太陽系外現宜居星球 人類"移民"有望
今日，天文科學家正式對外宣佈，在太陽系之外發現了一顆距離在20光年左右的適合生命體生存的星球。
The 'exoplanet' Gliese 581d has conditions that could support Earth-like life, including possible watery oceans and rainfall.
這顆名爲格利澤 581d的外部星提供了可供生命存在所需的條件，在格利澤上可能存在有類似於誰的海洋和降雨。
Yet any future space voyagers landing there would find themselves in truly alien surroundings. The sky is likely to be murky red, not blue, and gravity is twice what is on Earth, doubling the weight of anyone standing on the surface.
不過當未來的太空旅行者在那可星球上着落時，可能會發現自己正處於名副其實外形環境，哪兒的天空不是藍色，而是紅色的，引力也可能是地球的兩部，任何人站在星球表面，體重都將是地球上的兩倍。
In addition, the planet's carbon dioxide-rich atmosphere would almost certainly not be breathable by humans.
此外，這個星球的大氣中充滿了二氧化碳，人類幾乎是無法呼吸的。
Scientists were surprised by the discovery because Gliese 581d was previously ruled out as a habitable planet candidate.
科學家們對於這項發現感到非常意外，因爲在此前格利澤 581d一直被排除在適宜居住的星球之外。
But a new computer model capable of simulating extraterrestrial climates has shown the previous assumption to be wrong, and confirmed that Gliese 581d really could harbour life.
一項新的電腦建模模擬了外星其後，這推翻了之前錯誤的假設，並證實格利澤 581d其實是適合生命存在的。
Scientists believe the findings could pave the way to more discoveries of potential havens for life among the stars, including some that are strange and unexpected.
科學家們相信，這項發現可以爲今後發現更多的適宜生命生存的行星拓寬道路，其中可能包括怪異和意想不到的星球。
Dr Robin Wordsworth, a member of the French team from the Institut Pierre Simon Laplace in Paris, said: 'This discovery is important because it's the first time climate modellers have proved that the planet is potentially habitable, and all observers agree that the exoplanet exists.
法國的羅賓·華茲華斯教授是巴黎皮埃爾西蒙拉普拉斯研究所的成員之一，他說：“這項發現非常重要，是首次通過模擬行星的其後來判斷其是否適宜生存，所有的觀察員他在這顆外部行星存在的問題上達成了統一的認定。”
'If you look at the history of the search for habitable planets, there's been at least two instances so far when scientists have announced that a habitable world has been discovered, only to have the claim contradicted later, either by climate experts or by other observers.
“在研究尋找適宜居住行星的歷史之後，你會發現目前至少有兩個例子，在天文學家宣稱找到了適合的目標之後，氣象專家或者其他觀察員總會將之否定。”
'The Gliese system is particularly exciting to us as it's very close to Earth, relatively speaking. So with future generations of telescopes, we'll be able to search for life on Gliese 581d directly.
“格利澤的系統尤爲使我們感到興奮，因爲它距離地球很近，在將來利用天文望遠鏡，我們或許就能直接關發到這個星球上是否有生命的存在。”
'This said, the fact that a planet so unlike the Earth could be habitable bodes pretty well for the search for life in general.
“也就是說，這樣一個與地球非常類似的星球居然適合居住，這也預示着尋找生命存在的大好前景。”
'I think it's becoming clearer with every discovery we make in exoplanet science that the variety of worlds out there in the universe is going to be far greater than the few examples we are used to from our Solar System.'
“我認爲隨着對太陽系以外行星的進一步瞭解，情況越來越明朗，我們不應該將目光僅限於太陽系內的爲數不多的星球，宇宙中還有大量的帶我們探索的世界。”
