<P> The Drake equation is a probabilistic argument used to estimate the number of active , communicative extraterrestrial civilizations in the Milky Way galaxy . </P>
<P> The Drake equation is a probabilistic argument used to estimate the number of active , communicative extraterrestrial civilizations in the Milky Way galaxy . </P>
the drake equation is used to predict the number of
the drake equation is used to predict the number of
active , communicative extraterrestrial civilizations in the Milky Way galaxy
active , communicative extraterrestrial civilizations in the Milky Way galaxy