Researchers find "lonely planets"

     BEIJING, May 20 (Xinhuanet) -- Scientists have discovered a Jupiter-sized exoplanet that is completely unbound from a host star, according the scientific journal "Nature" published Thursday.

    The research was conducted by astrophysicists from Osaka University in Japan.

    Using the technique called "gravitational(重力的) microlensing", scientists turned their telescopes towards the centre of the Milky¹ Way and detected this "lonely planet" moving in a extremely large orbit, which suggested it does not connect to any solar system.

    Then they estimated the total number of such wondering planets could be as many as 400 billion, based on the detection efficiency. This number far outnumbers the main-sequence stars such as our Sun.

    "This is an amazing result, and if it is right, the implications for planet formation are profound," says astronomer² Debra Fischer at Yale University in New Haven³, Connecticut.

    And scientist began to consider the possibility that liquid water could exist on this kind of unbound planets. "That might be an attractive possibility for life," said David Stevenson, a planetary scientist at the California Institute of Technology.(本文由在线英语听力室整理编辑)

1 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

2 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

3 haven   

n.安全的地方，避难所，庇护所

参考例句：

• It's a real haven at the end of a busy working day.忙碌了一整天后，这真是一个安乐窝。
• The school library is a little haven of peace and quiet.学校的图书馆是一个和平且安静的小避风港。