Frank Drake in 1961 tackled a most puzzling question:

*Does there exists any intelligent extra-terrestrial life in our Milky Way galaxy? *

Drake came up with a method to estimate how many alien civilizations can actually communicate with us. It is known as the **Drake Equation** and it multiplies together 7 numbers. Each number is denoted by a symbol.

Multiply all these numbers together, you will have a prediction of the number of alien civilization in our galaxy that can communicate with us.

Try putting in some numbers in the Drake Equation Calculator and see what you predict for the number of alien civilizations.