In 1961, the creation of an agenda for a meeting of radio astronomers birthed a now famous equation. But what does N = R∗ · fp · ne · fl · fi · fc · L actually mean? We crunch the numbers, talk space, movies and more on this episode of Beyond Terrestrial.

https://en.m.wikipedia.org/wiki/Drake_equation

http://www.astrobio.net/alien-life/the-drake-equation-revisited-part-i/

https://www.google.com/amp/s/www.space.com/amp/25219-drake-equation.html