7/25/11 Update: The website SetiStars is currently having a public donation challenge to make over $200,000 in the next few weeks
Last month, the alien-hunting Allen Telescope Array (ATA) in northern California went offline after only two years of scientific service. Originally funded by a $30 million grant from Microsoft co-founder and tech-obsessive Paul Allen, the project most recently relied on the National Science Foundation and the State of California. With a goal of constructing 350 radio antennas using multimillion channel receivers, the ATA could have had the capability of listening to the softest whispers at the farthest edges of the galaxy. Yet, like NASA's doomed Constellation program, the ATA's current bread-makers recently decided to make terminal budget cuts, putting the project to rest before it ever reached its full potential.
"The ATA was born in the wrong time in the middle of a large financial crisis," explained Dr. Franck Marchis of the SETI Institute, the group which operates the ATA along with UC Berkeley. "If the antenna array would have been ready ten years ago we most likely would have had a larger array and it would have been more competitive with respect to other projects."
Today, the SETI Institute has been reduced to pan-handling on their website – and in the middle of this year's TED conference — like a pastor collecting donations at church in efforts to wake the ATA out of hibernation. Unfortunately, everyone seems to be dropping change instead of big bills. Have people stopped believing in the possibility of otherworldly civilizations? Or has the virtue of funding intergalactic curiosity simply lost out to more worldly endeavors such as feeding the hungry, or cancer research?
For fifty years, we have been scanning the skies listening for those faint alien radio waves, and for fifty years we've heard little more than the static of space. Although we will never be able to prove that intelligent life exists outside of Earth until we make contact, science has produced logical predictions of its existence.
In the 1960's, Professor Frank Drake of Cornell University derived an equation to predict the number of intelligent civilizations currently located within the Milky Way. The resulting value fluctuates due to variable discrepancies, but the possibility of numerous otherworldly civilizations in the galaxy does hold water.
The science behind searching for these civilizations lies within some assumptions itself. It is commonly believed at SETI and other intelligence hunting groups that an alien signal is most likely to be found around 1420 MHz. Like a top-40 radio station for the cosmos, this frequency is considered to be the universal broadcasting channel. Why 1420? Because hydrogen, the most common element in the universe, resonates at this frequency when absorbing and emitting photons.
To play it safe, the ATA was constructed with an unprecedented instantaneous frequency range of 500 MHz to 11,200 MHz, just incase this prediction is invalid. Even still, two of the most likely candidates for unknown intelligence sources, the 1977 Wow! Signal and the 2003 SETI-discovered Radio Source SHGb02+14a, were both found at this frequency. Although today they are viewed as incredulous determinants for extra-terrestrial life, signals detected at the 1420 MHz frequency are still immediately flagged as potential alien transmissions.
Even though discovering the "Wow!" signal and "Radio Source SHGb02+14a" riled up conspiracy theorists in 1977 and 2004, the scientists at SETI are very adamant about proving extra-terrestrial intelligence exists with absolute certainty. The most common way of locating an alien signal uses the "signal-to-noise ratio". As a method of statistics, this calculation determines how unnatural the incoming signal is in comparison to the background cosmic static. But this postulate, which has determined signals such as "Wow!" and "SHGb02+14a" is too broad to be the only decisive factor. Dr. Paul Shuch, one of the highest regarded radio astronomers, explains the importance of repetition in one of SETI's publications, while eliminating the possibility that the source is a pulsar:
"We learned from the Ohio State “Wow!” signal that an event failing to repeat, and which cannot be verified, is no existence proof whatever. . . Any emission which appears (at least at the outset) to defy entropy is a likely candidate for an intelligently generated artifact. In that regard, periodicity is a necessary, though not a sufficient, condition for artificiality (remembering once again the pulsar)."
A pulsar, which is theorized to be the culprit behind "Radio Source SHGb02+14a," is an exhausted star that emits a focused stream of radiation as it rotates, creating a pulsing noise throughout the cosmos. The signals from the first discovered pulsars in the 1960's were actually first thought to originate from alien life forms.
More pulsars: see Motherboard's documentary on
the largest telescope on Earth
the largest telescope on Earth
Most of the researchers today believe that if a confirmed signal is discovered, it will consist of incomprehensible garble that is impossible to decipher; much like how an alien might interpret the still-traveling sounds of the first human radio broadcast of "Oh Holy Night" in 1906. But there is a possibility that other civilizations have directed messages towards Earth with an intention of communicating outside their world. In this instance, some universal message of intelligence would be the likely signal.
