Carl Sagan Explains The Drake Equation

Someone posted the part of the Cosmos episode where Carl Sagan explained Frank Drake's equation for estimating the number of intelligent, technological civilizations in the Milky Way galaxy.

Toomanytribbles picked it up and mentioned this was before the many discoveries of extrasolar planets of the last few years.

I'm not sure anyone has had the time to see how what we do know about planets outside the solar system applies to Frank Drake's famous equation. For now I believe most of our extrasolar planetary discoveries have been of planets that orbit their stars quite rapidly and thus "shake" their parent stars so we can see the planets are there.

I'm guessing the major magnitudes of the Drake equation haven't changed that much over the last few decades.

In fact I was just watching the uncut Balance of Terror: Remastered Star Trek episode that Oprah Winfrey and William Shatner gave me last month and there's a scene in that episode where McCoy says to Kirk that there's a "mathematical probability of three million Earth-type planets".

Parallel to Sagan's exuberant, "In the MILLIONS! MILLIONS of technical civilizations ..."

One wonders what they might be up to these days ...