了解宇宙是如何运行的（2010）

the outermost moons are more ice rich
所以从很多方面看
so, in a lot of ways
这就是个迷你太阳系
a little miniature solar system
木星是宇宙中的操控大♥师♥
jupiter is a cosmic puppet master
它操控着周围的卫星
controlling and manipulating its moons
或许还能让其中一个卫星孕育出生命
and perhaps making one of them home to life
2007年3月1日
march 1st, 2007
新视野号♥探测器是美国国家航♥空♥航♥天♥局
于2006年1月19日在佛罗里达州卡纳维拉尔角
肯尼迪航♥天♥中心发射升空的冥王星探测器
其主要任务是探测冥王星及其最大的卫星卡戎
并附带探测位于柯伊柏带的小行星群
Nasa的新视野号♥探测器
nasa's new horizons probe flies past io
飞过和地球差不多大的木卫一
a moon roughly the same size as our own
木卫一是太阳系最有趣的卫星之一
io is one of the most interesting moons in the solar system
不只是因为它看起来像个披萨
and not just because it looks like a pizza
它的表面密布火山
it's covered with volcanoes
事实上 这些火山还在持续喷发
in fact, these volcanoes, one way or another have been continuously erupting
自从我们使用太空探测器观察木卫一
since we've been observing io with space probes
过去20年来一直看到（火山喷发）
for the past 20 years
这颗小卫星
this small moon
是太阳系火山活动最频繁的天体
is the solar system's most volcanic body
它至少有400座活火山
with at least 400 active volcanoes
这些火山喷发出的热量是地球的100倍
together, they pump out 100 times more heat than volcanoes on earth
木卫一绕木星运行的轨道是个偏心圆
io's orbit is actually slightly eccentric around jupiter
它跟木星之间的距离时近时远
sometimes, it's a little closer to jupiter sometimes, a little farther away
因为引力场的改变
as the gravitational field changes
木卫一的本体结构
io's body, the structure of the moon itself
会受到扭曲和来回拉扯
is twisted and pulled back and forth
进而产生摩擦 让木卫一的内部变热
and that heat through friction the interior of the moon
热量融化木卫一的内部
that heat basically melts it
融化物质便从火山喷发出地表
and that erupts through the surface as volcanoes
木卫一的火山很有意思
the volcanoes on io are really fascinating
它们会将大量的二氧化硫
they're ejecting vast quantities
喷到木卫一的地表上方
of sulfur dioxide above the surface of io
太阳的紫外线会将二氧化硫
it's split apart by the ultraviolet light
分解成硫离子和氧离子
from the sun into sulfur ions, oxygen ions
而这些离子
and those ions interact
会和木星的磁场产生交互作用
with the magnetic field of the planet jupiter
木星磁场会带走木卫一的化学物质
jupiter's magnetic field carries chemicals
和带电的离子
and charged particles away from io
并带到附近的卫星木卫二
and onto its neighboring moon, europa
由此这个遥远的冰冻世界
making this distant, frozen world
使我们最有可能发现外星生命的地方
one of our best hopes of finding alien life
我们使用探测器接近木卫二时
when we got up close to europa with spacecraft
看到它的表面密布着裂痕和山脊
we saw it was covered in cracks and ridges
这种现象很像是
which looked very much
地球冰河时期冰河蚀刻的痕迹
like the way ice floes look here on earth
结果事实果真如此
and it turns out that's exactly what's going on
我们发现木卫一的地表示存在
we know, because of seeing the flexure of the ice
带有断口跟裂痕的冰隙
and the cracks in the ice on the surface of europa
由此我们推断那个冰质卫星
that there's probably a sub-surface ocean
或许有比地球最深的海还要深的地下海
deeper than the deepest of earth's oceans there on that little icy moon
木星的引力来回拉扯木卫二
jupiter's gravity pushes and pulls europa
产生摩擦
creating friction
摩擦生热 进而融化木卫二的内部
generating heat and melting europa from within
木星离太阳如此远
jupiter is so far away from the sun that it's natural
我们当然会认为它周围的一切都是冰冻的
to assume that anything around it is frozen
事实上 引力足以产生热量
the fact that gravity can heat something up enough
来制♥造♥出液态水 这是非常重要的
to produce liquid water is profoundly important
之前我们全是靠间接证据推断
all of the indications of liquid water under the surface
木卫二地下有水
have been indirect
像是地表似乎有经过更新期
the way the surface looks, the resurfacing of it
但是最近我们发现了木卫二有地下水的直接证据
but very recently, we got direct evidence of water
就是从木卫二南极喷出的
under the surface of europa in the form of a geyser
间歇性水柱
a plume of water being ejected from the south pole of the moon
2013年11月
november 2013
哈勃空间望远镜以天文学家爱德温·哈勃为名
