In the vast expanse of the cosmos, the earth is but a miniscule speck. There could be as many as 160 billion planets in our galaxy, says one statistical study. On this huge canvas, is earth the only chosen planet to host intelligent life?
It is highly probable that we are not alone in the universe and the chances of advanced civilisations existing out there are rife. Over the centuries, humans have been curious about aliens, and in their quest, gazed through their telescopes in hope.
In the 1950s, eminent scientist Enrico Fermi proposed that according to calculations it would take only a few tens of millions of years for an advanced civilisation to colonise our galaxy. So far, such a situation has not occurred despite the galaxy being thrice as old as the earth. At a conference, Fermi threw a tantalising question to the scientific fraternity: “Where is everybody?” prompting numerous speculations about other civilisations, leading to the famous Fermi Paradox.
In 1960, American astrophysicist Frank Drake came up with a mathematical calculation to estimate the possibility of the number of intelligent societies that could be existing out there. Known as the Drake equation, his conjectural analysis predicted that there could be anywhere from 20 to 50 million civilisations living in our galaxy.
The search for extra-terrestrial intelligence has intensified in the past few decades, with the support of space missions and dedicated telescopic probes in space, giving a better and closer look at other planets and habitable worlds. The TRAPPIST system is one such example.
However, so far, we have not come across any alien life form nor have we received any communications sent by them. So, where are they? Why have we not seen an alien race leave their footprints so far? Alternatively, are they attempting to communicate with us and we are not advanced enough to interpret their signals? Could it be that we are yet evolutionary juveniles and hence they are keeping to themselves? Else, will they, one day, merely descend upon us? The puzzle still plagues astronomers.
Watch out for the skies
Throughout history, sporadic events and sightings of alien craft have been reported, which were later debunked as no concrete evidence of extraterrestrial signatures was found. However, there is much mystery, gossip and guesswork that shrouds the events; it is also thought that sightings are kept under wraps to avoid chaos and confusion, until investigations yield concrete results.
Meanwhile, efforts to communicate and receive signals continue.
SETI — Search for Extra-Terrestrial Intelligence — is a non-profit organisation founded in 1984, whose mission is to address some of the above mysteries. The institute collaborates with Nasa, the National Science Foundation and various international space agencies to monitor and interpret radio signals from outer space and is the authorised facility to track and read signs from space.
With rigorous research projects, SETI is deploying all-the-time global observatories to detect signals from outer space. SETI is also actively involved in all the major space missions: by providing plaques with coded messages which can be understood by intelligent lifeforms, should they intercept it.
Are we streaming any messages? Yes. In 1974, Frank Drake developed a digitised code depicting some essential aspects of the earth and beamed it at a star M13 — around 20000 light years away— using a powerful transmitter. Called the Arecibo Message, it was an intendedly demonstrative message. However, over the years, Drake has supervised many changes to it. The scientists in this project are working to develop a perfect, concise and informative message about the earth — to whoever finds the signal.
Parallelly keeping an ear to the skies, giant radio receivers across the globe are listening incessantly for any form of a signal that could lay hidden in the cosmos.
While the science community grapples with the unsolved puzzle, we too, as denizens of the cosmos have a role to play in this quest and watch the skies for unidentified flying objects (UFO). In fact, July 2 offers a chance to do so: declared as World UFO Day, it provides a platform for people to gaze at the skies and is also an appeal to governments to declassify their files of UFO sightings.
While the extra-terrestrial conundrum prevails, we can take this opportunity to create an awareness of the undoubted existence of alien civilisations, for, should the visitors choose our rooftop or backyard and surprise us, shouldn’t we be prepared?