Published on Jun 05, 2023
DRAKE EQUATION
N = R * x f p x n e x f l x f i x f c x L
The terms in the equation can be explained as follows
. N - Number of communicative civilizations
. R* - Average rate of formation of stars over the lifetime of the galaxy (10 to 40 per year)
. fp - Fraction of those stars with planets (0 < fp <1, estimated at 0.5 or 50 percent)
. ne - Average number of earth-type planets per planetary system (0 < ne <1, estimated at 0.5 or 50 percent)
. fl - Fraction of those planets where life develops (0 < fl <1, estimated at 1 or 100 percent)
. fi - Fraction of life that develops intelligence (0 < fi <1, estimated at 0.1 or 10 percent)
. fc - Fraction of planets where intelligent life develops technology such as radio (0 < fc <1, estimated at 0.1or 10 percent)
. L - Lifetime of the communicative civilization in years (estimates are highly variable, from 100s to 1000s of years, approximately 500 years for example purposes)
BASIC PROBLEMS IN SEARCH
" How to search such a large area of sky
" Where to look on the radio dial for ET
" How to make the best use of the limited radio-telescope resources available for SETI
