A sun umbrella in space

重慶 袁 泉

主題語境：科技發(fā)展 篇幅：347詞 建議用時：7分鐘

1Scientists have floated the idea of using a giant space“umbrella”as a solar shield (護罩) to protect the Earth from too much sunlight and help reduce global warming.

2István Szapudi, an astronomer at the University of Hawaii Institute for Astronomy,had the bright idea of tying the huge shield to a captured asteroid (小行星) so it would have a counterweight (平衡物).This would prevent it from falling back to the Earth because of the forces of gravity or blowing away in space.

3He said studies using this approach could start now to create a workable design that could reduce climate change within decades.“In Hawaii, many use umbrellas to block the sunlight as they walk about during the day. I was thinking, could we do the same for the Earth and thereby reduce the approaching disasters of climate change?”Mr Szapudi said on the University of Hawaii's website.

4In his paper, published in theProceedings of the National Academy of Sciences, Mr Szapudi explained that one of the simplest ways to lower the global temperature is to shade the Earth from just a small part of the Sun's light.

5This idea has been thought of before, but the large amount of weight needed to make a shield made previous suggestions too expensive to build.

6Mr Szapudi found that placing a tied counterbalance towards the Sun could reduce the weight to approximately 3.5 million tonnes—about 100 times lighter than other ideas.Using the asteroid would prevent having to launch most of the mass from Earth. With newer, lighter materials, the weight of the shield could be reduced even further and it would be faster and cheaper to build and launch than other shield designs.

7Today's largest rockets can only lift about 50 tonnes to low Earth orbit, so Mr Szapudi's suggestion would still be quite challenging. However, his approach makes the idea more probable, even with today's technology, while prior concepts were completely unachievable.

Reading Check

Detail1.What is the function of the giant shield?

A.To seek new asteroids.

B.To flow in space steadily.

C.To reduce global warming.

D.To improve the forces of gravity.

Detail2.What environmental problem could the giant shield help solve?

A.Climate change. B.Global pollution.

C.Lower temperature. D.Unbalanced rockets.

Detail3.What inspired Mr Szapudi's idea?

A.Scientists can capture asteroids in space.

B.People use umbrellas to block the sunlight.

C.Newer,lighter materials were invented recently.

D.Today's technology develops more quickly than ever.

Inference4.What has prevented this scientific suggestion from being tried before?

A.An asteroid. B.Public's doubts.

C.Heated debates. D.High costs.

Language Study

Ⅰ.Difficult sentence in the text

István Szapudi,an astronomer at the University of Hawaii Institute for Astronomy,had the bright idea of tying the huge shield to a captured asteroid so it would have a counterweight.夏威夷大學(xué)天文研究所的天文學(xué)家István Szapudi 有一個聰明的想法，那就是把巨大的護罩綁在被捕獲的小行星上，這樣它會有一個平衡物。

【點石成金】本句是一個并列句，so連接兩個并列分句。

Ⅱ.Fill in the blanks with the words and phrases in the box.

1.Please give us________notice if you need an evening meal.

2.For new reporters,this can seem like a________task.

3.Our English teacher is________in her forties.

4.A storm is coming!Tie things down before they________!

5.Experts have warned Africa's elephants could be extinct________.