发现:适宜生命存活的一类地行星

    An Earth-size planet has been spotted¹ orbiting a nearby star at a distance that would makes it not too hot and not too cold - comfortable enough for life to exist, researchers announced September 29.
    If confirmed, the exoplanet, named Gliese 581g, would be the first Earth-like world found residing in a star's habitable zone - a region where a planet's temperature could sustain liquid water on its surface. And the planet's discoverers are optimistic about the prospects² for finding life there。
    "Personally, I would say, my own personal feeling is that the chances of life on this planet are 100 percent," said Steven Vogt, a professor of astronomy and astrophysics at the University of California. "I have almost no doubt about it."Gliese 581g is one of two new worlds the team discovered orbiting the red dwarf³ star Gliese 581, bumping that nearby star's family of planets to six. The other newfound planet, Gliese 581f, is outside the habitable zone, researchers said。
    The star is located 20 light-years from Earth in the constellation⁴ Libra. Red dwarf stars are about 50 times dimmer than our sun. Since these stars are so much cooler, their planets can orbit much closer to them and still remain in the habitable zone. Estimates suggest Gliese 581g is 0.15 astronomical⁵ units (One astronomical unit is the average distance between the Earth and sun) from its star, close enough to its star to be able to complete an orbit in just less than 37 days。
    Gliese 581g has a mass three to four times Earth's, the researchers estimated. From the mass and estimated size, they said the world is probably a rocky planet with enough gravity to hold onto an atmosphere. Just as Mercury is locked facing the sun, the planet is tidally locked to its star, so that one side basks⁶ in perpetual daylight, while the other side remains⁷ in darkness. This locked configuration⁸ helps to stabilize⁹ the planet's surface climate, Vogt said. Between blazing heat on the star-facing side and freezing cold on the dark side, the average surface temperature may range from minus 31 to minus 12 degrees Celsius¹⁰, the researchers said。
    据美国太空网9月29日报道，研究人员最新宣称探测到一颗类似地球的行星，其环绕邻近恒星距离适中，得以保持适宜的气候和温度——舒适程度足以让生命存活下来。
    如果得以证实，这颗被命名为“Gliese 581g”的系外行星将成为第一颗类似地球的世界——该行星的温度可维持表面存在液态水。而探测者们则因此对找到外星生命充满希望。
    “就个人角度而言，我认为这颗行星上存在生命的概率为100%，”美国加州大学圣塔克鲁兹分校天体物理学家史蒂文-沃格特说。“对此我几乎毫不置疑。”
    Gliese 581g是环绕红矮星Gliese 581两颗行星中的其中一颗，它的发现使该行星系内行星数量增加至6颗。研究人员称，另一颗新发现的行星是Gliese 581f，位于适宜居住区域之外。
    而红矮星Gliese 581位于天秤星座，距离地球20光年，大约比太阳昏暗50倍。由于这样的恒星温度相对较低，它的行星在近距离环绕其运行的同时还能保持着适宜的气候和温度。初步分析认为Gliese 581g与恒星的距离为0.15个天文单位(一个天文单位约等于地球至太阳的平均距离)，较近的轨道距离使得该行星公转一周只需37天。
    研究人员估测Gliese 581g行星的质量大约是地球的3到4倍。基于该行星的质量和预测体积，研究人员称该行星很可能是一颗岩石行星，具有足够的引力维持大气层。与水星总有一半固定地面对太阳相似，该行星总是始终保持一面朝向恒星，使得星球的一半永久处于阳光之中，而另一半则永久位于黑暗。沃格特称，这种特征有助于稳定行星的表面气候。研究人员还称，在炽热和寒冷的两个半球之间，该星球平均表面温度为零下31摄氏度至零下12摄氏度。

1 spotted   

adj.有斑点的，斑纹的，弄污了的

参考例句：

• The milkman selected the spotted cows,from among a herd of two hundred.牛奶商从一群200头牛中选出有斑点的牛。
• Sam's shop stocks short spotted socks.山姆的商店屯积了有斑点的短袜。

2 prospects   

n.希望，前途(恒为复数)

参考例句：

• There is a mood of pessimism in the company about future job prospects. 公司中有一种对工作前景悲观的情绪。
• They are less sanguine about the company's long-term prospects. 他们对公司的远景不那么乐观。

3 dwarf   

n.矮子，侏儒，矮小的动植物；vt.使…矮小

参考例句：

• The dwarf's long arms were not proportional to his height.那侏儒的长臂与他的身高不成比例。
• The dwarf shrugged his shoulders and shook his head. 矮子耸耸肩膀，摇摇头。

4 constellation   

n.星座n.灿烂的一群

参考例句：

• A constellation is a pattern of stars as seen from the earth. 一个星座只是从地球上看到的某些恒星的一种样子。
• The Big Dipper is not by itself a constellation. 北斗七星本身不是一个星座。

5 astronomical   

adj.天文学的，（数字）极大的

参考例句：

• He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
• Houses in the village are selling for astronomical prices.乡村的房价正在飙升。

6 basks   

v.晒太阳，取暖( bask的第三人称单数 )；对…感到乐趣；因他人的功绩而出名；仰仗…的余泽

参考例句：

• The cat basks before the fire. 猫常在火炉前取暖。 来自辞典例句
• The serpent coils in the grass of the streets, the lizard basks in the solitary halls. 毒蛇盘绕在街头的草丛中，蜥蜴在残败的大厅中自由爬行。 来自辞典例句

7 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

8 configuration   

n.结构，布局，形态，(计算机)配置

参考例句：

• Geographers study the configuration of the mountains.地理学家研究山脉的地形轮廓。
• Prices range from $119 to $199,depending on the particular configuration.价格因具体配置而异，从119美元至199美元不等。

9 stabilize   

vt.（使）稳定，使稳固，使稳定平衡；vi.稳定

参考例句：

• They are eager to stabilize currencies.他们急于稳定货币。
• His blood pressure tended to stabilize.他的血压趋向稳定。

10 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。