了解宇宙是如何运行的（2010）

How the Universe Works S11E01

Part 6 April 10, 2023, 10:19 a.m.

ROWE: A clue comes from
the rings' composition.
它们大约99%是水冰
They're around
99 percent water ice,
它们大约99%是水冰
They're around
99 percent water ice,
这让光环看起来闪闪发光
giving the rings
their sparkling appearance.
这让天文学家提出了一个大胆的理论
This leads astronomers
to a bold theory.
我们不知道土星的冰环是如何形成的
We do not know how Saturn's
icy rings formed.
我们甚至不确定它们的年龄
We're not even sure
how old they are,
但有一种想法是，它们是由
but one idea is that
they formed from ice that was
以前存在于卫星上的冰形成的
existing previously on a moon.
这太神奇了
How amazing is that?
几十亿年前，土星可能是没有光环的
ROWE: Several billion years ago,
Saturn may have been ringless,
只有一颗巨大的冰质卫星
with a large, icy moon.
只有一颗巨大的冰质卫星
with a large, icy moon.
卫星足够大，它的引力将岩石等较重的物质
The moon was big enough that
its gravity drew heavier
吸引到它的核心
stuff like rock to its core
而冰等较轻的物质则漂浮到顶部
and lighter stuff like ice
floated to the top.
我们认为卫星离土星太近了
ROWE: We think the moon
strayed too close to Saturn.
沃尔什:来自土星的引力会把它撕裂
WALSH: The gravity from Saturn
could tear it apart,
它会把冰从岩石部分分离出来
and it could separate the ices
from the rocky parts
冰会留在轨道上形成土星环
and the ices could stay in
orbit and form our rings,
岩石部分会被土星吞噬
and the rocky parts would get
swallowed up by Saturn.
岩石部分会被土星吞噬
and the rocky parts would get
swallowed up by Saturn.
一颗大卫星的消亡可能形成了土星环
The death of a large moon
may have built the rings,
但它们现在的样子要归功于
but they owe their current
appearance to the moons that
那些仍然活着的卫星
are still alive.
塞勒:当你一次又一次地
THALLER: When you go back
to Saturn's rings,
回顾土星环时,它们都略有不同
time and time again,
they're all slightly different.
它们在变化，彼此交织在一起——
They are changing, they are
braiding in and out of
我们不知道光环
each other -- we had no idea
there would be
我们不知道光环
each other -- we had no idea
there would be
会有如此的美丽和如此的神秘
so much beauty and so much
mystery in the rings.
土星的两颗卫星
ROWE: The behavior of two of
Saturn's moons,
普罗米修斯和阿特拉斯
Prometheus and Atlas,
镶嵌在土星环中
which are embedded in
the rings
它们的行为尤其令人惊讶
is especially surprising.
这些最小的卫星中有一些
Some of these smallest moons
散布在光环系统中
are interspersed within
the ring system.
他们中的一些正在做一些非常奇怪的事情
Some of them are doing
something really bizarre.
在某些情况下，这些卫星看起来像是在守护着
In some cases, it looks like
the moons were shepherding
在某些情况下，这些卫星看起来像是在守护着
In some cases, it looks like
the moons were shepherding
光环的边缘，并让它们保持在自己的位置上
the edges of the rings and
keeping them in their place.
卫星的引力会清理这些环
ROWE: The moon's gravity
cleans up the rings,
有时会在它们的尾迹上雕刻出形状
sometimes, sculpting shapes
in their wake.
土星环不是静止的，有一些非常迷人的
Saturn's rings aren't static,
and there's some really
相互作用，卫星显然在推动土星环
fascinating interactions where
moons are clearly pushing on
并产生奇怪但又很酷的波浪
the rings and causing weird
and cool waves,
使土星环更加美丽
making the rings just
that much more beautiful.
豪威特:土星和它的卫星、土星环之间的
HOWETT: The whole dance between
Saturn and its moons,
整个“舞蹈”
its rings,
how they all
以及它们是如何相互联♥系♥的，完全令人着迷
are interconnected, is just
completely fascinating.
这是一个充满活力
It's a dynamic, amazing,
令人惊叹、生机勃勃的地方
living, geologically
vibrant place.
土星的卫星也许能让土星环保持有序
ROWE: Saturn's moons may keep
the rings orderly,
但它们无法解释为什么土星环如此干净
but they can't explain
why the rings are so clean,
几乎是原始的
almost pristine.
普拉特:他们太亮了
PLAIT:
They're too shiny.
如果它们有数十亿年的历史
If they were billions of
years old,
那么它们现在应该聚集了大量的灰尘
they should have collected
a lot of dust by now
颜色也会深得多
and be a lot darker.
它们闪闪发光的事实暗示着
The fact that they're shiny
kind of implies that
它们可能比我们最初想象的要年轻得多
maybe they're a lot younger
than we first thought.
也许我们今天看到的这些光环
ROWE: Perhaps
the rings we see today
是最近才生成的
are a more recent upgrade.
这些环可能只有1亿年的历史
The rings might only be
100 million years old,
大约是恐龙的时代生成的
about the time of
the dinosaurs.
所以如果恐龙发明了望远镜
So if the dinosaurs
had invented telescopes,
所以如果恐龙发明了望远镜
So if the dinosaurs
had invented telescopes,
他们就能看到没有光环的土星
they could have seen Saturn
without rings.
这不由得让人猜想
And it makes you wonder,
is this
这是土星的第一个环系吗？
the first ring system that
Saturn had?
或者还有另一个
Or was there another
ring system
可能被慢慢侵蚀的环系？
that may be slowly
eroded away?
也许是一颗彗星或一颗天体离土星太近了
Perhaps a comet or a body came
in too close to Saturn,
土星的引力真的把它撕裂了
and Saturn's gravity
literally tore it apart,
然后我们得到了一个全新的环系统
and then we got a brand-new
ring system.
后来的恐龙可能目睹了环的形成
The later dinosaurs could have
watched the rings form,
然后它们就被小行星消灭了
and then they would have been
wiped out by an asteroid.
是的，应该造更好的望远镜
Yeah, should have built
better telescopes,
是的，应该造更好的望远镜
Yeah, should have built
better telescopes,
恐龙，你真差劲
dinosaurs, sucks to be you.
我们仍然不知道为什么土星环
ROWE: We still don't know
why the rings of Saturn
如此干净
are so clean.
有可能这些环真的很古老
It could be that the rings
really are old, and they have
它们有某种清洁系统
some sort of cleaning system,
可以清除上面的灰尘
which removes the dust
from them,
让它们看起来很年轻,或者它们实际上很年轻
making them look young, or they
may actually be young, and this
这可能是第七代，第八代或任何一代的环
may be the seventh or eighth
or whatever generation rings.
它与其他行星系统截然不同
It is so different than
any other planetary system.
它与其他行星系统截然不同
It is so different than
any other planetary system.
这些谜团仍然存在
And those mysteries
still exist.
我们知道发生了什么
We have some idea
what went on,
但关于土星还有很多我们不知道的
but there's a lot that
we don't know about Saturn.
卡西尼号♥正在改变这一点