for the slight dimming of star light as the exoplanet passes in front of the star. In fact, the Kepler space telescope is going to peer into space, surveying 100,000 stars to do just this; not looking for large gas giants, but detecting rocky bodies that resemble large Earths with the unparalleled precision.

OK, so we have a means of finding these habitable worlds, how can we use this information to widen our search for extraterrestrial intelligence? Researchers in Israel have asked that same question, and arrived at a very logical answer. If we are to communicate with these advanced beings, perhaps we should make sure they can see us first…

The concept is simple enough. Find a star with an Earth-like transiting exoplanet (we will hopefully have a few super-Earth targets over the next three years with Kepler), aim a radio transmitter at the star and send a “Hello world!” message to the possible alien civilization living on the exoplanet. All going well (or not, depending on whether these extraterrestrials are actually friendly), we’ll get a reply from said star system in a few decades with a message saying something like “Hello world to you too!”. It would be a momentous day for interstellar communications and it would answer the one question that bugs astronomers everywhere: Are we alone in the cosmos?

So far so good, until interstellar travel becomes a reality, mankind and our new chatty alien neighbours can play a very long game of radio tag, learning more about each other as the years/decades/centuries go on (depending on how distant the extraterrestrial civilization is in the first place). But there’s a problem with this plan. What if our ET neighbours aren’t looking in our direction? What if the Sun looks like ‘just another’ star amongst the other 1010 Sun-like stars hanging out in the Milky Way? We can transmit to our hearts content, but they may never see us.

Shmuel Nussinov at Tel Aviv University in Israel asked these same questions and actually makes the search for extraterrestrial intelligence a little bit easier. With the assumption that a sufficiently advanced alien race is surveying the skies, also looking out for exoplanets orbiting other stars, they may be using the same transit method that we use to detect exoplanets. Therefore, it only seems reasonable that ET will only be able to detect Earth if we pass in front of the Sun, thus dimming it slightly for our alien neighbours to see us. If this is the case, it seems highly unlikely that any alien race will detect our existence unless they are located along a narrow angle along the ecliptic plane of our Solar System. So, if we want to open up some alien banter, we should perhaps send signals to Earth-like exoplanets spotted along the ecliptic.

Although the Earth only passes across the solar disk for 13 hours every year (as viewed by a distant observer), our star will appear to dim slightly, allowing ET to see us. Factor in the various transits of the inner Solar System planets, and our observers will see there are a few possibly habitable rocky “exoplanets” for them to transmit to. If we are already transmitting, communications can be exchanged.

What a good idea

Source: arXiv blog

The Milky Way Could have Billions of Earths

Exoplanets like the Earth might be more common than we think. Image Credit: ESO

With the upcoming launch in March of the Kepler mission to find extrasolar planets, there is quite a lot of buzz about the possibility of finding habitable planets outside of our Solar System. Kepler will be the first satellite telescope with the capability to find Earth-size and smaller planets. At the most recent meeting of the American Association for the Advancement of Science (AAAS) in Chicago, Dr. Alan Boss is quoted by numerous media outlets as saying that there could be billions of Earth-like planets in the Milky Way alone, and that we may find an Earth-like planet orbiting a large proportion of the stars in the Universe.

“There are something like a few dozen solar-type stars within something like 30 light years of the sun, and I would think that a good number of those — perhaps half of them would have Earth-like planets. So, I think there’s a very good chance that we’ll find some Earth-like planets within 10, 20, or 30 light years of the Sun,” Dr. Boss said in an AAAS podcast interview.

Dr. Boss is an astronomer at the Carnegie Institution of Washington Department of Terrestrial Magnetism, and is the author of The Crowded Universe, a book on the likelihood of finding life and habitable planets outside of our Solar System.

“Not only are they probably habitable but they probably are also going to be inhabited. But I think that most likely the nearby ‘Earths’ are going to be inhabited with things which are perhaps more common to what Earth was like three or four billion years ago,” Dr. Boss told the BBC. In other words, it’s more likely that bacteria-like lifeforms abound, rather than more advanced alien life.

