Since the early 20th century, mankind has communicated massive amounts of data through wireless transmissions. Radio programs, television shows, military radar signals have all traveled across the globe.
But those signals don’t stop at our atmosphere. Boundless, they travel out into the universe at the speed of light.
Meaning, theoretically, that Plutonian squid monsters could be watching our old reruns of “Two and a Half Men.”
But it works both ways. Working on the assumption that any advanced civilization will inevitably develop radio technology, scientists with the search for extraterrestrial intelligence (SETI) have been combing the skies, looking for signs.
"A unique aspect for the search of life in the universe is the question of whether advanced life evolves intelligence," Andrew Siemion, with the Netherlands Institute for Radio Astronomy, said during the Astrobiology Science Conference in June.
"The only way to answer that in the foreseeable future is to look directly for evidence," he added. "For that, you need a large telescope."
And a large telescope is exactly what SETI researchers are about to get. With plans for construction in both Australia and South Africa, the Square Kilometer Array (SKA) has been funded by a number of different countries and will be comprised of thousands of small antennae.
Massive radio telescopes already exist for such purposes. The Arecibo Observatory in Puerto Rico, for example, is the world’s largest, stretching 1,000 feet across the jungle. In addition to SETI research, it’s used for a number of purposes, including atmospheric science, radar astronomy.
A group of international financial terrorists even use the observatory to control an electromagnetic pulse satellite in 1995’s "Goldeneye." In real life, however, the dish is not camouflaged by an artificial lake. Sorry.
While the SKA would be composed of thousands of small antennae, taken as a whole, they would be significantly larger than the Arecibo Observatory. This will allow scientists to detect even fainter signals.
How faint? In theory, SKA could pick up a signal equivalent to an aircraft’s radar within a range of 200 light-years.
A Galactic Goose Chase?
While many are excited about SKA’s prospects, the project isn’t without criticism.
For one, some are skeptical about the idea of spending such vast amounts of money on a telescope intended for only one purpose, especially since that purpose has no guarantee of succeeding. If we truly are alone, it seems wasteful to endlessly pump billions into a program that looks for signs it will simply never find.
We’ve been searching for 30 years, after all, with little to show for it.
But there’s also another problem. If we look at humanity as a model – and really, what other alternative do we have – radio wave technology is little more than a century old and is already being phased out in favor of new, digital technology. Aliens may enjoy old episodes of "The Honeymooners" from network television, but they’re going to have a harder time picking up the latest season of "True Detective" – not that they’re missing much.
If alien civilizations follow a similar trajectory, then artificially created radio waves could have a relatively minor presence in the universe.
Still, that’s not deterring SETI researchers. While SKA will certainly search for the kind of random signals which would emanate from alien broadcasts, they’re also hoping to detect something a little more focused: transplanetary communications.
It’s possible that if extraterrestrial societies exist that would spread beyond their host planet. Just as NASA is developing plans to colonize Mars, distant civilizations could also spread throughout their own solar system. In that event, the best way to communicate between planets would still be via wireless radio waves.
Intentionally focused out into space, those waves would be even easier to detect, especially for an instrument as sensitive as SKA.
It’s certainly possible that the search for extraterrestrial intelligence will never bear fruit. It’s hard to imagine that we’re alone in the massive depths of the universe, but until we find at least one other instance of life, we don’t really have enough data to make any estimates. It’s also possible that even if life exists elsewhere, it may not overlap with our own.
In the thirty years of scanning the stars, have scientists found any promising signs? One.
In 1977, a scientist working with the Big Ear radio telescope at Ohio State University caught a strange signal emanating from the constellation Sagittarius. Lasting 72 seconds, the signal bore all the signs of having a non-traditional, none-Solar System origin. It’s now commonly referred to as the "Wow! Signal," as it surprised its discoverer so much that he circled the data on a printout, writing "Wow!" in the margins.
Despite many attempts, that signal has never been detected since, and scientists still have no explanation for it.