Hot Planet

StarDate: April 17, 2009

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Venus is slowly climbing away from the Sun this month. The brilliant "morning star" is quite low in the east at first light, but will climb higher as we roll through spring.

Venus is the hottest planet in the solar system. Its thick atmosphere holds in heat from the Sun, warming the planet to almost 900 degrees Fahrenheit.

But Venus is positively chilly compared to a planet that was recently discovered in another star system. Temperatures there could soar to 2,000 degrees or hotter.

A European spacecraft named Corot discovered the planet orbiting a star that's about 450 light-years away. As the craft watched, the star got a little fainter as the planet passed directly in front of it, blocking a little of its light.

From the timing of the event and the star's size and distance, scientists calculated that the planet is less than twice the diameter of Earth. That makes it one of the smallest planets yet discovered. And like Earth, it's probably a solid ball of rock and metal.

The planet orbits the star in less than a day, which means that they're only about a million and a half miles apart. At that distance, the planet is seared like a rack of ribs on a barbecue grill. Its surface may be covered with molten rock. And it's possible that the planet has a thick, dense atmosphere, like Venus's. If so, it could be filled with water vapor -- turning the surface of this hot little planet into a giant steam bath.

Script by Damond Benningfield, Copyright 2009

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