社交英语口语视频(中级) 65 A Piece of the Sun

　　The sun and Jupiter have a lot in common.

　　The sun is made almost entirely of hydrogen and helium.

　　There's a sprinkling of the other elements,...

　　...but mostly hydrogen and helium.

　　But Jupiter is made of almost exactly the same stuff as the sun.

　　And yet Jupiter has a higher concentration of these heavier elements in it.

　　These elements are heavier.

　　They're more massive than hydrogen or helium.

　　So, you might have expected them to fall into the center of the solar system,...

　　...but no, they are stuck way out here at Jupiter.

　　Now, these elements are significant,...

　　...because these are the elements that make up the earth and you and me.

　　And you know why they're out here in Jupiter?

　　Nobody knows why, that's why we're sending the Juno mission out there.