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　　Ever look at the sky and wonder“Are we alone in the universe?”Many people have dreamed about intelligent aliens and humans making contact. But others have done more than dream: Since 1984, scientists at the SETI Institute in California have been searching the skies for signals from other worlds. They believe that we are not alone.

　　SETI stands for“Search for Extra-Terrestrial Intelligence.”SETI scientists are not just searching for signs of life from other planets, but evidence of intelligent life: life capable of developing language, civilization, culture, and technology. The scientists are sure these aliens are out there. Somewhere.

　　What makes scientists at SETI certain they are not wasting their time? The Drake Equation, written in 1961, assures them that aliens do exist. Combining factors such as the number of planets in the universe, and the likelihood that water exists on some of them, the Drake Equation states that there are millions of civilizations in the universe.