This sort of postulation about the existence of extraterrestrial life (and intelligence) falls under the paradigm of the Drake Equation, named after the astronomer Frank Drake. The Drake Equation incorporates all of the variables one should take into account when trying to calculate the number of technologically advanced civilizations elsewhere in the Universe. Depending on what numbers you put into the equation, the answer ranges from zero to trillions. There is wide speculation about the existence of life elsewhere in the Universe.

To date, the closest thing to an Earth-sized planet discovered outside of our Solar System is CoRoT-Exo-7b, with a diameter of less than twice that of the Earth.

The speculation by Dr. Boss and others will be put to the test later this year when the Kepler satellite gets up and running. Set to launch on March 9th, 2009, the Kepler mission will utilize a 0.95 meter telescope to view one section of the sky containing over 100,000 stars for the entirety of the mission, which will last at least 3.5 years.

The prospect of life existing elsewhere is exciting, to be sure, and we’ll be keeping you posted here on Universe Today when any of the potentially billions of Earth-like planets are discovered!

Source: BBC, EurekAlert

Less Than 20 Years Until First Contact?

Allen Telescope Array. Credit: ATA

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The Allen Telescope Array (ATA) has come online with its initial configuration of 42 antennas. The project, led by the SETI Institute, is a non-governmental project funded by Microsoft co-founder Paul Allen in which eventually 350 small radio antennas will scan the sky for signs of extraterrestrial intelligence. To test the system, the ATA sucessfully picked up the New Horizons probe on its way to Pluto. Senior SETI scientist Seth Shostak said at an event in San Francisco Tuesday night that the array could become strong enough by 2025 to look deep enough into space to find extraterrestrial signals. “We’ll find E.T. within two dozen years,” he said.

That’s, of course, assuming the distance we can look into space will be increased with new instruments yet to be built, and that the projected computing power under Moore’s Law actually happens.

Shostak estimated that if the assumptions about computing power and the strength of forthcoming research instruments are correct, we should be able to search as far out as 500 light years into space by 2025, a distance he predicted would be enough–based on scientist Frank Drake’s estimate of there being 10,000 civilizations in our galaxy alone capable of creating radio transmitters–to find evidence of intelligent life that is broadcasting its existence.

Only time will tell.

For the New Horizons observation, made Sept. 10, operators of the ATA used a synthesized beam formed with 11 of the array’s 6.1-meter (20 foot) antennas – a method called “beamforming” that electronically combines the antennas into a single virtual telescope. The 8.4-GHz spacecraft carrier signal was then fed into the SETI Prelude detection system.

“We’re happy to be the ATA’s new friend in the sky, helping SETI to verify the operations of their electronics,” says New Horizons Principal Investigator Alan Stern. “It’s also nice to know that someone else is checking in on us during our long voyage to Pluto and beyond.”

And what does New Horizons look like to the Allen Telescope Array? This plot shows 678 hertz (Hz) of spectrum collected over 98 seconds. The New Horizons signal can be easily seen as a bright diagonal line, drifting at rate of -0.6 > Hz/second.

What New Horizons looks like to The ATA.  Credit: SETI Institute
What New Horizons looks like to The ATA. Credit: SETI Institute

Sources: CNET, New Horizons

Podcast: The Search for Extraterrestrial Intelligence

Artist's impression of the Allen Array. Image credit: SETI Institute

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You know what this show needs? More aliens. Since we don’t seem to have any visiting right now, we’re going to have to find some. SETI is an acronym. It stands for the Search for Extraterrestrial Intelligence. But there’s more to SETI than just putting up a radio telescope and hoping to catch a glimpse of an alien television broadcast.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

The Search for Extraterrestrial Intelligence – Transcript and show notes.

Messages From Earth Beamed to Alien World

RT-70 radar telescope in Evpatoria, Ukraine

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The powerful opening scene of the movie “Contact” portrays radio and television signals from Earth heading out into space. Then later in the film, shockingly, one of those signals — a televised speech by Adolf Hitler — is beamed back as a reply. Could that really happen? Could an alien civilization “find” us from our inherent noise? Or, if we want other intelligent life to know we’re here, will we have to take a more proactive or aggressive approach? Perhaps we’ll find out. Today, messages from Earth were beamed specifically at an alien world considered capable of supporting life, the planet Gliese 581c, a “super-Earth” located approximately 20 light years from us. The social networking site Bebo sponsored a competition for young people to share their views and concerns of life on Earth, and the winners’ messages were transmitted this morning from a radio telescope in Ukraine. Bebo was assisted by Dr. Alexander Zaitsev, who says the only way alien civilizations might find us is if we specifically make ourselves known.

