There are many people including scientists who have a strong belief that we are not alone in this universe. However, we still await for some sort of strong evidence in the form of radio signals. But what if ET calls tomorrow? Are we prepared for the next step? An institute called SETI (Search for Extraterrestrial Intelligence) is one of the leading non-profit organisations whose mission is to “explore, understand and explain the origin, nature and prevalence of life in the universe”. Let us know more about SETI’s origins and does it have what it takes to break the eerie silence of space.
On a cold and misty morning in April 1960, a young astronomer named Frank Drake quietly took control of the 26-metre dish at the US National Radio Astronomy Observatory in Green Bank, West Virginia.
Few people understood that this moment was a turning point in science. Slowly and methodically Drake steered the giant instrument towards a sun-like star known as Tau Ceti, eleven light years away, tuned in to 1,420 MHz, and settled down to wait.
His fervent hope was that alien beings on a planet orbiting Tau Ceti might just be sending radio signals our way, and that his powerful radio dish would detect them. Drake stared at the pen and ink chart recording the antenna’s reception, its fitful spasms accompanied by a hiss from the audio feed. After about half an hour he concluded there was nothing of significance coming from Tau Ceti – just the usual radio static and natural background from space. Taking a deep breath, he carefully reoriented the big dish towards a second star, Epsilon Eridani.
SETI … seeks to answer one of the biggest of the big questions of existence: are we alone in the universe?
Suddenly, a series of dramatic booms emanated from the loudspeaker and the pen recorder began frantically flying back and forth. Drake almost fell off his chair. The antenna had clearly picked up a strong artificial signal. The astronomer was so taken aback he remained rooted to the spot for a long while.
Finally, getting his brain in gear, he moved the telescope slightly off target. The signal faded. But when he moved the antenna back, the signal had disappeared! Could this really have been a fleeting broadcast from ET? Drake quickly realized that picking up a signal from an alien civilization on the second attempt was too good to be true. The explanation must lie with a manmade source and, sure enough, the signal turned out to be produced by a secret military radar establishment.
With these humble beginnings – whimsically called Project Ozma after the mythical Land of Oz – Frank Drake pioneered the most ambitious, and potentially the most significant, research project in history. Known as SETI, for Search for Extraterrestrial Intelligence, it seeks to answer one of the biggest of the big questions of existence: are we alone in the universe?
..it is a needle-in-a-haystack search without any guarantee that a needle is even there.
Most of the SETI programme builds on Drake’s original concept of sweeping the skies with radio telescopes for any hint of a message from the stars. It is clearly a high-stakes endeavour. The consequences of success would be truly momentous, having a greater impact on humanity than the discoveries of Copernicus, Darwin and Einstein put together. But it is a needle-in-a-haystack search without any guarantee that a needle is even there. Apart from one or two intriguing incidents (of which, more later) all attempts have so far been greeted with an eerie silence.
What does that tell us? That there are no aliens? Or that we have been looking for the wrong thing in the wrong place at the wrong time?
SETI astronomers say the silence is no surprise: they simply haven’t looked hard enough for long enough. To date, the searches have scrutinized only a few thousand stars within 100 light years or so. Compare this to the scale of our galaxy as a whole – 400 billion stars spread over 100,000 light years of space. And there are billions of other galaxies.
But the power of the search is expanding all the time, following its own version of Moore’s Law for computers, doubling every year or two, driven by surging instrument efficiency and data-processing speed.
Now the scope is set to improve dramatically, with the construction of 350 interlinked radio dishes at Hat Creek in Northern California.
Named after the benefactor Paul Allen, the Allen Telescope Array will enable researchers to monitor a much larger fraction of the galaxy for alien signals.
The basic scenario was well enough portrayed in the Hollywood movie Contact, in which Jodie Foster plays the role of the lucky, overawed astronomer. What is far less clear is the next step. What would follow from the successful detection of an alien radio signal?
..by sending our own message to the aliens. Would that invite dire consequences, such as invasion by a fleet of well-armed starships?
Most scientists agree that such a discovery would be disruptive and transformative in myriad ways. Even contemplating a signal received out of the blue raises many questions: how and by whom would it be evaluated? How would the public get to learn about it? Would there be social unrest, even panic? What would governments do? How would the world’s leaders react? Would the news be regarded with fear or wonderment? And in the longer term, what would it mean for our society, our sense of identity, our science, technology and religions?
On top of these imponderables is the vexed issue of whether we should respond to the signal, by sending our own message to the aliens. Would that invite dire consequences, such as invasion by a fleet of well-armed starships? Or would it promise deliverance for a possibly stricken species? There are no agreed answers to any of these questions.
The narrative of the movie Contact parted company with established science once the signal was received, and lurched off into the speculative realms of wormhole space travel and other dramatic themes. That was science fiction, deriving from the fertile imagination of the late Cornell University astronomer Carl Sagan, author of the book on which the film was based. In the real world, it is completely unclear what would follow the discovery that we are not alone in the universe.
In 2001 the International Academy of Astronautics established a committee to address ‘what next?’ issues. Known as the SETI Post-Detection Taskgroup, its job is to prepare the ground in the event that SETI suddenly succeeds. The rationale is that once a signal from an alien source is confirmed, things would move too fast for the scientific community to deliberate wisely.
For the time being all we can do is wait, watch and hope that someday the eerie silence of space will be broken.