百科知識視頻之煎蛋小學(xué)堂31 地球之水哪里來？

Unlike every other planet in our solar system,Earth's surface is 70% liquild water,Which while useful for life,is also kind of weird,because everything we know about how and when our plannet formed,says Earth's surface should be bone dry.

與太陽系的其他行星不同，地球表面的70%都是水，這對生命正合適 但也很奇怪，因為一切我們所知的地球成因及時間 都表明 地球應(yīng)是極干燥的。

The story goes like this:our solar system formed from the collapse of large cloud of dust and gas.The dense blob of gas at the center ignited to form the sun,Which as a young,untable star unleashed a firrce solar wind.Over time this stream of charged particles pushed the remaining gas cloud farther and farther out,leaving only solid particles behind to clump together into rocks,planetesimals,and finally,the rocky planets of the inner solar system that we know today.

事情是這樣的;太陽系由一大片塵埃和氣體相撞形成。其中心最密集處開始燃燒 形成太陽，這個年輕 尚不穩(wěn)定的恒星釋放出了強勁的太陽風。漸漸地 帶電粒子流 將剩余氣體推到更遠處，使剩余的固體顆粒聚集形成巖石和星子，最終便是我們今日所知的 內(nèi)太陽系幾顆巖態(tài)行星。

And here's the problem :water,in the from of ice,couldn't have been one of the solid particles that stuck around before our planet,because the early inner solar system was far too hot for frozen wate,and any water vapor would have been blasted away by the solar wind.

問題在此 以冰的形成出現(xiàn)的水，不可能是太陽系形成前的一種固體顆粒 因為早期內(nèi)太陽系溫度遠高于冰水，任何水蒸氣亦都會被太陽風吹散。

So if Earth didn't start off with water,how did we end up with such splendid oceans? We know H20 wasn't manufactured here over the eons,because natural processes like combustion,breathing and photosynthesis create and destroy roughly equal amounts of water.And either way,the amounts in question are so miniscule that they can't account for the abundance of water on the planet.

那么 地球一開始沒有水 最終怎么會出現(xiàn)浩瀚海洋?我們知道 H20并非萬千年間形成于地球，因為諸多自然過程 如燃燒，呼吸和光合作用產(chǎn)生并消耗著等量的水。不管怎樣 它們的基數(shù)太小 不可能解釋地球如此豐富的水量。

Since Earth's water was neither part of the original package nor manufactured here,It must have flown in from far away,on meteoroids or comets or other bodies originating in the outer solar system,where they were far enough from the Sun for frozen water to survive.The dirty iceballs that the we call comets are a logical candidate for the source of our water,But were ruled out when we discovered that they are far richer in heavy hydrogen than Earth water.Heavy hydrogen has a neutron as well as a proton in is nucleus,and for every million hydrogen atoms in Earth water,about 150 are heavy ones,while typical comet water has twice that many.

由于地球的水并非起源于此 或產(chǎn)生于此，它肯定是從遠方流入的 從隕石或彗星 或者他外太陽系天體來 在那里 它離太陽夠遠 能讓水保持凍結(jié)。那些臟冰球 即“彗星” 是水的來源的合適候選者之一。但已被淘汰 當我們發(fā)現(xiàn) 其重氫含量比地球上的水高得多。重氫的原子核中有一個中子和一個質(zhì)子，地球水中 每一百萬個氫原子中就有150個是重氫，而一般彗星水是它的兩倍。

These mismatched chemical signatures suggest that Earth's water could not have arrived on comets.It turns out that the most likely source for Earth's water is a type of meteorite called a carbonaceous chondrite."Chondrite"is just the name given to the class of stony meteoroids that most commonly strike the Earth.But only the carbonaceous chondrites contain water as well as lots of carbon,if you couldn't tell from their name.

這些不相符的化學(xué)標志表明 地球的水不可能來自于彗星。結(jié)果證明 地球水最可能的來源 是一種被稱為碳質(zhì)球粒隕石的隕石。“球粒狀隕石”只是那些常襲擊地球的巖類流星體的名字。但只有碳質(zhì)球粒隕石中含有水 以及大量的碳 如果你沒從名字里發(fā)現(xiàn)的話。

They have water in then because they formed out beyond the sun's"frost line",and what's more,their water has levels of heavy hydrogen similar to that of earth water,strongly suggesting that these earth-crashers, are the source of our ice caps,clouds,rivers,and oceans.

它們含水 因為它們形成于太陽的“冰凍線”外，另外 其水中的重氫含量和地球水相似，強有力的證明了 這些地球的不速之客 是我們冰蓋 云層 河流和海洋的來源。

And thus the water that turned our planet into a blue marble came,quite literally,out of the blue.

因此 把我們星球變成藍色大理石的水也來自，文字上說是 蔚藍深處。