8.30諸多巧合使地球成為宜居星球

1、what makes earth special compared to other planetsby clara moskowitz, staff writer諸多巧合使地球成為宜居星球什么造就了地球較之于其他行星的獨(dú)特之處？1earth is one special planet.1地球是一顆獨(dú)特的行星。2it has liquid water, plate tectonics, and an atmosphere that shelters it from the worst of the suns rays. but many scientists agree our planets

2、 most special feature might just be us.2地球上有流動(dòng)的水、板塊構(gòu)造以及使之免受太陽直射的大氣層。但很多科學(xué)家認(rèn)為，地球的最獨(dú)特之處可能恰恰是地球上的生命。3to enable life, planet earth has a number of ideal features. it is unique among planets in our solar system for having water in its liquid form at the surface, in an amount conducive to life evolving.3地

3、球?yàn)樯拇嬖谔峁┝撕芏嗬硐霔l件。它是太陽系中一顆獨(dú)特的行星，表面有大面積流動(dòng)的水，有利于生物進(jìn)化。4the most impressive attribute of the earth is the existence and amount of liquid water on its surface, said geoffrey marcy, an astronomer at the university of california, berkeley who has helped discover dozens of extrasolar planets. no one knows wh

4、y earth has the exact amount of water it does, which is relatively small considering that water molecules outnumber silicate molecules in the galaxy, he said.4伯克利加州大學(xué)的天文學(xué)家杰弗里.馬西說，沒有人能確切地知道，地球上到底有多少水，粗略估計(jì)，銀河系中水分子數(shù)要多于硅化物分子數(shù)。5the earth is remarkable for its precisely-tuned amount of water, not too much

5、 to cover the mountains, and not so little that its a dry desert, as are mars he said.5他說：“值得一提的是，地球上量恰到好處，水太多則會(huì)淹沒山脈，像火山一樣水太少則會(huì)成為干涸的沙漠?！?earths water is also special in that it has remained liquid for so long. how has earth been able to hold on to its oceans while those on other planets freeze or fr

6、y?6同時(shí)，地球上的水獨(dú)特之處還在于它能一直流動(dòng)。為什么地球能夠讓海洋水保持流動(dòng)，而其他行星上的水要么冰冷要么沸騰呢？7many details as to why earth is the only planet with liquid water in our solar system need to be worked out, said diana valencia, a graduate student in earth and planetary sciences at harvard university. certainly the distance to the sun ha

7、s made it possible. a planet much farther in would receive too much energy from the sun, and a planet too far out would quickly freeze.7哈佛大學(xué)地球行星學(xué)研究生黛安娜.巴倫西亞說：“對(duì)于為什么地球是太陽系中唯一擁有流動(dòng)水的行星，還有很多具體問題有待解決。地球與太陽的距離當(dāng)然是一個(gè)原因。距離太近的行星會(huì)吸收過多的太陽能，太遠(yuǎn)則很快會(huì)被冰凍?！?our planets just right location in the solar system has help

8、ed, as has its system of plate tectonics the slip-sliding movements of earths crust that are thought to have created the planets towering mountain ranges and plummeting ocean depths.8地球在太陽系中“恰到好處”的位置使它受益，而板塊構(gòu)造體系-地球外殼的滑移運(yùn)動(dòng)也是如此。具信，正是地殼運(yùn)動(dòng)形成了地球表面高聳的山峰和深邃的海洋。9the fact that earth has plate tectonics allow

9、s for the carbon-silicate cycle to operate over geological timescales, valencia said. with the carbon-silicate cycle, the levels of carbon in the atmosphere get regulated to keep the surface temperature around that of liquid water.9巴倫西亞說：“地球的板塊構(gòu)造使碳硅化合物在地質(zhì)年代中不斷循環(huán)。由于這一循環(huán)，大氣中碳的含量得到調(diào)節(jié)，從而保持了流動(dòng)水域范圍的表面溫度?！?/p>

10、10plate tectonics and water are inextricably linked. not only does plate tectonics enable liquid water to exist by way of regulating the temperature, but many scientists have argued water enables plate tectonics to happen.10板塊構(gòu)造和水密切相關(guān)。板塊構(gòu)造不僅能通過調(diào)節(jié)溫度使水流動(dòng)，同時(shí)，很多科學(xué)家都認(rèn)為水促成了板塊構(gòu)造。11without water the planet

11、would be geologically dead, said caltechs mike brown, water is what lubricates plate tectonics, which is what leads to the extreme difference between continents and seafloors, the large amount of earthquakes and volcanoes, fresh mountain-building. venus has no water, no plate tectonics, no deep sea

12、floor, no steep mountains, no continents, probably few earthquakes or volcanoes. a much less geologically interesting place!11加州理工大學(xué)的邁克.布朗說：“如果沒有水，在地質(zhì)學(xué)上這個(gè)行星就是死的。水潤滑了板塊構(gòu)造，而板塊構(gòu)造導(dǎo)致了大陸和海底之間的顯著區(qū)別，引發(fā)了地震和火山，改變了山脈的面貌。金星上沒有水，沒有板塊構(gòu)造，沒有深邃的海底，沒有屹立的山峰，沒有大陸，可能也極少有地震或火山。一個(gè)幾乎毫無生氣的地方！”12another just-right aspect of

13、earth is its size: if it was much smaller, it wouldnt be able to hold on to our precious atmosphere, but much larger and it might be a gas giant too hot for life.12地球的大小也“恰到好處”：太小就無法吸附寶貴的大氣層，太大則不可能太熱使生命生存。13the presence of jupiter, blocking earth from much of the incoming debris, has also helped ear

14、th become a safe haven for life. jupiter acts like a giant broom, sweeping the solar system of debris that could snuff out life in one fatal blow. this protective effect was particularly helpful in the solar systems early years, when earth still got pummeled but, scientists say, not nearly as bad as

15、 would have been the case without jupiter.13木星的存在為地球當(dāng)住了大部分天體碎片，也有助于地球成為生命的“安全港”。木星就象一把巨大的掃帚，清掃太陽系中的碎片-一旦被這些大大小小的巖石擊中，生命就會(huì)戛然而止。在太陽系早期，這一保護(hù)作用非常有用，盡管當(dāng)時(shí)地球仍然受到撞擊，但科學(xué)家說，如果沒有木星，情況會(huì)糟糕得多。14life on earth may also owe a debt to our nearest celestial neighbor, the moon.14地球上的生命還應(yīng)感謝距離我們最近的天體月球15earths moon stabi

16、lizes our planets rotation, preventing drastic movements of the poles that could cause massive changes in climate that some scientists think could have doomed any chance for budding life to form or evolve.the moon also helpfully pulls the oceans tides, which scientists suggest might have been the perfect place for early life to begin evolving to survive on land. 15月球使地球穩(wěn)定穩(wěn)定旋轉(zhuǎn)，防止地球兩極劇烈運(yùn)動(dòng)而導(dǎo)致氣候劇烈變化。一些科學(xué)家認(rèn)為，要是發(fā)生這樣的變化，孕育著的生命就不可能形成或進(jìn)化。一些科學(xué)家認(rèn)為，要是發(fā)生這樣的變化，孕育著的生命就不可能形成或進(jìn)化，孕育著的生命就不可能形成或進(jìn)化。同時(shí)，月球也有效地引發(fā)潮汐，科學(xué)家認(rèn)為，海洋可能是早期生命開始進(jìn)化得以在陸地生存的最佳環(huán)境。16though e