Drake Equation

Advanced Aerospace Weapons Systems Application Program: UAPTF / AATIP programs

$N = R^{\ast} \times f_p \times n_e \times f_{\ell} \times f_i \times f_c \times L \!$

where:

N is the number of civilizations in our galaxy with which communication might be possible;

R^* is the average rate of star formation in our galaxy

f_p is the fraction of those stars that have planets

n_e is the average number of planets that can potentially support life per star that has planets

f_ℓ is the fraction of the above that actually go on to develop life at some point

f_i is the fraction of the above that actually go on to develop intelligent life

f_c is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L is the length of time such civilizations release detectable signals into space.

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Project: Ozma
Code: Green Bank
Directive: Estimate number of extraterrestrial civilizations we may potentially come into contact with.
Teams:

• Chien-Shiung Wu
• Frank Drake
  

Date: 1956 to 1960

References

Resources

• The Principles of Psychology (1890)
• Lee, T. D.; Yang, C. N. (October 1, 1956). "Question of Parity Conservation in Weak Interactions". Physical Review. 104 (1): 254. Bibcode:1956PhRv..104..254L.
• http://www.astrodigital.org/astronomy/drake_equation.html