On a clear night, the sky is a wond

On a clear night, the sky is a wonderful thing. 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?
Recently, the Kepler spacecraft found “22b”, a planet about six hundred light years away. It is the first planet in a “habitable zone” outside the solar system. That means the planet orbits(环绕) a star like our sun, but it is not too close to it, nor too far away. Because of this position, 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. It is closer to its star than we are to the Sun, but 22b’s sun is smaller than ours, and doesn’t produce as much heat. Scientific instruments show the new planet could be made of gases, rocks or some kinds of liquids.
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(星系)and search for places like the Earth. It was made to inspect over 150,000 stars and measure how bright they are. It looks to see if a star’s brightness gets less over a short time.
If a planet passes between Kepler and the star, it blocks out part of the light. That is what suggested to scientists that there is at least one planet orbiting the star. The instruments on Kepler show the new planet as a small, black dot moving across its sun. An important part of the Kepler experiment is on the Earth. After the spacecraft gathers information, scientists use the telescopes on the ground.
Scientists have found over 2,300 new planets since Kepler was launched. Most are much larger, but it is the new planet’s distance from its star that is important. For life to possibly exist there, the planet’s temperature must not be too hot or too cold.