A number of scientists have theorized how this universal message could be constructed. On Earth, we have often theorized what type of message we could transmit that would be interpreted universally. These types of communications are commonly categorized in science-fiction as xenolinguistics with the more serious attempts being labeled as astrolinguistics. Hans Freudenthal, a Dutch mathematician, developed the first astrolinguistic language Lincos in the 1960's, which used mathematics as the common ground for understanding the information. Unfortunately scientists regarded "Lincos" as a language too tainted with human overtones for any other life form to decipher it. It was realized that the only proper way to transmit a universal message was to drop any influence from human interaction and rely solely on mathematics.
At Cornell, Prof. Drake proposed that the usage of prime numbers would be a likely tool in interstellar communication. It is impossible to develop a prime number-generating algorithm, thus, prime numbers cannot ever be generated naturally, making them ideal indicators of an intelligent society. Carl Sagan, a friend and colleague of Drake, popularized this prime number theory in his novel Contact, in which the first message received from alien forms is a sequential list of prime numbers.
To test his theory on prime number based messages, Prof. Drake submitted a binary number cryptogram at the 1961 Greenbank Conference (same conference where the Drake Equation was popularized). The participants were asked to solve the 1,271 bit code with the understanding that it came from a hypothetical alien source. Amazingly, Bernard Oliver of Hewlett-Packard was able to recognize that 1,271 is the product of the two prime integers 31 and 41.
Once the linear cipher was presented in a 31×41 grid array, a picture was formed. Oliver was able to recognize that the cryptogram was a radiogryph, which is a picture image produced by taking a string of radio data and formulating it as a table. (Radiogryphs were popularized as a tool for alien intelligence communication in the 1950's by Lancelot Hogben and the British Interplanetary Society.) This theory of using prime numbers was actually put into practice in 1974 with the SETI-transmitted Arecibo Message.
Aiming at Goldilocks
Even though the factors in determining extra-terrestrial intelligence signals have been perfected and radio antenna arrays such as the ATA have achieved significant technological gain, the search for these other worlds have always been hindered by the enormity of space. In recent years, NASA has been eliminating discrepancies in the Drake equation by hunting for the number of hospitable planets within the galaxy.
Using the Kepler Space Telescope, astronomers use a space-based photometer to measure the temporary change in a star's brightness to determine whether or not a planet is passing in front of it. Their research has given them the ability to find so-called "Goldilocks" planets: rocky, earthlike planets positioned just the right distance from their respective stars, where potential surface water can remain liquid. Currently, NASA has found 1235 planets, 54 of which are Goldilocks, orbiting 997 different stars. With 100 to 400 billion stars in the Milky Way, the number of Goldilocks planets can be modestly predicted to be in the hundreds of millions.
The discovery of these planetary systems presents a potential gold mine for SETI researchers, who previously searched for life like blind men playing darts. By reducing the vastness of space to these potential life-harboring planets, the researchers at SETI now have specific directions for where to point their telescopes. But now, without the ATA, they no longer have any telescopes. It's like losing your passport before a vacation.
Still, it's not hard to side with the appropriations committees who cut SETI's funding. We in the U.S. are currently involved in two wars, our education system is embarrassing, and the national deficit is nothing but terrifying. Why should we invest public money in something that has no economic or social payback? Even the senior astronomer at SETI, Dr. Seth Shostak, sympathizes with the alien-hunting naysayers in a recent article at the Huffington Post:
"Frankly, it’s easy to suggest that basic research, the kind that’s done for curiosity rather than to spawn a product, should take a back seat to immediate needs. I still recall the schoolboy in Australia who wanted to know why, with people starving in the world’s baleful backwaters, the U.S. was spending hundreds of millions of dollars on 'motorized skateboards sent to Mars.' From his point of view, they did little more than paw at the dirt and make some nice photos."
When measured against the current atrocities that are occurring in the world, the ethics of funding astronomy projects are sketchy at best.
Then again, discovering other intelligent life isn't an obscure cause. "For the price of a few miles of freeway," says Dr. Marchis of SETI, "the detection of an extraterrestrial signal could change our vision of the universe and the place of humanity."
With the newly calculated Kepler Mission data, and ATA's radio antennas aching to be turned back on, the possibility of picking up a signal has never been greater. Someone just has to pay the phone bill.
Donations for turning the Allen Telescope Array back online can be made at seti.org
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