研究证实类地球行星的存在
来源：可可英语
发布时间：2012-05-11 15:53:00
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内容提要：VOA慢速:研究证实类地球行星的存在
来源:http://www.kekenet.com/broadcast/201112/165170.shtml
On a clear night, the sky is a wonderful thing. It seems we never grow tired of looking up and thinking. Is there life out there somewhere? Is there another place like Earth where life might exist? If so, where is it? And how far away is it?
Researchers with the American space agency think they know the answers to all those questions except the first. But without the Kepler spacecraft, they would still not know for sure. Last week, scientists announced the latest information from Kepler. The news is exciting!
BARBARA KLEIN: The Kepler spacecraft was named in honor of Johannes Kepler, the seventeenth century German astronomer. It was designed to examine a small part of the Milky Way galaxy and search for places like Earth.
Recently, the spacecraft found "22b", a planet about six hundred light years away. The space agency says it is the first planet in a "habitable zone" outside our Solar System. That means the planet orbits a star like our sun, but it is not too close to it, nor too far away. Because of this position, scientists say, Kepler-22b might have water, one of the main things needed for life.
The newly-discovered planet is about two and a half times larger than the Earth. The planet is closer to its star than we are to the sun. But 22b's sun is smaller than ours, and does not produce as much heat. Scientific instruments have yet to show what the new planet is made of. It could be gas, rocks, or some kind of liquid.
http://www.kekenet.com/broadcast/201112/165170.shtml