When you think of space, you usually think of an endless place with unbelievable distances between stars.

當你想到太空時，你通常會想到一個無盡的地方，恆星之間有著不可思議的距離。

Though, the fact of the matter is that the vast majority of human activity in space for far has taken place in a narrow slice just 2,000 kilometers above the Earth's surface.

雖然，事實上，迄今為止，人類在太空中的絕大部分活動都是在距離地球表面僅有2000公里的狹長地帶進行的。

Known as Low-Earth-Orbit, or LEO for short.

被稱為低地軌道，簡稱LEO。

This area contains the International Space Station and over 2,000 government and commercial satellites that provide everything from television signals, GPS, weather forecast, and much more.

這個區域包含了國際空間站和2000多顆政府和商業衛星，提供從電視信號、全球定位系統、天氣預報等一切服務。

However, in addition to all of these incredible technological achievements, humanity has also created a very large problem that cannot only, completely undo all of this progress, but also prevent us from visiting space again for several generations.

然而，除了這些令人難以置信的技術成就，人類還製造了一個非常大的問題，不僅不能，完全抹殺所有這些進步，而且還會阻止我們幾代人再次訪問太空。

In addition to space stations and satellites, LEO is home to tremendous amounts of garbage and debris we've been throwing out ever since we first started visiting space.

除了空間站和衛星之外，低地球軌道上還有大量的垃圾和碎片，自從我們開始訪問太空以來，我們就一直在扔垃圾。

Most of this junk consists of tiny objects like dust from solid rocket motors, flakes of paint eroded off of vehicle surfaces, or leaked frozen coolant from nuclear satellites.

這些垃圾大多由微小的物體組成，如固體火箭發動機的灰塵、車輛表面被侵蝕的油漆片，或核衛星洩漏的冷凍冷卻劑。

Whatever the source, it is estimated that there are over 100 million tiny pieces of junk less than one centimeter wide currently zipping around the Earth at speeds of 22,000 kilometers per hour(13,670 miles per hour) or faster

無論來源是什麼，據估計，目前有超過1億塊不到一釐米寬的小垃圾以每小時22,000公里（每小時13,670英里）或更快的速度在地球上飛馳。

If that doesn't sound like much, this image here is the aftermath of one of these flecks of paint that struck the front window of the Space Shuttle Challenger in 1983

如果這聽起來沒什麼，這裡的這張圖片是1983年挑戰者號航天飛機前窗上的這些斑點油漆的後果。

In addition to the small stuff in LEO however, there are also an estimated 500 thousand pieces of junk between 1 centimeter and 10 centimeters wide.

不過，除了低地軌道上的小東西，估計還有50萬件寬1釐米到10釐米的垃圾。

All of this stuff mindlessly orbiting around the Earth will eventually result in collisions between them at extremely high velocities.

所有這些東西無意識地圍繞地球運行，最終會導致它們之間以極高的速度發生碰撞。

Which creates a large number of new fragments, these fragments will then go on to eventually collide with other objects, which creates even more fragments, which will inevitably collide even more objects and SO ON AND SO ON.

這就產生了大量新的碎片，這些碎片最終會去碰撞其他物體，這就產生了更多的碎片，而這些碎片又必然會碰撞更多的物體，如此循環往復。

Until we enter the Kessler Syndrome, a hypothetical future scenario first proposed by Donald J. Kessler back in 1978.

直到我們進入 "凱斯勒綜合症"，這是唐納德-J-凱斯勒在1978年首次提出的一種假設性的未來情景。

Since it can take years, decades, or even centuries for space junk to enter into Earth's atmosphere and burn up on its own.

由於太空垃圾進入地球大氣層並自行燃燒可能需要幾年、幾十年甚至幾百年的時間。

When we lose something in space it generally sticks around for a pretty long time.

當我們在太空中失去一些東西時，它一般會停留相當長的時間。

These random collisions between fragments in space could eventually result in so many tiny fragments traveling at insanely high speeds,

這些空間中碎片之間的隨機碰撞，最終可能會導致這麼多微小的碎片以瘋狂的速度旅行。

The Low-Earth-Orbit would effectively be like a constant shooting range.

低地軌道將有效地像一個恆定的射擊場。

In the worst case scenario, all currently existing satellites in LEO would be destroyed into millions of tiny pieces.

在最壞的情況下，目前低地球軌道上的所有衛星都將被摧毀成數百萬個小碎片。

Launching any new mission into space from Earth's surface would be destroyed almost immediately by these pieces.

從地球表面向太空發射任何新的任務，幾乎會立即被這些碎片摧毀。

Rendering any space mission in the future a suicide mission

使未來的任何空間任務都成為自殺式任務

We would lose all the technology that satellites provide to us and several generations would be robbed of the promise of space travel while we wait patiently for the garbage to get rid of itself naturally.

我們將失去衛星為我們提供的所有技術，幾代人將被剝奪太空旅行的承諾，而我們卻在耐心地等待垃圾的自然清除。

So, is the Kessler Syndrome inevitable?

