The Drake Equation uses mathematics to estimate the scope of the SETI project. But what is the Drake Equation? What is SETI? Could other equations prepare for similar projects seeking signs of alien life on exoplanets?

## Mathematics vs. Starry Eyes and Fuzzy Thinking

A traditional challenge to a know-it-all is to “*count the stars*.” Even from a light-polluted city, the number of stars in the night sky quickly overwhelms the casual stargazer.

Modern astronomy estimates there are about 200 billion stars in our own Milky Way galaxy.

What are the chances of alien life on other planets orbiting some of those stars in our galaxy?

The temptation of fuzzy thinking would lead to the reply, “*There are so many stars. Surely some planets must be inhabited, since physics and chemistry would work in the same way everywhere in the universe*.” Enter the Drake Equation.

## What is the Drake Equation?

Dr. Frank Drake proposed the Drake Equation to reduce that fuzzy thinking.

First, he sharpened the question from “*inhabited planets*” to *“planets with civilizations that could exchange radio messages with Earth*.”

He then proposed that a simple equation with seven parameters could calculate the number of worlds from which we might expect to receive signals.

So ‘N’ is simply the result of multiplying the seven factors in the infographic above.

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