英语听力：探索发现 科学新发现：我们的大气层-7
时间：2019-01-23 作者：英语课 分类：探索与发现2014年
英语课
To discover why these twin planets followed separate paths and to explore what gave us our precious atmosphere, we have to travel back, back four and a half billion years to the birth of the solar system itself.
The birth of the solar system created Earth’s earliest atmosphere. Huge quantities of materials orbiting the Sun fused together into proto-planets. Jupiter and Saturn 1 formed into gassy spheres. But on Earth, most of the material condensed into a molten core. The remaining gases bubbled forth 2 from the liquid rock, forming the first atmosphere.
Our planet’s gravity stopped these gases from drifting off into space. But Earth now had to face the ravages 3 of the solar wind, a stream of charged particles thrown out by the Sun. This same wind had a catastrophic effect on Mars. It has stripped the air from the planet’s surface, blasting it deep into space. The Red Planet’s atmosphere is now only a hundredth as thick as Earth’s.
n.农神，土星
- 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。
adv.向前；向外，往外
- The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
- He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。