評論
打印
If they found even a few martian microbes,
如果他們找到哪怕只是幾種火星微生物
in my opinion,
在我看來
it would be one of the most exciting discoveries ever made.
這將成為有史以來最令人振奮的發現之一
But even if mars is barren,
但是即便火星沒有生命
there are other places to look for liquid water.
仍可以在其它星球尋找液態水
One of them lies a mere 30 million miles from Mars.
其中一處距離火星僅有3萬千英里遠
On a small, mysterious moon that orbits the giant planet Jupiter.
就在大行星木星的一個小而神秘的衛星上
This is Europa.
這就是木衛二
Europa is tiny -- just under 2,000 miles in diameter
木衛二非常小，直徑不到2千英里
and it's very cold -- minus 260 degrees.
而且非常冷，僅有零下260度
The entire moon is covered in a layer of ice perhaps 15 miles thick.
整個衛星被大約15英里厚的冰層覆蓋著
But Europa may have a hidden heat source beneath the surface.
但是木衛二地表以下可能隱藏著一個熱源
Europa orbits Jupiter once every 3.6 days,
木衛二每3.6天就圍繞木星轉一圈
in an egg-shaped path.
其軌道呈雞蛋形狀
The gravitational pull from Jupiter changes constantly,
木星對其的引力不斷變化
stretching, then compressing europa.
不斷拉伸然后擠壓木衛二
This process is like kneading a piece of clay
這過程就像揉捏一塊粘土
to make it warm and soft,
使其變得又熱又暖
and the heat produced may be enough to melt the underside of the ice sheet.
所產生的熱量也許足夠融化冰層的底層
creating a hidden ocean of liquid water protected
從而產生一個隱蔽的液態水的海洋
from the vacuum of space by the solid ice above.
由上面覆蓋著厚厚的冰層保護著與真空隔絕
If so, there could be aliens living here --
若真如此，那里可能有生命存在
creatures that have evolved to exploit this dark and ancient water world.
進化得足以適應這種黑暗和古老的水世界
I think it's even reasonable to guess at some of their physical features.
我認為甚至可能想象得出它們的體征
Aliens here would probably swim in a similar way to our own ocean life,
那里的生命可能和我們的海洋生物一樣游泳
since liquid water is the same stuff everywhere.
因為液態水在哪里都是一樣的
