Drake Equation Calculator Website The Drake equation is a mathematical formula used to estimate the number of detectable extraterrestrial civilizations in our galaxy.
The equation was first proposed by astrophysicist Frank Drake in 1961 as a way to organize the various factors that could influence the likelihood of the existence of extraterrestrial life.
N = the number of civilizations in the Milky Way galaxy with which communication might be possible
R = the average rate of star formation in our Galaxy
fp = the fraction of those stars that have planets
ne = the number of planets per star that are in the "habitable zone" (where conditions are right for liquid water to exist)
fl = the fraction of those planets on which life develops
fi = the fraction of those planets on which intelligent life develops
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space