for National Geographic News
In an atmosphere of looming federal funding cuts, the search for intelligent life on other planets is still capturing the imaginationsand research interestsof astronomers.
Scientists already know that only a tiny fraction of the 200 to 400 billion stars in our galaxy seem to have what it takes to support life on orbiting planets.
Now researchers think they know where such potential habitable starsor "habstars"hang in the sky.
Margaret Turnbull, of the Carnegie Institution in Washington, D.C., recently released her list of top five potential habstars in our galaxy, three of which can be seen from Earth with the naked eye.
Locating these sunlike stars, she says, is a step toward the eventual search for life on other planetsintelligent or otherwise.
"What we are thinking about now is to detect the stars, then the planets, and then life,'' Turnbull said.
The astronomer announced this list last week during the annual meeting of the American Association for the Advancement of Science in St. Louis, Missouri.
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Scientists have spent years identifying and studying the basic characteristics of stars in our galaxy, the Milky Way.
They have found that stars vary in their characteristics, and that some probably harbor "habitable zones.''
Astronomers use this catch-all phrase to describe both the region around a star that may support life on planets and areas on planets that are friendly to life.
Turnbull pored over vast amounts of information about stars to come up with an initial catalog of 17,129 potential habstar systems, which she released in 2003.
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