那麼，凱斯勒綜合症是否不可避免呢？

Back in 2009, a defunct Russian military satellite collided with an operational US commercial satellite, which shattered both into thousands of different tiny fragments

早在2009年，一顆已失效的俄羅斯軍用衛星與一顆正在運行的美國商業衛星相撞，兩者都碎成了成千上萬個不同的微小碎片。

This is the most significant unintentional collision has so far happened, but an intentional collision in 2007 created even more fragments. (Andrew N: I'm done here.)

這是到目前為止發生的最重大的一次無意碰撞，但2007年的一次有意碰撞造成的碎片更多。(安德魯-N：我在這裡說完了。)

In that year the chinese government tested an anti satellite missile by using one to destroy one of their own satellite in LEO

在那一年，中國政府測試了一枚反衛星飛彈，用它摧毀了他們自己在低地軌道上的一顆衛星。

This event produced over 2,000 golf ball sized or larger fragments as well as over 150,000 tiny debris particles

這次事件產生了2,000多個高爾夫球大小或更大的碎片，以及15萬多個微小的碎片顆粒。

In 2011, some of the debris from this test passed a mere 6 kilometers away from the international space station

2011年，這次試驗產生的一些碎片在距離國際空間站僅6公里的地方通過。

One of the most dangerous potential triggers of a Kessler syndrome in LEO is the now defunct ENVISAT satellite launched by the European Space Agency in 2002

歐洲航天局2002年發射的現已停用的ENVISAT衛星是低地球軌道上凱斯勒綜合症最危險的潛在誘因之一。

Contact was lost with the satellite in 2012 and now the 8000 kilogram piece of junk gets passed within 200 meters by two other catalog pieces of space junk every year

2012年與衛星失去聯繫，現在這顆8000公斤重的垃圾每年都會被另外兩顆目錄中的太空垃圾在200米範圍內穿過。

Since ENVISAT will likely remain in orbit around Earth for the next 150 years and the rate of collision is expected to increase

由於ENVISAT很可能在今後150年內一直在環繞地球的軌道上運行，而且預計碰撞率會增加。

it could easily become a source of space junk some time in our future

它很可能在未來的某一天成為太空垃圾的源頭

The Kessler syndrome is not inevitable though and can be avoided if we try to avoid it

不過，凱斯勒綜合症並不是不可避免的，只要我們儘量避免，就可以避免這種情況的發生。

we need to think of space the same way we should think of our oceans and land

我們需要以看待海洋和陸地的方式來看待空間。

A valuable ressource that is in an entire need of protection

一種寶貴的資源，完全需要保護。

The only way to remove garbage from space is to go up and remove it ourselves

從太空中清除垃圾的唯一方法就是自己上去清除垃圾。

or wait for a very long time for it to go away naturally

或等待很長時間自然消失

Abandoning space is never an option

放棄空間絕不是一種選擇

NASA already concluded in 2005 that even if no further launches of objects into space were made, collisions

美國航天局已經在2005年得出結論，即使不再向太空發射物體，也會發生碰撞。

between already existing satellites would create fragments faster than atmospheric drag would remove fragments

已有的衛星之間產生碎片的速度比大氣阻力消除碎片的速度快。

The situation is an incredibly serious one with humanity's future literally on the line

情況非常嚴重，人類的未來岌岌可危。

We have to explore ways to improve this situation in the future, and we must carry on in the present and hope for the best

我們要探索未來改善這種狀況的方法，我們要立足現在，寄希望於未來。

If you want to one day work in space and help the humanity avoid the Kessler syndrom, you'll need a better

如果你想有一天在太空工作，幫助人類避免凱斯勒綜合症，你需要一個更好的。

understanding of how gravitational fields and orbits work, and there's no better place

瞭解引力場和軌道的工作原理，沒有比這更好的地方了。

to gain an understanding of scientific concepts than brilliant.org

來理解科學概念，比輝煌網。

As of their learning in their gravitational physics course, earth's gravitational field looks more like this

根據他們在引力物理課程中的學習，地球的引力場更像這樣。

and if you drop a bowling ball right here, it will be tavelling 1389 meters per second when it crashes into the surface

如果你把一個保齡球扔在這裡 當它撞上地面時，它將以每秒1389米的速度前進

at brilliant, you'll learn about complex topics in an easy to understand way

在輝煌，你將會以一種簡單易懂的方式學習複雜的主題。

like the Hohmann transfer with their straight forward explanation

就像Hohmann轉會時的直接解釋一樣

simple graphics and thought provocing puzzles which help you think like a scientist

簡單的圖形和發人深省的謎題，幫助你像科學家一樣思考。

by going to brilliant.org/reallifelore using the link in the description you can learn about anything you want to

通過訪問 brilliant.org/reallifelore，使用描述中的鏈接，你可以瞭解任何你想要的東西。

completely for free with a 3 day free trial

完全免費的3天免費試用

this free trial is exclusive only to the viewers of this video

此免費試用僅對本視頻的觀眾開放。

so go ahead and give brilliant a chance and learn something new credits : MAGICAL MOOO

所以，繼續給輝煌的機會，學習新的東西信用。神奇的MOOO