哈勃望远镜接收地面控制中心的指令
并将各种观测数据通过无线电传输回地球
由于哈勃空间望远镜位于地球大气层之上
因此影像不受大气湍流的扰动 相度绝佳
无大气散射造成的背景 还能观测紫外线
科学家从哈勃太空望远镜拍到的照片中
analyzing photographs from the hubble space telescope
发现2座喷出124英里（约200公里）高的间歇泉
scientists spot two giant geysers spewing water 124 miles
直接喷入木卫二的大气层
into the atmosphere above europa's south pole
这是目前最棒的
it's the best evidence yet
证明木卫二的冰冻地表下面有液态水的直接证据
of liquid water beneath europa's frozen crust
看到木卫二有液态水的直接证据
seeing direct evidence of liquid water on europa
真是令人兴奋
is terribly exciting
找到了液态水 就有希望找到生命
finding liquid water is very important for finding biology
我们不敢说有水就一定有生命
we don't know that wherever there's water, there's biology
但是我们肯定要是没有水
but we're pretty sure that without it
生命更难出现
it would be a lot tougher
生命要演化
for life to evolve
就需要水和其他化学物质
it needs water and other chemicals
这时木星磁场就派上了用场
and that's where jupiter's magnetosphere comes in
磁场可以把火山卫星木卫一
the network that transports chemicals
喷发出的化学物质带到木卫二
from volcanic moon io to europa
科学家认为这个磁场可以携带硫 碳和其他矿物质
scientists think the magnetosphere delivers sulfur carbon and other minerals
而它的辐射
and that its radiation
可以将木卫二表面的冰冻水分子分解为氢和氧
splits apart frozen water molecules on europa's surface into hydrogen and oxygen
从生物学的角度来看 重点是
from a biology point of view, what's important is
这些有趣的物质在木卫二的地表生成
that there's interesting stuff being made on the surface
如果这些物质能够进入海洋
and if that stuff could get carried into the ocean
就能有利于生物发展
organisms might appreciate
木卫二的间歇泉是一个重大发现
so, europa's geysers are a major discovery
看到木卫二的间歇泉 真叫人兴奋
one of the more exciting aspects of seeing this geyser on europa
这就表示
is it means that the liquid ocean
地表下的液态海洋有办法涌出地面
underneath the surface has a way of getting out
也就是说 地表示的物质
which means maybe there's a way of stuff
或许有办法进入地下海
from the surface getting into the ocean itself
也许在这个海洋里
it could be that in this ocean
有营养丰富的食物来源
there's a nutrient-rich supply of food
生命需要水
life needs water
还有食物和另外一样东西
it needs food and something else
生命还需要能量
you also need an energy source
地球的能量多半来自太阳
on the earth, mostly, that's the sun
阳光会温暖地球表面
it's light coming down and warming the surface
然而在木卫二的深海里
on europa, though, if you're deep in that ocean
或许是一片漆黑
it's probably pitch black
但是生命不需要光也能生存
but life can exist without the sun
如果你到地球的海底
if you go to the ocean floors on earth
海底的地壳会有喷口和裂缝
there are places where there are vents, cracks in the crust
那里会涌出气体和各种有毒化学物质
and gasses and all sorts of noxious chemicals
但是那种地方也有生命
are coming up, but there's life there
有一种想法是流动的营养物质
an ocean that there could be this flow of nutrients
可能从地表下方进入富含氧气的水中
from the sub-surface into an oxygen-rich water
这个中间地带可能会有生命
and life living at this boundary between them
目前我们就有这种实例
that's an example right in front of us
展示生态系统的确有可能这样形成
of how an ecosystem could be shaped that way
生命会随着它所处的环境
life evolves to match the conditions
而自我演化
in which it finds itself
木卫二的地下环境
the conditions under the surface of europa
跟地球的深海环境非常的相似
are very similar to the conditions at the bottom of the ocean here on earth
我们可能在那里找到生命
we may find life there
如果真的发现 它们应该和我们地球的深海生物很像
and if we do, it may look quite a bit like life under the ocean here on earth
如果在木卫二的地表下真适合生命
if there is life beneath europa's surface
他可能会事宜居住
it may outlive us all
这个荒凉世界可能成为我们太阳系生命的
this inhospitable world could become a last refuge
最后的避难所
for life in the solar system
因为50亿年后
because 5 billion years from now
太阳注定要死去
the sun is destined to die
木星以远超其他行星的方式
jupiter, more than any other planet
影响了我们太阳系的过去
has left its mark on our solar system
这颗最大的行星拥有最强的引力
the largest planet with the strongest gravity