英语听力：自然百科 行星旅行：土星 Saturn—7

 And the icy grains on the Saturnian beaches are washed by passing traffic. When a moon comes by, it creates a wake just like a motor boat creates a wake that goes behind it. And I kind of imagine the ring particles doing an intricate cosmic dance around the planet, and I can almost picture like little ballet dancers that each with their own orbits and paths, and sometimes colliding and encountering, and sometimes not. 

 

 

 

Deeper secrets of this cosmic ballet are revealed, courtesy of a seasonal² trick of the light. Once every 15 earth years, as Saturn¹ makes its slow trip around the sun, summer swops hemispheres. In 2009, Cassini was in a perfect position to witness equinox on Saturn. 

 

 

 

The sun at exact equinox will be shining exactly adjoining to the rings, but a little bit before / a little bit after, the sun will be low to the rings, just like the sun is now low/ from London. And invertible³ protuberances either up or down below the rings will pass very long shadows, and we have in fact found that the rings aren’t completely flat, there are places where the ring particles in fact form these structures that soar a mile or 2 or 3, above the planet rings. The first time in 400 years, we now know that the rings are 3 dimensional. 

 

 

 

Enormous and enormously complicated, the rings also form a major part of Saturn’s amazing weather machine. Upon arrival you might be slightly disappointed that the cloudy face of Saturn looks a little plain. But the planet beneath the rings is wild at heart.

1 Saturn   

n.农神，土星

参考例句：

• Astronomers used to ask why only Saturn has rings.天文学家们过去一直感到奇怪，为什么只有土星有光环。
• These comparisons suggested that Saturn is made of lighter materials.这些比较告诉我们，土星由较轻的物质构成。

2 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

3 invertible   

adj.（可）倒转的，（可）颠倒的

参考例句：

• We shall prove that the sphere of any infinite-dimensional normed space is invertible. 我们将致力于证明任何无穷维赋范空间的球面皆为可逆。 来自互联网