The Search for Intelligent Alien Life

In the year 1977, the National Aeronautical Space Agency (NASA) broadcasted messages coined in diverse languages into the universe with the Voyager spaceship. This necessitates the question of, who were these messages sent to?
Space Antenna


Does any alien life form exist outside our planet? Are they intelligent and possess a more sophisticated civilization? If indeed there are living beings that exist on the edges of our galaxy, can’t they also exist in the rest of the universe? The majority of scientists express the opinion that aliens may indeed exist.

If there are indeed other planets with advanced civilizations that utilize any form of technology, it is safe to assume that they also have the ability to transmit radio waves through space, the same way we do. The snapshot below is taken from outside the earth’s atmosphere and shows how the planet is seen from the outside by any alien life-form if they do exist. Radio waves have the capacity to pass through our planet’s atmosphere. So if we had no satellites, the signals broadcasted from our radios, phones and TV’s would still travel through space.

Space Junk

European Space Agency (ESA) – Space junk in our atmosphere.

Radio astronomy started in the 1930’s when an antenna used for wireless communication and designed by Bell Laboratories, by coincidence recorded a radio signal traveling through space. It was advocated that the radio signal was sent from the very center of our galaxy. Subsequently, the radio telescopes were developed to be our eyes in the universe, and this led to the detection of the evidence of the Big Bang Theory, i.e. Cosmic microwave background.

How we can communicate with extra-terrestrials?

When the “quest for extraterrestrials” commenced in the 60s and 70, the first question that we asked was: Supposing that aliens exist, how could they communicate with our planet? The best answer was in the form of waves, to be precise radio waves. But then again, radio waves had frequencies ranging from 3 kHz to 300 GHz. What frequency would we need to concentrate on?

Electromagnetic Spectrum

Electromagnetic Spectrum

The response to that question was simple. It was presumed that if the aliens were indeed intelligent beings, they would have recorded or possessed information on the human life and if that were so, they would pick a frequency that could move through our planet’s atmosphere. And that frequency is that of water. So we had our answer. This range of frequency is referred to as water-hole and because it has the lowest background noise, it is very easy to detect from our planet. And once we concentrated on this frequency, we received a signal. In 1977, the Big Ear radio telescope stationed at Ohio State University received a short-term signal from that frequency. Although searches were carried out to detect a repeat signal, it was all for nothing.

Do habitable planets exist in the Cosmos?

After the Kepler Telescope had been sent into space, the search for alien life was transformed into a hunt for livable planets. The justification for launching a telescope into space was apparent. It was done to capture signals that couldn’t enter our planet and also eradicate the background noise generated by our high-tech technologies. The Kepler telescope continually searches for an inhabitable planet like the planet Earth and does this by observing all the planet-star systems like our very own Solar System. As at February of 2017, the Kepler telescope has detected over 2,300 habitable planets with regards to temperature.

Up till now, intelligent life-forms outside the Earth have not been found, but the search continues. Even if no alien life-forms are found, by continuing the search, we can at least locate other planets that can be used as an alternative to Earth.