Why Is A Search For Extraterrestrial Life Necessary?

Photo by Miriam Espacio on Unsplash

Humans are a unique and interesting living thing on earth. Humans are always curious to learn about everything which they don’t know. Since the day when the first human was born, they have always wanted to seek the answers to all the things which are around them. When it comes to space they always try to explore it according to a research we’ve explored 4 percent of the visible space until now.

According to a 2013 study there were about 225 billions of galaxies which increases with the passage of time. Like when scientists studied in 2016 again they found that the galaxy had increased to 2 trillion in numbers. According to a study there are about 800 billions to 3.2 trillion planets in our Milky Way galaxy. Just think of how big the universe is.

So here’s a question: are we alone in this universe? Do aliens exist? If Aliens exist, what do they look like? Do Nasa or Spacex have any missions for finding aliens? Almost every human on earth wants to know the answers to these questions. Today we will be discussing and trying to get answers to all these interesting questions in this article.

Do Aliens Exist?

Here we come to the very common and frequently asked question. Before discussing the answer of this question we need to know what aliens are? This is the simple definition of aliens “Creatures which exist outside the Earth are called aliens or extraterrestrial life”. Now coming to our answer, scientists have no proof that aliens had landed into our planet in the past or that they even exist. But scientists are suspicious that we may find intelligent life somewhere in a planet or other galaxy. Some scientists now believe that we are just a few years away from the first Alien contact.

Unsplash Stephen Leonardi

There are billions of galaxies in our universe that may have intelligent life. We haven’t discovered other galaxies because they are millions of light-years away. You may ask, how far is one light year? Let me tell you, One light-year is equivalent to the distance in which light travels in one year. Humans will take under 20,000 years in order to travel one light year. We would need the speed of light in order to travel to other galaxies.

Suppose if we achieved the speed of light we will be able to go around the earth 7.5 times in one second, but unfortunately Einstein’s theory of relativity says it is not possible for a living thing or matter to travel at the speed of light. Scientists and astronauts say If we send a signal today to other galaxies then it will take about 100 years to reach there. Similarly if we receive any signal today, it would’ve been sent 100 years before, So we will not be sure if they still exists. Scientists have discovered approximately 4000 exoplanets. So what are exoplanets? We will be discussing it in detail ahead, let’s take a look.

What Are Exoplanets?

Credit: Nasa

The very simple definition of an exoplanet is that “The Planets which revolve around another star are called exoplanets”. They’re rocky planets having a mass equivalent to the mass of Earth or Mars. The closest exoplanet to our solar system which has been discovered until now is Proxima Centauri b which has a mass of 1.27 earth masses and revolves around a star named Proxima Centauri. They were discovered in 2016. Proxima Centauri b takes 11.2 days to complete one orbit around its star.

The very first earth-size exoplanet named Kepler-186f was discovered on 23 July 2015 by Nasa’s Kepler mission which lies in the habitable zone and revolves around a red dwarf named Kepler-186. So what is a habitable zone and what is a red dwarf ? A habitable zone is the distance of a planet from the star which can have liquid water on its surface, while a red dwarf is a very cool star. The exoplanet is 40 percent larger than earth and resides 500 Light-years away from the earth. Do you know there is a research organization who seeks for intelligent life? If not then let me tell you ahead.

SETI Institute

The abbreviation of SETI is Search for Extraterrestrial Intelligence which was discovered in 1984 in California. The institute was founded by Thomas Pierson (former CEO) and Dr. Jill Tarter as a non-profit organization. The aim of this organization is to look and find intelligent life in the Universe.

Do you know what constellations are ? If not, no worries, A constellation is the group of visible stars which you see at night that makes a pattern representing animal, person or any other object. There are 88 constellations throughout the universe. There was a radio astronomer named Frank.D Drake who began the Ozma project which was a project of SETI in 1960 intending to detect or communicate intelligent life. It was the first time humans attempted to detect interstellar radio transmissions.