501 photos, drawings and text messages were translated into binary format and beamed through space in a four and a half hour transmission by the huge RT-70 radar telescope in Evpatoria, Ukraine, normally used to track asteroids.

The transmission started at 0600 GMT on October 9. Oli Madgett, from the media company RDF Digital who came up with the idea, said the message “passed the Moon in 1.7 seconds, Mars in just four minutes and will leave our Solar System before breakfast tomorrow”. The media company footed the $40,000 (£20,000) bill for the transmission.

The message should reach the Gliese system by about 2029. Any reply to the messages probably wouldn’t reach Earth for 40 years.

Bebo’s intent was to raise awareness for the concerns that young people have for the future of Earth, and to generate interest in space exploration. Bebo spokesman Mark Charkin said, “A ‘Message From Earth’ presents an opportunity for the digital natives of today… to reconnect with science and the wider universe in a simple, fun and immersive way.”

Dr. Zaitsev was a consultant for the project, and is one of the world’s experts in interstellar radio communication and is Chief Scientist of the Radio Engineering and Electronics Institute, at the Russian Academy of Science. His early work helped design and implement radar devices to study Mercury, Venus and Mars and Near-Earth asteroid radar research. Lately, he has focused on interstellar radio messaging, and what he calls METI – Messaging to Extra Terrestrial Intelligence.

“The leakage is of commercial television radio is much weaker than coherent sounding radar signals, such as the Arecibo Radio Telescope or the Goldstone Solar System Radar,” Zaitsev told Universe Today. “The leakage is weakly detectable against a background of solar radio emissions. I do not say that any imaginable super-aggressive and powerful civilization cannot detect our leakage, however.”

Update 10/10: Zaitsev added that the idea of the A Message From Earth internet project was developed in 2002 from his abstract Project METI@home: Messages to ETI from home,
(in English), and (in Russian). End of update.

As opposed to SETI, the Search for Extra Terrestrial Intelligence, METI takes a more proactive approach. In his paper “Making the Case for METI,” Zaitsev and two colleagues wrote, “It is possible we live in a galaxy where everyone is listening and no one is speaking. In order to learn of each others’ existence – and science – someone has to make the first move.”

Zaitsev has been involved in several deliberate transmissions to space in hopes of making contact. “Otherwise,” he said, “centers of intelligence are doomed to remain lonely, unobserved civilizations.”

METI, as well as the Bebo project, takes a complete opposite approach from the recently formed WETI – Wait for Extra Terrestrial Intelligence.

Source: BBC

New Search for Extraterrestrials Waits for No One, Er…, Everyone

In a bold move, astronomers have begun a new search to understand and explain the origin, nature and prevalence of intelligent life in the universe. Called WETI, which stands for Wait for Extra Terrestrial Intelligence, the institute employs an entirely novel approach to achieve its goals. Instead of actively searching for extraterrestrial intelligence, the idea is to simply wait: Wait until the ETs find us. “Waiting is a notoriously underappreciated method in our efforts to search for extraterrestrial intelligence,” says the WETI website. “It is cheaper and less stressful than any other type of research. It is also environmentally friendly and does not cause global warming, terrorism or nuclear conflicts.” WETI’s overall objective? To set a new gold standard for scientifically meaningful waiting, and to provide humankind a new purpose as they wait.

The work of WETI was recently highlighted at the Dot Astronomy Conference on Networked Astronomy and the New Media. WETI officials overcame several problems, and were able to present a poster at the conference. Then they went out for drinks, presumably to make the waiting more enjoyable.

The poster introduces the very foundations of WETI, which includes the breakthrough “Brake Equation.” See the poster for more details.

In the near future, whenever they get around to it, WETI will provide a downloadable computer program that will make use of the idle time of your computer to very efficiently wait in the background. “Modern computers can wait several million times each second,” says WETI. “By exploiting this currently unused waiting potential we will collectively create the biggest waiting power ever applied to any problem on earth.”

