Title: What are the chances of life on another planet?
Headings: What are the chances of life on another planet?
What are the chances of life on another planet?
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Content: The ones most likely to harbor life would be smallish, rocky planets like Earth. Larger planets tend to be composed of hydrogen gas, the most abundant element in the universe, and to not have a solid surface. Good candidates for life would also occupy what scientists call the habitable zone—the zone in which a planet's distance from the parent star makes liquid water possible. The Kepler mission —a space observatory launched by NASA in 1997 to search our galaxy for just these kinds of Earth-like planets—has found one candidate that meets both requirements, Kepler-452b. So the chances of life on another planet are high. However, we have no direct evidence yet of life anywhere other than Earth. The real question is, will we ever find the planet we're looking for, given that we'll have to survey the planetary systems of the universe's estimated 1 billion trillion stars? And if we do find that planet, will we even recognize the life it harbors? There's no real reason why we should expect to discover life as we know it orbiting a star many light years away from our home solar system. There's so much we don't know that we are severely limited in our ability to even think about the question.