Exoplanets and the Hunt for Extraterrestrial Life

Exoplanets and the Hunt for Extraterrestrial Life

Till 1910s scientists believed that the nearby stars are all part of a vast collection of stars called the Milky Way galaxy and this was the whole universe. It was only till 1924 when an American astronomer named Edwin Hubble figured out that the Milky Way was not the only galaxy in the universe, but one of thousands and thousands of other galaxies with large space between them.

Just like that it was believed there are no planets outside the Solar System.

The first evidence of an exoplanet or a planet outside the Solar System was noted in 1917 but was not taken seriously. The first confirmation was in the year 1992 followed by confirmation of another exoplanet in 1988.

Exoplanet Kepler-186f (Source: Wikimedia Commons)

In the recent decades, scientists have developed a major interest in exoplanets to find extraterrestrial life. There are many earth like planets which scientists are observing. So far about 5000 exoplanets have been found and most of the are less than 3000 light years away from earth.

In the last century, astronomer Harlow Shapley estimated that there are about 10²⁰ stars visible using advanced telescopes. If we speculate that every one thousandth star has the necessary conditions for life, then the calculation still gives 10¹⁴ stars. And assuming that every one thousandth star may have prerequisites for life, that still gives a massive figure of 10¹¹. If we calculate even further and conclude that every one thousandth planet of this figure could have produced life, that will still give 10⁸ planets with life. According to the hypothesis of biochemist Dr. Stanley Miller, there could be planets with life developed quicker than here on earth. If we accept this, there could be thousands of planets with more developed civilization than us.

Alien Civilization Concept Art

People usually believe that water and oxygen are the main requirements for life on a planet. But this is a mistake. Ever here on earth, there are many bacteria that do not need oxygen for survival, and these are called anaerobic bacteria. A given amount of oxygen acts as a poison to them. There was an experiment carried out by Dr. Stanford Siegel in which he recreated the atmospheric conditions of Jupiter in his laboratory and bred bacteria and mites there and ammonia and methane did not kill them. There was another experiment in which two entomologists of Bristol University kept midges in extremely high temperature and then later dipped them in liquid helium which is as cold as space. When these midges were kept back to their normal living conditions. Later, these midges carried out their important biological functions and produced perfectly healthy midges. These are not just mere experiments, but important evidence that tells life can be produced on any planet throughout the universe.