I contacted the WETI Institute for more information and was pleasantly surprised that I did not have to wait very long for a reply. An Aleks Scholz, the Deputy Chief Executive Officer of WETI, responded to my inquiries. When asked about the response WETI has received thus far, Scholz said,” Generally positive, with a slight inclination of being confused at first, plus occasional cases of consternation. So far, however, there were no medically relevant problems related to the responses to WETI.”

The history of the WETI Institute appears to be long and muddled. “We are still working on tracking down the roots of our organization,” said Scholz. “Most of us, however, believe that it was Knarps Hoselton who originally provided the stimulus for the WETI movement with his inspirational piece of research ‘On Some Philosophical Implications of Throwing Small Stones into a Big Body of Water’ in the early 80s. Today, Hoselton is Senior Astronomer and holds the Bruno Moravetz Chair Emeritus at the WETI Institute.” In more recent years, Scholz himself, an astronomer at the University of St. Andrews, picked up on Hoselton’s revolutionary ideas and suggested combining them with networking technology. This was the beginning of the WETI Institute.

When asked how long we may have to wait for results from this new initiative, Scholz said, “We prefer to see each day of WETI as a ‘result’, providing us with one bit of information about the nature of extraterrestrial intelligence– they are somewhere else. The non-presence of aliens on planet Earth is as useful for science as their presence would be. We will not accept any notion that waiting is only useful if, finally, something happens. Instead, we consider waiting a fulfilling scientific method in its own right.”

So, is this a joke? Maybe. Or maybe not. “It seems appropriate to ponder the actual usefulness of WETI” says the WETI website. “Where do we come from? Where do we go? Can we have coffee in between?” Well, thanks to the WETI Institute, the process of answering these questions turns into a social experience – a global, conscious waiting process. With WETI, everyone at least knows that they are waiting. This provides new purpose to humankinds’ seemingly eternal waiting. We can all now wait with fierce determination.

If you find yourself not very adept at waiting, Scholz offered a few tips. “With our expertise, we can suggest a number of things: The long-established technique of fiddling your thumbs, for example, is a good start. You might also want to take a sheet of graph paper and fill in all the squares with a soft pencil. When you are finished, you could arrange for a nice cup of tea, just for a change. Finally, procrastination is always a valid option. Surely there is something you should be doing right now. Concentrate your energies on not doing it.”

In the words of Galaxy Zoo’s Chris Lintott, “This is both brilliant, and completely mad.”

Update: You can now join WETI’s “think tank,” the Effortless Action Committee. When you do you can receive an attractive certificate suitable for framing immediately — no waiting!

Communicating Via the Cepheid Galactic Internet

Cepheid Variable Star. Credit: Hubble Space Telescope

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If an alien species wanted to communicate with Earthlings, or any other civilization that might be out there, how might they do it? Some have proposed microwaves, neutrinos or lasers, or even moving stars around into patterns. But why wouldn’t aliens just use the internet? The Cepheid Galactic Internet, that is. A group of scientists has proposed that a sufficiently advanced civilization could use Cepheid variable stars as beacons to transmit information throughout the galaxy and beyond. These stars can be seen from long distances and, the scientists say, any technologically advanced civilization would likely observe Cepheid variables as distance markers. The group of physicists and astronomers from Hawaii and California propose that Cepheids and any other regular variable stars should be searched for signs of phase modulation and patterns which could be indicative of intentional signaling.

In their paper, the group of scientists proposes that advanced civilizations hoping to communicate would want to use a form of communication with a high data rate, just as everyone on Earth would prefer broadband for their internet. Microwaves and lasers have problems with resolution and noise, while photons or neutrinos would take an enormous amount of power to send messages long distances. And moving stars around? Well, that sounds pretty difficult if not labor intensive. So how about something akin to a T1 line that is already established? All that would need to be done is to “tickle” the star, as the scientists call it, or tweak the Cepheid, to send a message. The researchers write, “Recently, some authors have driven home the point that it is far more energetically practical for transmitting large amounts of data to place long lasting artifacts in stellar systems to which the ETI (extra terrestrial intelligence) may wish communicate information (their history for example) as intelligent life matures and becomes capable of decoding this ‘Rosetta stone.’”

