Do enigmatic creatures like ‘E.T.’ and ‘Jadoo’ shown in Hollywood and Bollywood movies actually exist? How are we going to find that out in real life? Is there an organization that is involved in searching for extraterrestrial life? If yes, who are the people working with it? SETI is the answer to these mind boggling questions.
What does SETI stand for?
SETI stands for ‘search for extraterrestrial intelligence’.
Project SETI began actively in 1960 when an American astronomer Frank Drake started searching for radio signals from two stars near Earth.
SETI is based at the University of California and the purpose of this project is to use radio telescopes from around the world to scan the sky to look for special patterns in radio waves that could have been sent by some alien civilization in space.
There is a huge radio telescope installed at Arecibo, Puerto Rico that catches all the radio signals floating around in the space. This telescope has a huge bowl-shaped dish which is almost 1000 feet in diameter and takes pride in being the world’s largest stationary radio telescope.
The researchers analyze thousands of radio signals intercepted through this telescope daily. Currently, astronomers are building an Allen Array Telescope which would be able to check much more stars and the planets orbiting around them with higher precision.
Scientists prefer to use radio telescopes because radio waves can reach very far in space without being absorbed by the thick clouds of gas and dust that are extensively found in the space. Radio telescopes can be used both day and night and radio signals are easy to detect as compared to other forms of signals and signs.
However, in the last few decades, astronomers are also contemplating the use of optical signals to search for extraterrestrial intelligence. Scientists are busy developing powerful lasers—devices that will emit strong optical signals in space and could act like cosmic projectors.
Since 1998, astronomers in Harvard University have been keenly looking to intercept pulse optical signals. The Planetary Society (Headquarters in Pasadena, California) also surveys the sky for optical extraterrestrial signals using a large telescope.
Sending messages to the other stars is somewhat like sending a message in a bottle from a faraway marooned island in the hope that someday someone out there on the shore will find it.
It is this hope that keeps the stranded person alive and it is this hope again that keeps the scientists going. Actually, astronomers did send a message in 1974 to the globular cluster M13 which consists of about million stars.
Has it been received by some alien civilization or is yet to be received? If received, have the aliens been able to understand it? Well, these are the questions that no one can answer as yet.
One of the major problems that the scientists encounter is the huge distance between Earth and the other stars.
Even if we target the stars that are closest to us, our message would take nothing less than 40 years to reach the target location and if the target is far away from us, then the number of years taken would be in thousands. These problems have so far not deterred our scientists and they are leaving no stone unturned in informing the extraterrestrial civilizations about our planet.
Certain spacecrafts like Pioneer 10 and 11, Voyager 1 and 2 carry a record with information about Earth and the achievements of the human civilization.
This has been done keeping in mind that if the aliens do happen to come across these spacecrafts, they are able to access detailed and more importantly, accurate information about our planet easily.
These spacecraft are all currently headed out of the solar system in search of finding any clue about aliens.
The basic idea for establishing SETI is to exchange correct and unambiguous information in order to establish friendly relations with our fellow dwellers of the universe. Of course we don’t want to face a situation like that shown in Hollywood’s famous movie “Mars Attack”, do we?
Scientists are also contemplating planting a large radio telescope on the Moon. It would then be easy for them to distinguish the registered signals from those of Earth’s technological origin.
They will also be able to register the signals with all possible radio waves because there is no atmosphere on the Moon.
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