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(建议用时8′)
A new planethunting technique has detected the most earthlike planet yet around a star other than our sun,raising hopes of finding a space rock that might support life,astronomers(天文学家) reported recently.
“This is an important discovery to answer the question ‘Are we alone?’” said Michael Turner of the National Science Foundation.
“The team has discovered the most earthlike planet yet,and more importantly,has proved the power of a new technique that is sensitive(灵敏的) to detecting planets that are fit for people to live on,” Turner said in a statement.
In the last decade,astronomers have detected more than 160 planets moving around stars outside our solar system.Most of these have been gas giant planets like Jupiter,which are unfit for life.
But an international team has detected a cold planet about 5.5 times more massive than the earth—still small enough to be considered earthlike—moving around a star about 20,000 light years away,close to the center of the Milky Way.
To find this new planet,the team used a technique called gravitational microlensing(引力微观透镜法).When a planet is circling the closest star,the planet’s gravity can add its own signature to the light.This kind of light signature was observed on July 11 by a group of telescopes in a project known as OGLE,short for Optical Gravitational Lensing Experiment.
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