60秒科学:Water Blankets Forming Planets

Water Blankets Forming Planets
A study in the journal Science finds much more molecular¹ water in regions where planets are forming around young stars. The mechanism² to keep the water from being destroyed by UV radiation appears to involve some of the water molecules³ shielding the rest. Cynthia Graber reports

In 2008 astronomers⁴ discovered surprising amounts of water molecules where planets were forming near young stars. But how, they wondered, could those molecules survive? They should have been destroyed by ultraviolet radiation. In theory, planetary dust could block out UV rays, but the dust was bound up in the creation of those young planets. So what's protecting the water? Now researchers at the University of Michigan believe they have the answer, which they published in the December 18th edition of the journal Science.

The regions where planets are being created are incredibly chemically productive, rapidly generating new compounds. According to the researchers, some water molecules surround the almost-planet dust and act as almost a sacrificial layer. The water molecules absorb the ultraviolet rays—and, though those molecules are destroyed, the embryonic⁵ planet is shielded. And the region is producing water faster than the protective layer is being destroyed.

The scientists say this action is similar to our ozone⁶ layer, which blankets us with protective shielding from UV radiation. They tested this idea in computer models and found that the results mirrored the observations. Seems that having water when a planet’s finished requires sacrificing some in the process.
 

1 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

2 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

3 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

4 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• 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。 来自《简明英汉词典》

5 embryonic   

adj.胚胎的

参考例句：

• It is still in an embryonic stage.它还处于萌芽阶段。
• The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

6 ozone   

n.臭氧，新鲜空气

参考例句：

• The ozone layer is a protective layer around the planet Earth.臭氧层是地球的保护层。
• The capacity of ozone can adjust according of requirement.臭氧的产量可根据需要或调节。