Ever wondered if life exists on planets other than earth?

Is there life on other planets

Scientists and astronomers are constantly on the search for extraterrestrial life(life on other planets that does not originate from earth). Even though there is no direct evidence of presence of life on other planets yet, since the mid-20th century, there has been ongoing search for signs of extraterrestrial life, from radios used to detect possible extraterrestrial signals, to telescopes used to search for potentially habitable extrasolar planets.

However there are several reasons that suggests the existence of life on other planets. Alien life can exist on other planets because the universe is so vast that there is a huge chance that there are planets that have atmospheric conditions similar to earth, even though conditions similar to earth is not a prerequisite for life. Life is known to evolve and survive in places that have conditions radically different from the normal atmospheric conditions like the Chernobyl fungus which can withstand extreme doses of radiation and the Pompeii Worm which can withstand high temperatures.

According to one hypothesis life on earth is thought to have originated as a result of chemical reactions that lead to the formation of  cellular membranes and proto-DNA, thus forming life. Life on earth requires water as the solvent in which biochemical reactions take place. Sufficient quantities of carbon and the other elements along with water, may enable the formation of living organisms on other planets with a chemical make-up and temperature range similar to that of Earth. The combination of carbon, hydrogen and oxygen in the chemical form of carbohydrates (e.g. sugar) can be a source of chemical energy on which life depends, and can provide structural elements for life

In 1961 astronomer and astrophysicist Dr. Frank Drake devised the Drake equation. This controversial equation multiplied estimates of the several terms to find life-supporting planetary systems in the observable Universe. There are at least 125 billion galaxies in the observable Universe. It is estimated that at least ten percent of all sun-like stars have a system of planets. Even if we assume that only one out of a billion of these stars have planets supporting life, there would be some 6.25×109 (billion) life-supporting planetary systems in the observable Universe. Criticism of the Drake equation follows mostly from the observation that the terms in the equation are entirely based on conjecture.

Although there may be other planets that have life supporting conditions, so far scientists have not found any that supports life. Earth remains the only one as of now.