評論
打印
How big an asteroid would it take to distribute this much Iridium around the entire planet?
到底要多大的小行星才能將這么多銥散布在整個星球上？
And they come up with a very rough number of something on the order of ten kilometers across, that's, you know, it's Mount Everest size sort of impact, if you will.
他們提出了一個粗略的數據，大概是10千米直徑的東西，要知道這大小可是相當于埃佛勒斯峰了。
But if an asteroid the size of Mount Everest destroyed the dinosaurs, where was the crater?
不過要是埃佛勒斯峰那么大的小行星毀滅了恐龍，那隕石坑在哪里？
For ten years, the mystery remained.
十年間謎團依舊。
Then, in 1990, a clue emerged.
之后，在1990年一條線索浮現了。
Searching for oil in the Yucatan peninsula, geologists came upon an evidence of a massive underwater impact.
在尤卡坦半島進行石油勘探時，地質學家們發現了一個巨大的水下沖擊的證據。
There was an oil company in Mexico, searching for different places where there might be oil deposits.
在墨西哥有一家石油公司，在不同地方尋找可能儲藏石油的地方。
And in those areas they actually found a fairly circular feature, and in that, they deduced that that might be an impact crater.
他們在那些區域發現了相當圓的地形，就這樣他們推測那可能是個撞擊坑。
The satellite images were mind boggling.
衛星圖像更是讓人震驚。
And then they started to see the telltale signs that something very big and very large had hit.
在那時他們開始看到一些能說明問題的跡象，地球被非常巨大的物體擊中過。
And now finally, what's happened just recent times, is we have radar information from the Space Shuttle, and from that you can actually see the outlines, very faintly, of this impact crater.
現在終于，在不久之前從航天飛機上獲得了雷達信息，從上面能夠隱約看到這個撞擊坑的輪廓。
This huge crater is called the Chixalube crater.
這個巨大的隕石坑被稱作奇科蘇盧布隕石坑。
It needed to be the right size to be linked to the K-T boundary evidence.
要與KT界限層的證據連接起來，它的大小必須合適。
It wasn't until 1990,1991 when the Chixalube crater in Northern Yucatan was identified.
直到1990年、1991年，尤卡坦半島北部的奇科蘇盧布隕石坑才被發現。
Most people felt pretty confident that, that crater was 180 kilometers across based on the most prominent set of circular features there.
多數人很確信，那個隕石坑直徑達180千米，這是據最主要的一層環狀結構測量所得。
A 180 kilometer crater, that's 111 miles across.
180千米的隕石坑，就是直徑111千米。
Looking backwards, what size asteroid could create a crater of that magnitude?
反過來看看，多大的小行星才能產生如此規模的隕石坑呢？
So how big an impactor would it take to make a 180-kilometer diameter crater on the earth?
多大的撞擊物才能在地球上留下直徑180千米的隕石坑呢？
Well, at the typical speeds that asteroids will strike the earth you know, of order 20 kilometers per second, the answer comes back an asteroid, you know,
小行星撞擊地球的典型速度是每秒20千米，答案回到一個直徑大約10千米小行星，
about ten kilometers across and that's perfectly consistent with the original estimate from the concentration of Iridium that the Alvarez's independently calculated a decade previously.
那與原始的估計完美地一致，原始的估計來自阿爾弗雷茲十年前對銥含量的獨立計算。
This evidence was overwhelming.
這是壓倒性的證據。
An asteroid about the size of Mount Everest, had struck the earth in the Yucatan Peninsula at the end of the Cretaceous period, 65 million years ago.
大小如同埃佛勒斯峰的小行星，在六千五百萬年前白堊紀末期于尤卡坦半島撞擊到地球上。
Dr. William Bottke, assistant director of space studies at the Southwest Research Institute, then went even further.
威廉·波特克博士是西南研究院太空研究部的助理主任，他的研究更進一步。
His research pointed to the Baptistina asteroid fragments, from the deep space collision 250 million years earlier.
他的研究指向巴蒂斯緹娜小行星碎片，它們來自此前兩億五千萬年前的深空撞擊。
And it showed that the earth wasn't Baptisina's only victim.
而且有證據表明地球不是巴蒂斯緹娜的唯一受害者。
An asteroid also struck the moon, triggering a landslide.
一顆小行星也撞到了月球，導致了山崩。
The Apollo 17 spacecraft, landed in a place, where they actually detected evidence for a landslide that had happened about 110 million years ago.
阿波羅十七號宇宙飛船，在降落位置探測到了山崩的證據，發生的時間是一億一千萬年前。
They believe this landslide was triggered by a cratering event on the other side of the moon.
他們相信這次山崩是月球另一側一次撞擊事件所導致的。
Not only it's very large, it's well over 80 kilometers or so, but it's also surprisingly young, it would have this age of 110 million years.
它不僅非常大，直徑達約80千米，而且年輕得驚人，其年齡僅僅為一億一千萬年。
We find there's a very high probability, well over 70%, that this particular crater, was produced by the Baptistina fragments.
我們發現有很大可能，超過百分之七十，這個隕石坑是巴蒂斯緹娜碎片造成的。
An asteroid storm blasted the solar system.
一次小行星風暴轟擊太陽系。
One struck the moon.
一顆擊中月球。
Another was on a collision course with prehistoric earth with horrifying results.
另一顆的軌道與史前地球交匯帶來可怕的結果。
Traveling at twice the speed of sound, an enormous asteroid made its way into our inner solar system, on a collision course with the dinosaurs.
一顆巨大的小行星以音速兩倍的飛行速度，迎頭闖進我們的內太陽系，將要撞擊到恐龍的世界。
65 million years ago, the earth suffered an enormous extinction event, one that would wipe out all the non-avian dinosaurs, along with millions of other life forms.
六千五百萬年前，地球遭受了一次重大滅絕事件，這次滅絕事件消滅了所有的非鳥類恐龍，以及數百萬其他生物。
Imagine a rock, the size of Manhattan Island, slamming into the earth at 43,000 miles per hour.
想象一下一塊像曼哈頓島一樣大的石頭，以時速近43,000英里撞到地球之上。
You've heard of the phrase hell on earth?
聽說過人間地獄嗎？
This impact was so powerful hell would have felt like a tanning booth in comparison.
這次撞擊力量太強大，地獄與之相比就像是小兒科。
In 2000, another link was found between the asteroid and prehistoric earth.
在2000年，小行星和史前地球的另一個聯系也被發現了。
Several years ago, there was a service, they went out, and actually took cores, from different places in the ocean.
幾年前，曾有過一些調查，人們在大洋的不同位置，進行巖芯采樣。
And they tried to probe, to get, these cores all way back to 65 million years ago.
他們試圖探測獲得六千五百萬年前的巖芯。
And interesting enough in one of these probe, in one of these core samples, they found a tiny piece of a meteorite, a fossil meteorite.
在這些探測中非常有趣的是，在一個巖芯樣本里他們找到了一小塊隕石，化石隕石。
And the composition of that meteorite, is very consistent with the composition of Baptistina.
那個隕石的成分，與巴蒂斯緹娜其實非常一致。
So, it's not just dynamics, but it's also this link, with the chemistry.
所以不僅有動力學證據，在化學成分上也有聯系。
The impact of the asteroid would kick start a series of cataclysmic events that would devastate life on earth.
小行星的撞擊會引發一系列災難事件，重創地球上的生命。
