Today, extraterrestrial life is so sensationalized that at times it is very hard to identify what is truly evidence or just made up fictional stories. Does extraterrestrial life really exist? Let us study the following two theories regarding this life’s existence.
The Panspermia Theory
The Panspermia theory states that life exists throughout the universe in the form of similar spores. These spores or life seeds originate in space and then that life is seeded onto various planets. This theory originated with the hypothesis of a Greek philosopher; however, it was later conceptualized by Sir Fred Hoyle, a British astronomer.
Scientists search for these spores in other heavenly bodies by examining meteors landing on Earth and by outer space missions. Mars has shown a sign of bacterial life, through fossilized remains discovered on the planet. These fossilized remains are believed to be bacteria, which would be essential for living. Some scientists do dispute these fossils as evidence of bacteria life.
In cases where the temperature of a planet cools down – similar to what happened to Earth – then the temperature change could possibly create a habitat capable of sustaining life. If this theory is correct, then life can eventually be supported by all of the planets. Furthermore, it may also indicate that life may not have originated on Earth itself.
Other scientists also claim that the Earth wasn’t originally fit for sustaining life, that it is possible that the life source came from somewhere else. According to Lord Kevin, life on Earth originally came from Mars when a meteorite from the planet landed on earth. This theory holds the potential for truth provided that before the Earth’s atmosphere cooled, life was already present in a nearby heavenly body.
Though many still believe that life didn’t begin on Earth, the opposite is more generally accepted. Nonetheless, the unanswered questions on the development of intelligence and other complex functions of the body may reinforce the preceding belief.
The only thing that is certain is that life on Earth originated within the solar system. If life was brought here from another system, then the first inhabitants of Earth should have possessed more complex cellular formations. Thus, we may not have looked the way we are now due to cell evolution.
With regard to cell evolutions, experiments reveal that bacteria can survive for a long time even in space. Studies in India have discovered bacteria that thrive high above in the Earth’s atmosphere. These bacteria survive by merging with those found in the lower atmosphere. An example of this activity is that bacteria brought from the moon in 1967 were revived here on Earth in 1970.
The downfall of Panspermia theory is that all living organisms in and outside the Earth must have the same biochemistry. There is no way this can be proven unless an extraterrestrial being was found and could actually be studied.
The Drake Equation
Aside from the belief about a certain life spore in the Panspermia theory, some experts also insist that if life exists on Earth, then given the vastness of the universe there should no longer be any question that life exists outside Earth.
In the 1960’s, Frank Drake devised an equation to calculate the probability that extraterrestrial beings exist. It may have been a good formulation, but the variables in Drake’s equation are still questionable and don’t corroborate with other proven studies on the heavenly bodies.
These discrepancies are called the Fermi Paradox named after Enrico Fermi. According to this theory, there is not enough proof to support the values of the variables, and some of these numbers are obviously leaning on proving extraterrestrial existence.
There are many accounts of people as well as other proofs such as videos and pictures imparting that aliens and other extraterrestrial beings exist. Nonetheless, as the above theories have been disputed by merely a few inexplicable areas, the proofs we see now also remain questionable.
If you believe in the supernatural, which is beyond the scope of science, then perhaps you can assume that aliens truly exist. However, without support from the mainstream scientific community, we cannot consider extraterrestrial life a fact.