In real life, you could barely see it.

在生活中，你不太能看見它們。

It's just a little speck suspended in the atmosphere anywhere from a few days to several years.

它就是在空氣中到處懸浮數天至數年的小小粒子。

It could be dust from a desert.

它可以是來自沙漠的灰塵。

Or salt from ocean spray.

或者海霧中的鹽分。

It could have been blasted out of a volcano.

它也能可能來自火山噴發。

Or created during a forest fire.

或者森林大火產生的。

It might have flown out of a factory smokestack.

它可能是從工廠煙囪裡飄出來的。

Or a truck's tailpipe.

或從卡車的排氣管。

Depending on what it is—and where it is—an aerosol particle can do some impressive things.

依據它的特性及它出現的地方，一個氣溶膠體可以有很令人驚豔的表現。

Like cool the planet by reflecting sunlight back into space.

例如將陽光反射至外太空來冷卻星球。

Or by collecting water vapor to build a cloud.

或搜集水蒸氣造雲。

On the other hand, some aerosol particles trap sunlight and heat the air, thus preventing clouds from forming.

另一方面來說，有些氣溶膠體會吸附日照並加熱空氣因此避免雲的產生。

Other aerosols can host chemical reactions that damage the ozone layer.

其他氣溶膠可以主導傷害臭氧層的化學反應。

And down on Earth, they can even cause health problems, such as lung and heart disease.

而在地球上，他們可能會引起健康問題，例如肺部及心臟疾病。

That layer of hazy air pollution above big cities?

那層籠罩在大城市上空霧濛濛的空汙？

Yep, it contains aerosol particles.

沒錯，那個也含有氣溶膠。

Aerosols.

氣溶膠。

They're tiny.

它們很小。

They're powerful.

它們很強大。

NASA studies them with satellites and instruments on the International Space Station, and with specialized aircraft and ground-based devices.

NASA 用在國際太空站的衛星和儀器以及特殊的飛機及地面儀器來研究它們。

Because when it comes to understanding our environment, our climate, and how it's all changing, little particles make a big difference!

因為當我們了解我們的環境與氣候以及關於變遷的一切，小小的粒子可以造成大大的改變！