By “tickling” the star, with the delivery of a relatively small amount of energy via neutrinos or other forms of power pulses at the right time could trigger the Cepheid to a specific variability, and a message could be encoded within that variability.

The researchers admit the civilization attempting this would have to be highly advanced. But if some civilization has in fact created a message and sent it via the Cepheid Galactic Internet, all we have do to is open our inbox.

Who knows, they could be on to something. They’ve even discussed their proposal with Freeman Dyson. “It may be a long shot,” they write, “but should it be correct, the payoff would be immeasurable for humanity. The beauty of this suggestion seems to be simply that the data already exists, and we need only look at the data in a new way.”

Sources: arXiv, On Orbit

New Radio Telescope to Help SETI Scan Unexplored Frequencies for Extraterrestrials

Since the 1960’s astronomers have been scanning the heavens, searching for radio signals beamed towards the vicinity of Earth by other intelligent beings. But so far, no ET signals have been found. However, no radio telescope has been able to search the very low frequency radio spectrum, which could possibly include “leakage” of extraterrestrial “everyday” signals that a distant civilization might emit, such as television and radio signals. But a new radio telescope called LOFAR (the Low Frequency Array), will have that ability. Currently being built by ASTRON, (the Netherlands Foundation for Research in Astronomy), LOFAR consists of about 25,000 small antennas that will receive signals from space, and offers the ability to search these low-frequency type of radio waves.

According to Professor Michael Garrett, General Director of ASTRON, LOFAR is well suited to SETI research. “LOFAR can extend the search for extra-terrestrial intelligence to an entirely unexplored part of the low-frequency radio spectrum, an area that is heavily used for civil and military communications here on Earth. In addition, LOFAR can survey large areas of the sky simultaneously – an important advantage if SETI signals are rare or transient in nature.”

Astronomers believe of the approximately 100 thousand million stars in the galaxy, most of these have planetary systems. Some of these planets might actually be suitable for life and many scientists believe that life is probably wide-spread across the galaxy. However, technically advanced civilizations might be relatively rare or at least widely separated from each other.

Despite the huge distances between stars, the next generation of radio telescopes, such as LOFAR, begin to offer the possibility of detecting radio signals associated with extraterrestrial radio and TV transmitters.

Dan Werthimer, a SETI@home project Scientist at the University of Berkeley said, “SETI searches are still only scratching the surface, we need to use as many different telescopes, techniques and strategies as possible, in order to maximize our chances of success.”

Professor Garrett thinks it is high time European scientists began to support their colleagues from the United States in this exciting area of research. “I cannot think of a more important question humanity can ask and perhaps now answer. Are we truly alone in the Universe or are there other civilizations out there waiting to be discovered? Either way, the implications are tremendous.”

LOFAR will begin its scans of low frequency radio waves when the array is completed in 2009.

Original News Source: ASTRON

Doritos In Space

I’m all for the commercial use of space, but this might be a bit overboard. Back in March of this year, Ian reported on a fund raising scheme to help the United Kingdom’s physics and astronomy money woes. The scheme involved soliciting commercial companies to pay for advertising being beamed into space, supposedly directed towards potential extra terrestrial life. The manufacturer of Doritos snack chips stepped up, donating an undisclosed sum in exchange for transmitting their ad. But the Doritos people decided to turn the advertisement into a contest, and created the Doritos Broadcast Project, which invited the UK public to create a 30 second video clip that could be beamed out to the universe offering a snap shot of life on earth to anyone ‘out there’. According to a poll, 61% of the UK public believe this is just the start of communication with ET life and that we will enter into regular communication with an alien species at some stage in the future. See the winning commercial:

The winning space-ad entitled ‘Tribe’ was voted for by the British public and directed by 25-year-old Matt Bowron. It will officially be entered into the Guinness Book of Records and will be aired on the more conventional medium of television in the UK on Sunday, June 15th.

Does this really offer a “snapshot of life on Earth?” Is this the impression of ourselves we’d like to give to extraterrestrials?

