未登录,请登录后再发表信息
最新评论 (0)
播放视频

我们是怎么知道其他星球上的空气成分的?

How Do We Know What Air is Like on Other Planets?

我们都知道木星的大气主要是由氢和氦组成 木星的

We know that Jupiter has an atmosphere made up mainly of hydrogen and helium. Europa,
一颗卫星 Europa 有很薄的氧气层HD 209458 b是和木星一样大的
a moon of Jupiter, has a very thin oxygen atmosphere, and HD 209458 b, a Jupiter-sized
行星 绕着恒星HD 209458旋转距太阳系154光年 大气成分包括
exoplanet orbiting the star HD 209458 which is 154 lightyears away, has an atmosphere
氢 碳 氧 钠 二氧化碳 甲烷和甚至还有水蒸气
that contains hydrogen, carbon, oxygen, sodium, carbon dioxide, methane, and even water vapor.
我们即使没有去这些地方直接进行空气取样
All this even though we haven’t visited any of these places to directly sample the
而我们也不必那么做
air… but we don’t need to.
我们用其他星球的卫星就能研究外星系的大气成分了

We can study the air on other planets, moons, and exoplanets just by looking at them. In
特别是通过光的反射或者是光穿过大气的过程
particular, by looking at light that bounces off or passes through their atmospheres, because
因为阳光照射到气体上时分子的吸收和散射频率是
when you shine light on a gas, the molecules absorb and scatter different frequencies of
不一样的 如果我们把透射或散射的光
that light in different amounts. If we then split the transmitted or scattered light apart
用菱镜或衍射光栅进行颜色分层就会看到分子的

into its constituent colors using a prism or diffraction grating, we can see a molecule’s
光吸收纹路或者发光纹路这种是氢 这种是氮
light-absorption fingerprint, or its light-emission fingerprint. This is hydrogen. This is nitrogen.
还有氧气 甲烷 二氧化碳 水分 硫酸
Oxygen. Methane. Carbon dioxide. Water. Sulfuric acid.
那么当我们看到星球大气的阳光反射就可以用
So when we look at the sunlight bouncing off of the atmospheres of planets and notice spikes
频率来定位高度我们就能仔细匹配那些
of certain heights in certain frequencies, we can carefully match those to the known
已知的气体分子纹路 这样不止可以知道空气的组成
fingerprints of gas molecules, and learn not just what gases make up the air, but even
还有其他很多的相关信息
their relative abundances!
所以事实上 我们完全不必亲眼看到星球来了解大气组成
In fact, we don’t even need to be able to see a planet at all to learn about its atmosphere
很多外星系都是因为它们穿过母星时
– many exoplanets have been discovered because they pass in front of their parent
就是我们看到整个星球的亮度下降的时候

star, which we see as a dip in the overall intensity of the star’s light. But if an
但是如果一颗外系星球有大气 它的大气中的气体分子会阻挡部分
exoplanet has an atmosphere, the gas molecules in its atmosphere will block some frequencies
频率的光 根据分子纹路我们就能像之前一样做气体
an extra amount, according to their molecular fingerprints, and we can do the same gas-matching
颜色匹配 这就是我们了解HD 209458 b星大气组成的方法
process as before. And that’s how we know what’s in the atmosphere of HD 209458 b!.
当然了 用纹路匹配这种方法来判断外系星球大气组成
Of course, in practice it’s pretty darn challenging to use molecular fingerprints
还有待商榷 因为空气稀薄的话纹路就会非常微弱
to study exoplanet atmospheres, because air is thin so the fingerprints are super faint
我们需要更加灵敏的望远镜和光谱分析仪而且由于大气构造很复杂
and we need big sensitive telescopes and spectrometers; and because atmospheres are complicated and
它的纹路也可能模糊不清或者难以匹配而且因为不同的星球
their fingerprints can be ambiguous or hard to match; and because different parts of a
会发出不同颜色程度的光所以一颗星球的
single star emit different amounts of different colors of light, so a planet’s effect on
影响范围取决于星球经过木星的部分
the star’s spectrum will depend on which part the planet passes in front of.
不过所有的难题都会被机智的天文学家解决也因此我们
But all of these difficulties can be dealt with by clever astronomers, and thus we have
才能知道 距我们几百光年外 看不见的星球的
been able to figure out what the air is like on planets hundreds of light years away that
大气组成情况
we can’t even see.

发表评论

译制信息
视频概述
听录译者

收集自网络

翻译译者

【LR】Fanny

审核员

自动通过审核

视频来源

https://www.youtube.com/watch?v=UfJ-i4Y6DGU

相关推荐