Frank Drake in 1961 tackled a most puzzling question:
Does there exists any intelligent extra-terrestrial life in our Milky Way galaxy?
Drake came up with a method to estimate how many alien civilizations can actually communicate with us. It is known as the Drake Equation and it multiplies together 7 numbers. Each number is denoted by a symbol.
- R* = the rate of star formation, that is how many new stars are formed each year in our Milky Way
- fp = the fraction of stars that have planets
- nc = the average number of planets that can support life
- fl = the fraction of planets that actually develop life
- fi = the fraction of planets with life that have intelligent life
- fc = the fraction of intelligent life that can communicate with us
- L = the expected lifetime of the civilization
Multiply all these numbers together, you will have a prediction of the number of alien civilization in our galaxy that can communicate with us.
Try putting in some numbers in the Drake Equation Calculator and see what you predict for the number of alien civilizations.