Drake chose Tau Ceti (a star similar to the sun) in the constellation Cetus (the whale) and Epsilon Eridani (Star) in the constellation Eridanus (the river) which are eleven light-years (66 trillion miles) away. Our sun is around the same age as both of these stars. Frank.D Drake determined that the Green Bank Telescope (A steerable radio telescope) can detect radio transmissions coming from up to 10 light-years away.

Credit: pngwing.com

The Green Bank Telescope was tuned to the 21 centimeter emission (1420 MHz) coming from cold hydrogen gas in interstellar space for six hours a day for 3 months i-e from April to July 1960. The project was ended as the signal received by the Green Bank Telescope were the hydrogen radiations emitted from the star. Next in the article you’ll know about how many sources we have for communication in the space.

Unusual Signal

On august 15, 1977, some scientists received an unusual signal which was coming from the direction of the constellation Sagittarius. The signal was received for 72 seconds by the Ohio State University’s Big Ear Radio Telescope and after that it spontaneously faded away. Jerry R. Ehman who is an american astronomer and the one who intercepted this signal. The signal was so odd that Jerry Ehman scrawled “Wow!” Since that day it is renowned in this name.

There’s no such pinpoint interpretation of that signal but there are a lot of opinions about that signal. Some scientists argue that the frequency of the wow signal was 1420.4556±0.005 MHz and it is similar to the frequency of hydrogen which is 1,420,405,752 Hz, which means that these signals were hydrogen radiations.

Source of Communication

Do you know who invented long distance radio transmission? If no then let me tell you, thanks to Guglielmo Marconi who was an Italian electrical engineer who invented long-distance radio transmission. In 1894, the first long distance radio transmissions were made which traveled through space at the speed of light for a century. This signal crossed Sirius (brightest star) in the constellation Canis Major, Vega (brightest star) in the constellation Lyra, and Regulus (brightest star) in the constellation Leo in 1903, 1919, and 1971, respectively.

The signal has already traveled through 1000 stars. Marconi’s signal could have been detected by someone circling one of those stars with a good receiver and could’ve been known that we’re here. Radio waves are the longest and contain the least energy of an electromagnetic wave.

Arecibo Radio Telescope

You all might be familiar with Heinrich Hertz, the one who discovered radio waves in 1888. The first commercial on the radio station went on air in Pittsburgh, Pennsylvania, US on November 2, 1920. Subsequently in 1932, Karl Jansky who was an American physicist and radio engineer revealed that stars and other objects in space radiate radio waves and Radio Astronomy was born. However, scientists need giant antennas to detect weak and long-wavelength radio waves from space.

Radio waves play an important role in most of the important astronomical discoveries. Radio waves were used to discover pulsars (a compact star that emits beams of electromagnetic radiation out of its magnetic poles), massive clouds of super heated plasma, and even quasars (highly luminous which can be found in the centre of some galaxies and gases spirales at high velocity into an extremely large black hole), which are among the largest structures in the Universe.

Heavenly bodies that have a magnetic field usually produce radio waves such as our sun. You may be familiar with the big Arecibo radio telescope which is 305 meters in diameter, and occupies a land equals to three football fields. Arecibo was the largest radio telescope on earth until December 1, 2020. Unfortunately Arecibo Observatory’s 900 ton instrument platform collided with its dish, which was cradled in a natural sinkhole. Arecibo had been in the service for 53 years. Arecibo was surpassed by a Chinese radio telescope named Five-hundred-meter Aperture Spherical Telescope (Fast) in July 2016.

FAST Telescope


We always want to search or explore a planet where life can be possible. We are advanced enough to find, visit new planets and discover new intelligent beings like ourselves or more advanced than us. At least one time in your mind the question may have risen that why are humans eagerly willing and impatient to see extraterrestrial life? The answer is very simple, if we find any extraterrestrial intelligence we’ll collaborate and will be able to explore the universe and humans will be 5x 10x more advanced than from now. What is the assurance that they will help us and not attack? There are a lot of arguments between scientists about it but we don’t know yet if we find them what will happen.

There are always 6 to 25 scientists in space every time to explore planets and extraterrestrial Intelligence. Maybe like Earth after 11 billion years or even more time another planet evolves and forms some kind of living thing like human.




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Wasif Khan

Wasif Khan

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