On a related note, the number put forth by the study (at least one planet per star, on average) is roughly consistent with Drake's 1961 estimate that half of all stars will have planets, and stars with planets will have 2 planets capable of developing life.
Except, of course, that Drake estimated an average of >=1 habitable planets per star. Still, it's good to see one of his estimates being corroborated.
Drake did no such thing. The Drake equation was not designed to give us an answer as to the number of civilisations out there, but to show us which questions needed to be answered to help us identify candidate search locations.
As an example, the Kepler mission is a direct result of the Drake equation, designed to resolve the first two parameters - fp and ne.
On a related note, the number put forth by the study (at least one planet per star, on average) is roughly consistent with Drake's 1961 estimate that half of all stars will have planets, and stars with planets will have 2 planets capable of developing life.
Except, of course, that Drake estimated an average of >=1 habitable planets per star. Still, it's good to see one of his estimates being corroborated.
http://en.wikipedia.org/wiki/Drake_equation