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The figures have since been refined and made a little more generous,
自那以后，這兩個數字被更精確地測算了一遍，放寬了一點，
5 percent nearer and 15 percent farther are thought to be more accurate assessments for our zone of habitability—but that is still a narrow belt.
再近5%，再遠15%，但仍是個窄帶。
The discovery of extremophiles in the boiling mudpots of Yellowstone and similar organisms found elsewhere
（由于在黃石公園沸騰的泥潭里發現了極端微生物和在別處發現了類似的微生物，
made scientists realize that actually life of a type could range much farther than that-even, perhaps, beneath the icy skin of Pluto.
科學家們認識到，某種真正的生命的分布范圍要比這廣得多——甚至可能出現在冥王星的冰面底下。
What we are talking about here are the conditions that would produce reasonably complex surface creatures.)
我們在這里討論的只是能產生比較復雜的地表生物的條件。）
To appreciate just how narrow, you have only to look at Venus.
若要了解幅度為何很小，你只要望一眼金星。
Venus is only twenty-five million miles closer to the Sun than we are.
金星離太陽只比我們近2 500萬公里。
The Sun's warmth reaches it just two minutes before it touches us.
太陽的熱量射到那里只比我們早兩分鐘。
In size and composition, Venus is very like Earth, but the small difference in orbital distance made all the difference to how it turned out.
金星的大小和結構很像地球，但是，軌道距離上的小小差別，產生了全然不同的結果。
It appears that during the early years of the solar system Venus was only slightly warmer than Earth and probably had oceans.
看來，只是在太陽系形成之初，金星才比地球稍稍暖和一點，而且很可能有海洋。
But those few degrees of extra warmth meant that Venus could not hold on to its surface water, with disastrous consequences for its climate.
但是，熱這么幾攝氏度就意味著金星無法留住表面的水，結果對氣候造成了災難性的后果。
As its water evaporated, the hydrogen atoms escaped into space,
隨著水分的蒸發，氫原子逸入太空，
and the oxygen atoms combined with carbon to form a dense atmosphere of the greenhouse gas CO2.
氧原子與碳在大氣里形成了厚厚的一層溫室氣體一氧化碳。
Venus became stifling.
金星變得令人窒息。
Although people of my age will recall a time when astronomers hoped that Venus might harbor life beneath its padded clouds, possibly even a kind of tropical verdure,
我這樣年齡的人還記得起，天文學家們曾一度希望，在密密的云層下面，甚至可能是在郁郁蔥蔥的熱帶植物下面，
we now know that it is much too fierce an environment for any kind of life that we can reasonably conceive of.
金星上存在著生命，但我們現在知道，那里的環境過于惡劣，不適與我們所能想象的任何生命。