The message is being pulsed out over a six-hour period from high-powered radars at the EISCAT European space station in the Arctic Circle. The University of Leicester has also been involved in the project from its inception.

EISCAT Director, Professor Tony van Eyken who will oversee the transmission said: “The signal is directed at a solar system just 42 light years away from Earth, in the ‘Ursa Major’ or Great Bear Constellation. Its star is very similar to our Sun and hosts a habitable zone that could harbor small life supporting planets similar to ours.”

Peter Charles, Head of the Doritos Broadcast Project said: “We are constantly looking to push the boundaries of advertising and this will go further than any brand has gone before. By broadcasting the winning ad to the Universe, Doritos is delivering a world first and Matt Bowron, the winner, will go down in advertising folklore. We also shouldn’t be too surprised if the first aliens start arriving on planet Earth immediately demanding a bag of Doritos.”

Wow.

Dr Nigel Bannister thinks the idea might stimulate extra public interest. “The idea of transmitting an ad into space is somewhat controversial but still of scientific interest,” he said.

“This could be a test for future very long range communications and it gives us an opportunity to tell the Universe we are here (in case someone out there is listening – like reversal of the SETI programme!).

“There could also be potential commercial interest in enterprises like this. Imagine one day that companies on Earth might wish to advertise to other planetary colonies within our solar system -for example if man ever moves to colonise Mars!”

Source: Space Daily

If ET Calls, Would We Be Told?

SETI's Alien Telescope Array (ATA) listens day and night for a signal from space. Credit: SETI

If a verified message from aliens is ever received, would the public be told about it? SETI — the Search for Extra Terrestrial Intelligence – does have an international protocol that if an alien signal is ever received, it would be disseminated among the astronomical community and made public. And of course, says Mac Tonnies at the SETI Blog, “international cooperation might be necessary in order to distinguish a legitimate alien signal from any number of phenomena capable of generating false alarms.” But what if the signal is more than just extra-terrestrials saying hello? Tonnies believes SETI’s plans for full disclosure only makes sense if the message is fairly benign. If the signal was a notice of impending doom from a black hole, supernova, or alien invasion –something we on Earth had little power to do anything about — Tonnies questions whether governments would choose to make such information public. But could something of this magnitude really be kept under wraps?

Frankly, I hadn’t really considered this scenario. When I think about SETI and the possibility of communication with an alien species, I envision, perhaps naively, what Tonnies calls the “lofty, abstract dialogue immortalized by Carl Sagan.” But of course, we have no idea of what any alien intelligence would like to say to us. If it was bad news, would governments of the world elect to withhold the information from the public?

Intrigued by Tonnies’ blog post, I contacted him to ask that question.

“I think it’s a very real possibility that generally goes unspoken,” said Tonnies, an author, essayist and blogger. “In the event of a bona fide signal, the public may only be made privy to part of it. It depends on the content and context of the message.”

Tonnies questions whether governments would elect to gamble with their respective economies and socio-political agendas for the sake of imparting knowledge that might only cause mayhem.

But wouldn’t governments want the people of the world to know so that intellectual resources could be pooled to try to find a solution to the problem? And what about the concept of an alien message bringing the world together?

“I think uniting the people of the world is the last thing governments want,” said Tonnies. “A rush to counter some cosmic threat is likely to have a war-time character, at least among scientists. And this is assuming that the threat we’re being warned about is something that can be acted upon with the technology available to us. If we happen across a generic warning, there’s no promise we’ll have the savvy to do anything about it given our level of development. If that’s the case, why would we expect prompt disclosure?”

Logically, however, it seems unlikely that aliens would call just to tell us we’re doomed. “It’s pretty foolish to expect aliens to conform to our definition of altruism — although I’m drawn to the idea of a ‘Galactic Emergency Broadcast System,'” said Tonnies. “Maybe ETs feel compelled to give less advanced civilizations a “heads up” in the event on some interstellar crisis because we might make for meaningful companionship a few million years from now.”

Maybe I’ve watched too many movies, but I’m still doubtful that an alien message, whether good news or bad, could be withheld from public knowledge. It would be too big, too transformational, too altering an experience not to be shared.

Original News Source: SETI BLog