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DNA的组成部分来自外太空?

Scientists Say DNA's Building Blocks May ACTUALLY Come From Outer Space

It was almost 11 o’clock in the morning on the 28th of September 1969
那是1969年9月28日上午将近11点
when above a small rural town in south-eastern Australia
澳大利亚东南部一个乡下小镇的上空
a fireball was seen flying through the sky.
划过了一个火球
That fireball broke off into three parts
火球裂成了三部分
and left behind a cloud of smoke.
留下了一团烟雾
Half a minute after that a tremor could be heard.
半分钟后 人们感受到一场地颤
This was when something called the Murchison meteorite hit our fair planet.
这就是默奇森陨石撞击我们美丽的地球时的情景
That rock broke off into lots of fragments
这块陨石碎裂成很多碎片
with one bit going right through a roof and landing in some hay.
有一小块直接穿过屋顶落在干草上
The total weight of all the bits that were found
被发现的碎片的总重量
was almost 220 pounds (100 kilograms).
将近220磅(100千克)
It became one of the most studied meteorites ever,
它成为了被研究最多的陨石之一
and one of the reasons why was that it contained lots of organic compounds.
其中一个原因是它含有很多有机化合物
The question scientists have been asking since then is
自那时起 科学家们一直存在着疑惑
did life on Earth come from outer space?
地球上的生命来自外太空吗?
Some theories state that life on Earth started in something
一些理论认为 地球上的生命起源于
referred to as the primordial soup.
一种叫原始汤的东西
This soup contained organic molecules,
原始汤含有有机分子
and those include amino acids, which are the building blocks of proteins.
而有机分子包含了组成蛋白质的氨基酸
There are plenty of theories as to how life got there.
世上有很多关于生命是如何形成的理论
But scientists agree that the soup was left in the pan for many millions of years
但科学家们认为 原始汤在地球上留存了几百万年
and eventually complex life forms were created.
最终形成了复杂的生命形式
We’ve done an entire show on why you exist at all
我们已经做了一个关于你为什么存在的完整节目
suffice it to say,it’s a complex matter.
无须多说 这是一个复杂的问题
Today we’re going to concentrate only on meteorites that might have carried life here.
今天我们将只关注可能携带生命的陨石
A meteorite is part of a meteor
陨石是从流星中碎裂出的一部分
that breaks off and doesn’t burn up before it gets to Earth.
在到达地球之前 它不会燃尽
A comet is a chunk of ice and rock
彗星由大量的冰和岩石组成
that moves through space, often with a tail behind it.
通常拖着一条尾巴在太空里划过
An asteroid is large piece of rock
小行星是大块的岩石
that usually orbits between Mars and Jupiter
通常围绕火星和木星之间运动
but sometimes gets thrown off course.
但有时会偏离轨道
A meteor is a rock that burns up.
流星是燃烧的岩石
And this is why they are sometimes called a shooting star or a falling star.
这就是它们有时被称作“陨星”的原因
Meteorites are the rocks that actually get here,
陨石是真正到达地球的岩石
hence we can look closely.
因此我们可以近距离地观察它们
Researchers have for many years been looking closely at the one
研究者耗时多年近距离观察
that hit Australia in many pieces.
击中澳洲并且四分五裂的那块陨石
In 2010, the Scientific American wrote about new research
2010年 《科学美国人》发表了一篇新研究
which revealed it contained millions of distinct organic compounds,
揭示了陨石含有数百万种不同的有机化合物
and that it was far more complex than first thought.
而且陨石比最初认为的要复杂很多
At the time, scientists were still trying to work out just what the meteorite contained,
当时 由于陨石的复杂性 科学家们仍在努力研究
since it was not straightforward.
它到底含有什么物质
One researcher said:”It’s exciting, but it also scares me at the same time.
一位研究者说:“这很令人兴奋 但同时也让我害怕
We have a lot of work to do to even pretend to understand what this stuff is.”
即使是假装理解这个东西 我们也要做大量的工作”
A few years later, a planetary scientist at the University of Chicago
几年后 芝加哥大学的一位行星科学家
and a NASA astrophysicist got together to do an experiment.
和美国航空航天局的一位天体物理学家一起做了一个实验
The Smithsonian explained that
史密森尼学会解释说
those scientists created a computer model of the solar nebula.
这些科学家创建了太阳星云的计算机模型
This is the gaseous cloud from which it’s theorized our solar system was formed.
这是气态云 是太阳系形成的理论基础
That was way back in 4.6 billion and a bit BC.
那是公元前四十六亿年左右
Their debris in the model consisted of 5,000 icy grains moving about for millions of years.
模型中的碎片由5000多个移动了数百万年的冰颗粒组成
That’s simulation of course, not actually millions of years.
当然这只是模拟 不是真的数百万年
Within these grains were water, carbon dioxide, ammonia and other moleculesn,
这些颗粒中有水 二氧化碳 氨和其他分子
their computer model revealed that
计算机模型显示
when irradiated by the sun in this experiment, something profound happened.
当受到太阳辐射时 一些意义深远的事情发生了
The Smithsonian writes, “High-energy ultraviolet radiation broke molecular bonds,
史密森尼学会写道:“高能紫外线将分子键打碎
creating highly reactive atoms that were prone to recombine
形成了高活跃的原子 从而易于重新结合
and form more stable, and sometimes, more complex compounds.”
形成有时更复杂的更稳定的化合物
The process could’ve created organic compounds and with that proteins, RNA and DNA.
这个过程产生有机分子 随后是蛋白质 RNA和DNA
