Hot Planet

StarDate: December 24, 2009

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The dayside is hotter than a stovetop. The sun never rises over the nightside. And the boundary between them is probably a zone of powerful, never-ending storms.

Welcome to a planet known as HAT-P-7b. It was discovered just last year. And a spacecraft recently found that it has an atmosphere -- at least for now.

The Kepler mission is designed to hunt for "Goldilocks" planets -- worlds like Earth, where the temperature is just right for liquid water -- a key ingredient for life. It'll find them by watching as the planets cross in front of their parent stars, causing their light to dim by a tiny bit.

It'll take several years to find and confirm these Earth-like worlds. But in the meantime, Kepler is making other discoveries. An example is the atmosphere around HAT-P-7b. The planet orbits a star that's roughly between Vega and Deneb, two bright stars that are well up in the west at nightfall.

The planet is a giant, like Jupiter, the largest planet in our own solar system. It's only three and a half million miles from its parent star, so it orbits the star every couple of days.

HAT-P-7b is "locked" so that the same side always faces the star, just as the same side of the Moon always faces Earth. So the star shines on the dayside like a blast furnace, heating the atmosphere to almost 5,000 degrees Fahrenheit. The heat may boil the atmosphere off into space -- creating a world that Goldilocks would not find just right.

Script by Damond Benningfield, Copyright 2009

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