Just what are the chances that intelligent life-forms exist on other
planets and how are we looking for them?
Is there a formula which calculates the probability of their
See "Alien Contact" at The WHY? Files,
Some useful articles and essays relating to the exploration and
understanding of the origin, nature and prevalence of life in the
Articles and essays relating to the existence of alien life forms.
The Drake Equation
A brief history of Frank Drake and the formulation of The Drake
Predator And Prey Models And Contact Considerations by Douglas