Below you will find our sun. Our star is 2 octillion tons of hot hydrogen gas emitting

往下面你就會找到我們的「太陽」，這顆恆星是團2x10²⁷噸的熱氫氣

400 septillion joules of energy every second. The hottest part of the sun is its 15 million°C

每秒散發出4x10²⁶焦耳的能量。太陽最高溫的部分是攝氏1500萬度的核心

core, where it's been fusing hydrogen into helium for the past 4.6 billions years. Despite

46億年來，這裡不斷把氫熔合轉換成氦

that, it's only considered a middle aged star!

儘管如此，太陽還只算處於中年期呢！

Now let's check out the closest planet to our sun, Mercury. Orbiting the sun in just

現在來看看最靠近太陽的行星「水星」，繞行太陽一圈只要88天

88 days, Mercury also has the most elliptical orbit of any planet. It spins very slowly,

水星的繞行軌道還是其他行星中最橢圓的，自轉速度非常緩慢

once every 2/3 of its orbital period. Despite its surface reaching a blistering 430°C, it still has

自轉一次時為軌道週期的三分之二。雖然水星表面可達熾熱的攝氏430度

water ice in permanently shadowed craters near its poles, where the temperatures stay below -170° C.

但在南北極附近，終年陰暗的坑洞中擁有冰，這裡的氣溫維持在攝氏負170度以下

The next planet in our solar system is Venus. It's the planet with the hottest surface

太陽系的下個行星是「金星」，有著最熱的表面溫度，攝氏460度

temperature; at 460°C it's hot enough to melt lead. Its air is almost entirely composed

足以把鉛融化。金星的大氣幾乎都由二氧化碳組成

of carbon dioxide, with a thick layer of sulfuric clouds. Its rotational axis is flipped upside-down,

和一層濃厚的硫酸雲。金星的自轉軸上下翻轉

which means that the planet spins backwards.

意味著金星的自轉方向是逆著轉的

The third and best understood planet is Earth. Our home planet has a dense metal core, a

第三顆行星，就是我們最熟知的「地球」。我們的母星有著高密度的金屬核心

thick viscous rock mantle, and a thin crust. It's unique in the solar system for having

黏稠而厚厚的岩石地函，還有薄薄的地殼。地球是太陽系中唯一一顆人類居住、

humans and permanent liquid water on its surface. Other planets may get the former soon.

液態水永存於表面的行星。也許不久後，人類能居住到其他行星上

At 3470 km in diameter, our Moon has the largest moon-to-planet size ratio. It's thought to have

月球直徑3470公里，以衛星與行星的相對大小比例來說，月球是最大的

formed when a small planet impacted Earth at a grazing angle billions of years ago.

月球被認為是幾十億年前，一顆小行星擦撞地球而形成

It's heavily cratered, and has huge flood plains on it called maria.

月球表面坑坑洞洞，還有大片泛濫的平原，稱作「月海」

Next up in our system is Mars. Its iconic red color comes from its rusty rocks and dust.

接著在太陽系裡的是「火星」，它指標性的紅色來自生鏽的岩石及塵埃

In the past Mars was once very wet, with oceans, a thick atmosphere, and a warmer climate.

火星曾經相當潮溼，存在海洋、厚大氣層還有較溫暖的氣候

But its lack of a magnetic field meant no protection from the solar wind, which eroded its atmosphere away.

但火星缺乏磁場，也就無法防護太陽風消蝕大氣層

Between Mars and Jupiter is a large asteroid belt.

火星跟木星之間有條巨大的小行星帶

It's a ring shaped region containing rubble leftover from the formation of the planets.

行星形成時的殘骸、碎片，組成了這個環狀區域

Past the asteroid belt we find our systems Jovian planets, starting with Jupiter.

穿過小行星帶，我們可以找到太陽系中的類木行星，第一顆為「木星」

A gas giant, it's the largest planet in our solar system. It has a dynamic atmosphere, including

木星是顆氣態巨行星，也是太陽系中最大的行星，擁有動態的大氣層

belts, zones, and a gigantic red spot created by a persistent hurricane. The Great Red Spot

大氣層有帶、區之分，還有持續的氣旋形成的巨大紅斑

is a persistent anticyclonic storm. The spot is large enough to contain three Earth-sized

大紅斑是個持久性反氣旋風暴，大小足以容納三個地球

planets. It's still unclear what exactly gives the spot its red color.

而大紅斑呈現紅色的原因還是不清楚

The next planet in our system is Saturn. It's a gas giant with a broad set of rings.

太陽系的下個行星是「土星」，也是氣態巨行星，有著一組寬闊的土星環

It has a hexagonal cloud pattern on its north pole. It's the least dense of all the planets,

土星北極有六邊形雲彩，其密度低於其他行星

even less dense than water! Made up of ice particles, Saturn's rings are 250,000 km across,

甚至比水還要低呢！土星環由冰的微粒組成，寬度為25萬公里

but only 10 meters thick! Gaps in the rings are created the gravitational tugging of the moons orbiting Saturn.

但厚度竟然只有10公尺！土星環的縫隙，來自土星許多衛星的引力拉扯

Uranus is an ice giant with a small rocky core and a thick mantle of ammonia, water, and methane.

「天王星」是顆冰巨行星，有小顆的岩石核心，和氨、水、甲烷組成的龐大地函

It also has thirteen distinct rings. Uranus has a huge tilt -- 98°, with respect to its orbit.

天王星也有13個清晰的環。從運行軌道來看，天王星有十分傾斜的角度─98度

A massive glancing collision long ago is one hypothesis to explain the extreme tilt.

解釋其異常傾斜的一種假設是：很久以前，天王星受到強大而傾斜的撞擊

Technically considered the last planet in our solar system, Neptune is an ice giant,

「海王星」也是冰巨行星，基本上算是太陽系最後一顆行星

with a similar composition to Uranus. It's the most dense of the outer planets and the

成分與天王星相似。海王星是帶外行星中，密度最大的

only planet found by mathematical prediction rather than by empirical observation.

海王星是唯一由數學預測而找到的行星，而不是靠經驗觀察

At the outer edges of our solar system we find the Kuiper Belt, filled with smaller rocky and icy bodies.

在太陽系的外緣，我們可以找到庫柏帶，是由較小的岩石及冰組成

Pluto is in this region. It was originally discovered in 1930 and categorized as a planet,

冥王星即在此區，1930年發現冥王星時，原本把它列為行星

but it was recategorized as a minor planet in 2006.

但在2006年重新歸類為微型行星

And there you go -- a crash course on our solar system. Even though we've explored a lot of it, there's still

就是這樣啦！太陽系構造的速成班。雖然我們探索了不少

a huge amount left to discover. And that's the beauty of science: there's always more to learn.

但還有好多好多有待我們去發掘。這正是科學的美妙──永不止息的學習

Thank you so much for watching! This video was created by the folks at Thought Café

非常謝謝你的收看！影片是由Thought Café製成

who have their own channel with awesome animated videos. Make sure to check them out and subscribe.

Thought Café頻道裡有許多精美的動畫短片。一定要去看看還有訂閱

Links below in the doobly-doo!

連結就在下方的資訊欄裡喔！