The gas giant has the same basic ingredients as the sun and is surrounded by dozens of geologically diverse moons.

這個主要由氣體組成的巨大星球和太陽有著一樣的組成成分，且被數十個地質不同的衛星所圍繞。

Out of the 79 confirmed surrounding Jupiter, four ancient moons have astronomers really excited because they offer up some of the most distinctive geology in the solar system, including clues of deep, subsurface oceans that could be home to life.

在七十九個確認環繞著木星的衛星中，有四個古老的衛星讓天文學家們非常興奮，因為它們提供了太陽系中數一數二獨特的地質，包含有關可能孕育生命的深層的、在表層底下的海洋的線索。

The Galilean moons are named after Galileo Galilei, who first observed them in 1610.

伽利略衛星得名自在 1610 年時，第一次觀測到它們的伽利略 • 伽利萊。

Io, Jupiter's closest Galilean moon, is unusual because its composition is closer in comparison to the terrestrial planets than the icy bodies that surround it.

埃歐，最靠近木星的衛星並不尋常，因為它的組成物比起環繞其四周的冰凍的星體，更像是類地行星。

Io is also the most volcanically active body known in the solar system with over 400 active volcanoes.

埃歐幾乎是太陽系中火山活動最頻繁的星體，它有超過四百個活躍的火山。

This is due to the internal heating produced by the pulling and stretching effect of Jupiter's gravity and smaller neighboring moons on Io as it orbits Jupiter.

這是由木星引力的牽引效應及埃歐鄰近的小衛星在埃歐環繞木星運行時，促成其內部熱能所造成。

That same tug-of-war heating effect is the reason why some astronomers believe that Jupiter's second Galilean moon is home to a deep subsurface ocean up to twice the volume of Earth's oceans.

那相同的拔河般的熱能效應也是一些天文學家認為木星的第二顆伽利略衛星，有一個相當於地球海洋兩倍大的深層海洋的原因。

Unlike Io, Europa has an icy surface, but below it, astronomers think there may be a salty ocean that could harbor life-bearing chemistry, including organic molecules.

不像埃歐，歐羅巴的表層覆蓋著冰，但天文學家認為其下可能有一個富含鹽的海，這片海蘊含了可供生命孕育的化學物質，包含有機的分子。

When Europa swings by Jupiter on an elliptical orbit, gravitational tidal forces stretch and flex the sides of the moon, creating internal friction that essentially heats the moon from the inside out.

當歐羅巴以橢圓型的軌跡在木星周圍運行時，潮汐力會壓縮或拉伸衛星的邊緣，製造出內部的摩擦力，讓衛星從內部加熱。

Using its Europa Clipper spacecraft in the 2020s, NASA plans to get a closer look at the moon in order to confirm the existence of a potential ocean.

預計在 2020 以後使用歐羅巴快艇太空船， NASA 計畫更進一步地觀察這顆衛星，以確認潛在的海洋是否存在。

Europa's neighbor, Ganymede, is also believed to have an ocean hidden under its thick icy shell.

歐羅巴的鄰居，蓋尼米德，也被認定在其深厚的冰表層下，藏著一片汪洋。

The moon's magnetic field may be affected by an electrically conducting layer from within, which hints at the existence of a liquid saltwater ocean.

這顆衛星的磁場可能受其內部的導電層影響，這暗示著一個蘊含鹽分的液態海洋的存在。

But Ganymede's distance from Jupiter means there's a weaker tidal force at play, so it's less likely that liquid water is present.

但蓋尼米德和木星的距離意味著潮汐力的作用較弱，所以有液態水存在的可能性較低。

The moon is the only one in the solar system known to have a magnetosphere, protecting its surface from harmful radiation and solar wind.

這顆衛星是在太陽系中唯一有磁氣圈的，這保護它的表層免於有害的輻射和太陽風侵襲。

As Jupiter's largest moon, Ganymede would be considered a planet if it were orbiting the Sun.

作為木星最大的衛星，如果蓋尼米德繞著太陽運行，它會被認定成一顆行星。

Out of all four Galilean moons, Callisto is the farthest from Jupiter.

在所有四顆伽利略衛星中，卡利斯多是距離木星最遠的。

The moon is purported to be one of the most heavily cratered objects in the solar system.

這顆衛星據說是太陽系中，有最多坑洞的星體的其中一個。

With some impact basins expanding to about 2,600 kilometers across, these craters could teach us a lot about the formation of our early solar system, as astronomers believe its surface hasn't changed in over four billion years.

有些撞擊坑直徑達兩千六百公里，這些隕石坑教導我們許多關於我們早期太陽系的形成的事，因為天文學家相信其表層四十億年來沒有改變過。

Unmanned spacecraft have been conducting flybys of the Galilean moons for decades and findings from these missions suggest an even greater presence of water.

無人太空船已經執行靠近伽利略衛星的探測飛行數十年，從這些任務得到的發現更顯示液態水的存在。

Along with NASA's Europa Clipper, the European Space Agency's JUpiter ICy moons Explorer, aka JUICE will gain a deeper understanding of the moons' mysterious properties.

和 NASA 的歐羅巴軌道器一起，歐洲太空總署的木星冰月探測器，又稱為 JUICE，將會取得有關衛星的神秘組成更深入的資訊。

But getting to these moons will be no small feat since the craft will need to slingshot around the Sun and then travel about 800 million kilometers before being caught by Jupiter's massive gravitational pull.

但要到達這些衛星一點都不容易，因為飛行器必須被投射出去到太陽周圍，然後在被木星巨大的引力拉走前，飛行八億公里。

If the spacecraft can survive this arduous journey and manage to generate enough energy to travel between the moons, astronomers will gain an unparalleled glimpse into what lies beneath their surfaces, which could even result in the discovery of the first forms of life beyond Earth.

如果太空船可以撐過這艱鉅的旅程，並試圖產生足夠的能量來飛越這些衛星，天文學家就能得到空前未有的，有關這些衛星表層下的資訊，這些資訊甚至可能揭露超越地球的最早的生命起源。

Spacecrafts takes you through the depths of the cosmos, explaining bizarre astronomical phenomena and crazy plans for future exploration.

太空船帶你深入宇宙，解釋了奇異的天文現象和未來探測的瘋狂計畫。

In this episode, we explain how an advanced civilization could harness the total energy of a star.

在這集節目中，我們解釋了一個先進的文明如何駕馭一顆星體的總能量。

Thanks for watching Seeker!

謝謝觀賞 Seeker！

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別忘了訂閱。