地球的力量 第5集稀有行星(6):一起踏上征程

In some cases, they can only be seen with the latestmapping techniques,like this one in Brazil.

有時(shí)候需要專(zhuān)家的繪圖技術(shù) 才能揭示一個(gè)隕石坑的存在比如這個(gè)位于巴西的

But even with this technology,less than 200 impactcraters have been found across the entire planet.

但即使是用最精密的設(shè)備 在整個(gè)地球上 找到的隕石坑也不超過(guò)200個(gè)

This is partly because erosion continually rubs out the evidence of past impacts,

部分原因是因?yàn)楦g現(xiàn)象 不斷抹去過(guò)去沖擊的證據(jù)

but it's also because of the atmosphere's protective role.

但是也是因?yàn)榇髿鈱影l(fā)揮了保護(hù)作用

To understand how something as intangible as thin air protects us from meteors,

為了理解像空氣這樣薄稀的事物 如何保護(hù)我們不受隕石侵害

you need to find a meteorite that has survived its fall to Earth.

你需要尋找一個(gè)成功掉到地球上來(lái)的隕石

Meteorites are rare, so you need to go to great lengths to track one down.

隕石很稀少所以你需要費(fèi)很大的勁去尋找

Dr Phil Bland is a planetary scientist on just such a mission,

菲爾·布蘭德就是一個(gè)執(zhí)行該使命的科學(xué)家

leading an expedition out onto the barren NuHarbor Plain

我跟他一起踏上了征程

in Western Australia, three days' drive from the nearest town.

到澳大利亞西部有三天的車(chē)程