The Drake Equation

In 1961, Frank Drake, then an astronomer at the National Radio Astronomy Observatory, in Green Bank, W.Va., first posited this equation as a way to think about the various factors affecting how many intelligent, communicating civilizations there are likely to be in our galaxy. The equation goes as follows:

N=N*f_p n_e f_l f_i f_c f_L

Where N* represents the number of stars in our galaxy,

f_p is the fraction of stars that have planets around them,

n_e is the number of planets per star capable of maintaining life,

f_l is the fraction of planets in ne where life evolves,

f_i is the fraction of fl that evolves intelligent life,

f_c is the fraction of fi that communicates, and

f_L is the fraction of the planet’s life during which the communicating civilization survives.

Thus, N is the number of communicating civilizations.