Drake's Equation - What is the probability of finding Extraterrestrial Life in our Galaxy

The Drake Equation was the first mathematical formulation accepted by the scientific community to estimate the number of civilizations in our galaxy, the Milky Way, in other words, to determine the existence or not of intelligent life outside our planet.

The Drake Equation identifies specific factors believed to play an important role in the development of civilizations. Although there is currently not enough data to solve the equation, the scientific community has accepted its relevance as a first theoretical approach to the problem, and several scientists have used it as a tool to raise different hypotheses.

The Drake Equation represents a theoretical approach to take into account about one of the recurrent doubts of the human mind.

Are we the only inhabitants of the Universe?

Considering that in the Milky Way there can be counted between 200 and 400 million stars, around which planets orbit, the Drake Equation proposes that up to 10 civilizations in our galaxy would have intelligent life and would be able to communicate with us.

Radio astronomer and SETI president Frank Drake formulated the Equation in 1961 while working at the National Radio Astronomy Observatory in Green Bank, West Virginia, USA, to calculate the probability that another civilization could communicate with us.

Our Sun is just a lone star out of the abundance of 7 × 1022 stars in the observable universe. The Milky Way is only one of the 2,000,000,000,000 Galaxies estimated to exist in our Universe. It would seem then that there should be fullness of life out there.

His calculations yielded a result of 0.00000003%. It seems like a slim possibility, but the fact is that Drake was criticized for throwing an overly optimistic estimate.

Drake's formula is as follows: 

N = R * fp ne fl fi fi fc L 

-N is the number of civilizations that could communicate with us.

-R* is the total number of stars capable of hosting planets.

-fp corresponds to the number of those stars that have planetary systems.

-ne represents the average number of planets with the possibility of life that would exist in those systems.

-fi includes the number of planets on which intelligent life actually develops.

-fc discovers the number of planets with intelligent life and that, in addition, could communicate with others.

-L refers to the time of life of the planet in which that civilization develops.

So sure was Fran Drake of the results of his equation that he was one of the promoters of the SETI Institute that has been waiting for more than five decades for an extraterrestrial response.

However, it is currently almost impossible to pin down some factors in his formula, such as the number of planets that could host intelligent life or, one-step further, how many of them would have the appropriate technology to communicate with Earth.

Although mathematically well formulated, the Drake equation may never give us a reliable result about whether we are alone or not.

According to the latest data from NASA and the European Space Agency, the galactic production rate is seven stars per year. On the understanding that stars type K and G are suitable and if of the total of stars 12.1% are stars of type K and 7.6% are stars type G like the Sun, then only 19.7% of those seven stars that are born each year are auspicious, therefore only 1,379 of those seven annual stars are truly fit to possess life.

Modern researchers from the European Southern Observatory dedicated to the search for planets argue that approximately one in three stars of type G could contain planets. The percentage of planets in orange stars or red dwarfs are not counted in the estimate.

Due to the lack of evidence, as technology evolves, many parameters of the equation could vary markedly.