2015考研英语阅读另一个地球_大学英语阅读

2015考研英语阅读另一个地球

　　然而，Kepler 22b 是目前发现的最有希望的外行星。不像其他行星不在恒星的适居带，Kepler 22b 在它的适居带舒适地运行。美国国家航空与宇宙航行局的研究人员通过与地球表面温度15C比较，估算出它表面的温度大概是22C。它的母恒星与太阳相似，这又与其他两个候选外行星不同，其他两个候选外行星都环绕较冷的、较昏暗的恒星运行。Gliese 581d的母恒星确实是一个红矮星---最小的星系。那意味着适居带非常接近它以至于行星可能被潮汐力锁住，就像月亮对于地球一样。如果是那样的话，Gliese 581d的一面将会是常年光亮的，而另一面将会是无尽的黑暗。

　　These three potentially habitable exoplanets may soon be joined by many more. In the two and a half years since its launch, Kepler has spotted 2,326 candidate planets. About 650 others have been discovered by other instruments. That plethora allows astronomers to start drawing conclusions about how common various sorts of planets are. Of Kepler s haul, 9% seem to be of a similar size to Earth ; a further 29% are Super Earths-planets substantially larger than Earth that are nevertheless rocky. Forty-eight of Kepler s unconfirmed candidates look as if they orbit within their stars habitable zones; of those, ten seem to be Earth-sized.

　　很快可能有更多的外行星加入这三个可能适合居住的外行星中。 Kepler自发射以来的2年半里已经发现了2,326候选行星。其他仪器大约发现了另外650个行星。大量的行星使天文学家开始得出行星种类繁多的结论。Kepler捕获的行星中9%大小与地球相似 sustain human colonists. If only a few of Kepler s possible Earthlike planets turn out to be real, that third number is likely to be in the millions.