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  • Somewhere between the orbits of Mars and Jupiter,

    在火星和木星運行軌道之間的某處,

  • about 500 million kilometers away from Earth,

    距離地球約五億公里,

  • floats a metallic orb the size of Massachusetts.

    懸浮著一個如麻州大小的金屬球

  • That's no moon...it's 16 Psyche,

    那不是月球...它是「靈神星」

  • one of the most massive asteroids in the solar system.

    太陽系中最大的小行星之一

  • And it is the asteroid our droids are looking for.

    也正是我們探索機器人在尋找的

  • We humans have managed to send robotic spacecraft

    人類已經送出太空船

  • to all sorts of environments in space

    至宇宙中各種環境的星球

  • the gas clouds of Saturn and Jupiter,

    被氣雲圍繞的土星和木星

  • the icy wastes of Europa,

    包覆在冰層之下的木衛二- 歐羅芭

  • and the rocky dunes of Mars.

    及火星上的岩狀沙丘

  • But Psyche's surface isn't just hard rock

    但靈神星的表面不只是岩石

  • it's heavy metal.

    還有重金屬

  • The asteroid mostly consists of nickel and iron,

    這個小行星主要由鎳和鐵構成

  • by far the largest known body with such a composition.

    是至今已知此結構中最大的小行星

  • But we don't yet know what it looks like;

    但我們仍不知其外觀特徵

  • our best current radar images show a pixelated smudge.

    目前最好的雷達圖像只揭示出模糊的像素

  • That'll change in 2026,

    到 2026 年, 當美國太空總署探索計畫送出的

  • when an unmanned spacecraft sent as part of NASA's Discovery Program

    無人機到達時

  • is scheduled to arrive.

    這將改變

  • So why is NASA so interested in Psyche?

    美國太空總署為何對靈神星如此感興趣?

  • Are we going to mine all that metal, or build a giant space magnet?

    難道我們要開採上面的金屬礦,或是建造巨大的太空磁鐵?

  • Actually, the real reason is right under our feet.

    事實上,正確答案就在我們腳下

  • The core of the Earth is thought to consist of a solid nickel-iron center

    地球核心被認為由固體的鎳鐵組成,

  • with a molten outer layer.

    包覆在融化的液態外層下

  • But we're prevented from studying it up close by 2,800 kilometers of solid rock.

    但我們被 2,800 公里的岩層阻隔無法研究

  • The deepest we've been able to drill is 12 kilometers.

    目前人類地表探鑽的最深深度是 12 公里

  • Even if we could go further,

    即使我們能夠繼續深入

  • the pressure at the core is three million times higher than at the surface,

    地心的壓力是地表的三百萬倍

  • with a temperature of 5,000 degrees Celsius.

    攝氏 5,000 度

  • Simply put, a journey to the center of the Earth is out of the question for now.

    簡單來說,地星探險以目前來說是不可能的

  • So scientists have had to resort to indirect ways of studying the core,

    所以科學家必須採取迂迴的方式來研究地心

  • like measuring earthquake waves that pass through it,

    如測量穿透地心的地震波

  • or studying minerals thought to have formed there.

    或研究被認為是在其處形成的礦物質

  • But what if the best way to study Earth's inner space

    但若是研究地心最好的方式

  • is by visiting outer space?

    是探索外太空呢?

  • After all, we have a pretty good idea of how our planets formed.

    畢竟,我們已有一個地球是如何形成的概念

  • Dust and gas orbiting our young Sun cooled and collided

    環繞著我們年輕太陽的塵埃和氣體冷卻並相互撞擊

  • to form a few thousand miniature bodies we call planetesimals.

    形成幾千個微型星,我們稱之為星子

  • As these continued to orbit, some combined to grow larger,

    當這些星子持續依軌道運行,部分結合成了較大的星子

  • eventually forming our planets.

    最終形成了我們的行星

  • Others experienced impacts that broke them apart into smaller chunks

    另外的星子經歷撞擊分裂成更小的塊狀

  • the asteroids we see today in the belt between Mars and Jupiter.

    即我們今天在火星和木星之間的地帶看到的小行星

  • What makes Psyche so special

    靈神星何以突出?

  • is that it appears to have been a planetesimal

    原因是它正在歷經由星子

  • well on its way to becoming a planet,

    發展成行星的歷程

  • with a rocky exterior surrounding a metal core.

    且有岩層地表和金屬地心.

  • But its progress was cut short by a series of hit-and-run collisions

    但這歷程被一連串

  • with other planetesimals

    已遭受撞擊失去地殼只剩下核心的其他星子

  • that knocked off the rocky crust until only the core remained.

    之互相碰撞和分裂所縮短

  • Experiencing that many destructive collisions

    在經歷多次毀滅性的撞擊

  • with no additive ones in between is statistically very unlikely,

    卻沒有成長在統計學上是極不可能的

  • making Psyche an amazingly rare opportunity

    使靈神星成為可研究外露金屬地核

  • to study an exposed metallic core.

    的極特殊的機會

  • To do that, NASA's robotic orbiter will be equipped

    為了這項研究,美國太空總署的偵查軌道太空船會裝備

  • with an array of advanced instruments.

    大量的先進儀器

  • A spectrometer will analyze the gamma rays and neutrons

    光譜儀將會分析當靈神星受到宇宙射線侵襲的

  • produced when Psyche is struck by cosmic rays.

    伽馬射線和中子

  • Each element in the periodic table

    元素週期表中的每個元素

  • releases gamma rays of specific wavelengths,

    會釋放出特定波長的伽馬射線

  • so these measurements will tell us what elements are found on the surface.

    透過這些分析,我們會知道靈神星表面有什麼元素

  • A magnetometer will measure Psyche's magnetic field,

    磁力計將會測量靈神星的磁場

  • allowing us to learn more

    讓我們了解更多

  • about how Earth's magnetic field is generated at its core.

    地球地心產生的磁場

  • And of course, an imager will give us a closer look at the surface

    當然,成像儀會讓我們看到先前所未知

  • than ever before.

    的表面清晰圖像

  • Visiting a whole new kind of world is exciting enough on its own.

    探索一個全新的世界本身就是非常令人興奮的

  • But the mission to Psyche gives us a unique chance

    但探索靈神星的任務給予我們一個獨一無二在遙遠行星

  • to discover our own planet's innermost secrets in an orbit far, far away.

    發現我們自己的星球最深層的秘密機會

Somewhere between the orbits of Mars and Jupiter,

在火星和木星運行軌道之間的某處,

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B2 中高級 中文 美國腔 TED-Ed 行星 探索 撞擊 木星 太空

【TED-Ed】為何美國 NASA 要派太空船去探索鋼鐵星球? (Why is NASA sending a spacecraft to a metal world? - Linda T. Elkins-Tanton)

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    Samuel 發佈於 2018 年 03 月 19 日
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