WPL 文集 搜寻第二个地球 Search for the 2nd Earth 侯永正 随着中国神州5号宇宙飞行的成功，随着“火星快车”“机遇”号“勇气”号相继登陆火星，近年来，人类在探索太空方面，不断取得新的进展，令人兴奋的消息不断出现于报断：欧洲“火星快车”最新发现：火星南极 有冰冻水 专家称火星上存在大量水不容置疑 …… “勇气”拍到火星表面岩石……” 机遇”号发回彩色火星照片……利用”哈勃”太空望远镜首次在太阳系外行星的大气层中发现氧元素和碳元素,而氧是寻找地球外生命的重要参考指标之一……在火星上，“勇气”号与“火星快车”取得联系…… “航天热”在世界各地升温,尤其在美国。美国总统Bush宣布了美国政府制定的雄心勃勃的太空新计划：在2015年后，在月球建立永久基地；2030年后，美国宇航员将前往火星探险….. 俄罗斯也在进行着同样的送宇航员去火星探险的种种准备….. 这使笔者想起前不久读到的”搜寻第二个地球”的文章,是啊,随着”航天热”的升温,随着人类在开发外太空方面的进展,人类在宇宙找到第二个地球,在其他星球上找到新人类的梦想也许将变成现实。 下面摘抄一下“Search for 2nd Earth”那篇文章： WASHINGTON：After 15 years of searching ，astronomers said last week they had found an alien planetary system that reminded them a lot of home. This was the first time for planet-hunters to detect what they believe is a Jupiter-like gas ball orbiting a star much like our Sun. It is located at a distance that allows for the possibility of an unseen Earth-type rocky planet orbiting in between. In the last decade and a half ,scientists have found more than 90 so-called extrasolar planets around stars outside our solar system . But none of these earlier discoveries has held the same potential to answer an essential question: Might there be other planets like Earth in the universe ? “We have a (planetary) system that is maybe not a brother or sister of our solar system …it might be more accurately classified as a distant relative, ”Paul Butler of the Carnegie Institution of Washington told reporters at the US’s National Aeronautics and Space Administration (NASA)headquarters. Butler and fellow planet-hunter Geoffrey Marcy of the University of California-Berkeley noted that the newly discovered Jupiter-type planet is the third thought to orbit 55 Cancri , in the system of stars known as Cancer that can be seen from Earth without telescopes . It is about as old ——5 billion years or so ——and about the same size as our Sun. The newly discovered planet moves in an orbit similar to Jupiter’s . Aside from its known planets, the new system has a tantalizing gap between the new Jovian discovery and two other big gas planets orbiting very close to the star , Marcy said . “There’s a huge region centered at about Earth-Sun distance , and in that gap…an Earth-mass planet could exist …and such a planet would be stable , “ he said . …… | 
