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NOVA scienceNOW: Hunt for Alien Earths
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Program Overview
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For years, astronomers have tried to determine whether humans are
alone in the universe. While their quest for evidence of other
Earth-like planets has so far been fruitless, promising new search
techniques could soon reveal the answer. The discovery of planets
around other stars—especially Earth-like ones—will help
us better understand the likelihood of life elsewhere in the
Universe.
This NOVA scienceNOW segment:
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explains how, when trying to locate extrasolar planets,
scientists have had success using the "wobble method"—a
technique that infers a planet's existence based on its
gravitational pull on its parent star.
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notes that finding Earth-like planets with the wobble method is
difficult because the mass of an Earth-like planet does not
exert as much of a pull on its nearby star as a larger planet,
such as Jupiter.
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reports on the "transit method," a way to find planets by
detecting a slight dimming of the star's brightness as the
planet passes in front of its star, as seen from Earth.
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points out that while the transit method has detected several
new planets, so far they have all been Jupiter-sized and are
uninhabitable.
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reports that the just-launched Kepler space telescope will spend
the next three to four years looking for planetary transits
across more than 100,000 stars in the constellation Cygnus that
are similar in mass to the sun.
Taping Rights: Can be used up to one year after the program
is taped off the air.
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