The theory those scientists came to was that
这些科学家得出的理论是
possibly those organic compounds made their way into the rocks in the early universe,
这些有机化合物可能在宇宙早期进入了岩石
some of which later got together to form planets,
其中一些岩石后来聚在一起形成了行星
such as the one you’re sitting on now.
比如你现在所处的地球
They might have also been part of other rocks such as comets or meteorites
这些岩石也可能是彗星或陨石的一部分
that at some point made a splash in Earth’s primordial soup.
在某个时刻溅落在地球的原始汤中
Scientists explain that because of Jupiter’s gravity
科学家解释称 由于木星的重力
some of those things called planetesimals couldn’t join and form a proper planet.
有些被称为星子的岩石不能真正结合并形成行星
Planetesimals could be said to be very small bodies of rock and dust,
星子可以说是由岩石和尘埃组成的
which measure over 1km in diameter.
直径超过一千米的非常小的天体
But Jupiter’s gravity forced them to smash together
但木星的引力迫使它们相撞
and this formed a massive asteroid belt.
形成了一个巨大的小行星带
From this asteroid belt smaller rocks might have travelled to Earth.
小行星带中较小的岩石就可能运动到地球
What’s interesting about this is that if life on Earth did come from these rocks,
有趣的是 如果地球上的生命真的来自这些岩石
then they might have carried life to other planets
那么在相同的条件下
outside our solar system if the same conditions were present.
它们也可能将生命带去太阳系外的其他星球
Now fast-forward to 2019 and listen to what some NASA scientists
现在快进到2019年 看看美国航空航天局的科学家
and some Japanese academics had to say about what they found in two meteorites.
和一些日本学者在两块陨石中发现了什么
They discovered something called ribose,
他们发现了一种叫做核糖的物质
which is a sugar found in RNA and DNA.
它是一种存在于RNA和DNA中的糖
Why is this important?
为什么这很重要呢?
Well, We’ll let one of the Japanese researchers explain.
其中一位日本研究者解释说
He said: “The research provides the first direct evidence of ribose in space
“这项研究提供了核糖在太空存在
and the delivery of the sugar to Earth.
并输送到地球的首个直接证据
The extraterrestrial sugar might have contributed to the formation of RNA on the prebiotic Earth
来自外星的糖可能促成了生物起源前地球上RNA的形成
which possibly led to the origin of life.”
这可能导致了生命的起源”
They say possibly, nothing is certain just yet.
他们说这只是可能 现在不能确定什么
On NASA’s own website it states that
在美国航空航天局的网站上有声明说
the discovery of ribose in a meteorite
陨石中发现的核糖
is just the latest of important compounds found in those things,
是陨石中最新发现的重要化合物
adding to the list of what we have already talked about.
加上我们之前讨论过的陨石问题
When big rocks broke and then smaller ones hit Earth,
当大岩石断裂成小岩石撞击地球时
they could’ve been carrying the essential ingredients that would in the end make us.
它们可能携带着创造生命必不可少的原料
NASA explained that the messenger molecule, RNA,
美国航空航天局解释道 信使分子RNA
copies genetic instructions from the thing we know as DNA.
从DNA中复制遗传指令
The point is to deliver messages to cells that read the message and build proteins.
重点是把信息传递给能读取信息并制造蛋白质的细胞
That’s how things are made in the life business.
这就是创造生命的过程
The researchers explained that
研究者解释
the new discovery gives a lot more credence to the theory of
这项新发现让人们更加相信了
life not bubbling up through vents underwater to reach the primordial swamp,
生命不是通过水下喷口冒出来到达原始沼泽
but something that hit the swamp from space.
而是通过来自太空物体的撞击来到沼泽里的理论
NASA wrote on its website:
美国航空航天局在它的网页上写道
“Other important building blocks of life have been found in meteorites previously,
“之前在陨石中也发现了生命的其他重要组成部分
including amino acids (components of proteins)
包括氨基酸(蛋白质的成分)
and nucleobases (components of DNA and RNA),
和碱基(DNA和RNA的成分)
but sugars have been a missing piece among the major building blocks of life.”
但是糖一直是生命的主要组成部分中缺失的一块”
So, maybe this was the missing part of the puzzle.
所以 也许这就是谜团中缺失的那部分
Just some sugar was needed to make conditions sweet enough for life to arise.
有了这些糖 就能达到生命诞生的条件
More research needs to be done and other rocks need to be studied.
我们还需要做更多的探索 研究更多的岩石
NASA was also quick to say that
美国航空航天局很快表示
the sugars in the meteorites could have come from down here.
陨石中的糖也可能来自地球
They might have been contaminated by life already here.
它们可能已经被本就在这里的生物污染了
The agency, however, thinks that this is unlikely after analyzing the rocks.
然而 在分析了这些岩石后 他们认为这是不可能的
It’s still up for debate, but the next video you need to watch definitely isn’t.
这仍然是有争议的 但下一个视频绝对没有争议
Go watch our incredible video
去看看我们的精彩视频
“Astronomers Are Speechless After Spotting THIS Inside Black Hole”
“使天文学家哑口无言的黑洞内部现象”
right now for more insane space mysteries!
去追寻更加疯狂的太空奥谜吧!

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视频概述

生命的起源有很多种假说,那么我们是否可能完全来自于外太空呢?这要从科学家对一块陨石的研究说起……

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视频来源

https://www.youtube.com/watch?v=wiPZovylSvk

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