降落的美国卫星将在周五撞击地球

短语讲解：

1. So, I don't think anybody needs to be unduly concerned about it.

concern about使(自己)关心…
例句：There is no need for you to concern yourself about where I was last night.
你没必要关心我昨晚在哪儿。

2. Most of UARS is expected to burn up in the atmosphere.

burn up烧起来,烧掉,发怒
例句：Put some wood on the fire and make it burn up.
添些木柴把火烧旺。

3. Even though officials at NASA and the Department of Defense cannot yet provide a precise landing footprint, Matney says the science of figuring out what will land is exacting.

figure out计算出; 解决
例句：I have figured out how much during the week I spent.
我算出了这个星期花了多少钱。

4. And we actually have computer programs that model the dynamics as it begins to heat up and break up and look at the temperatures those pieces reach and whether they reach the melting point of the metal.

heat up变热
例句：The iron heats up under the sun.
铁在阳光照射下温度升高。
break up (使)破碎, 分解
例句：The specs fell on the cement floor and broke up.
眼镜掉在水泥地上破掉了。

5. For instance, he says that because of aluminum's relatively low melting temperature, aluminum objects usually disintegrate before they reach the surface of the Earth.

for instance例如, 比如
例句：You cannot rely on her; for instance, she arrived an hour late for an important meeting yesterday.
她这人靠不住, 例如昨天一个重要会议, 她迟到了一个小时。

6. NASA expects 26 "potentially hazardous" pieces of UARS to reach the ground, most of them made of titanium, stainless steel or beryllium, which have high melting points.

make of用…做成
例句：The table is made of wood.
桌子是木制的。

7. UARS debris is expected to range in mass from 0.6 to 158 kilograms.

in mass全体, 整个地
例句：We will adopt their suggestions in mass.
我们将全盘采纳他们的建议。

8. One aim is to prevent pieces of space junk from colliding and breaking into smaller pieces as well as to keep active satellites and spacecraft safe.

prevent from阻止, 防止
例句：His prompt action prevented the fire from spreading.
他的果断行动制止了火势的蔓延。
break into把…分成
例句：Mary broke the chocolate into pieces, one for each person.
玛丽将巧克力分成小块, 每人一块。

9. NASA's Mark Matney says the space agency took steps in 2005 to decommission the Upper Atmosphere Research Satellite.

take steps 采取措施
例句：They took steps to prevent the spread of influenza.
他们采取措施阻止流感的传播。

10. Even though it is commonly referred to as "space junk," the debris still belongs to the country that owns the craft, in this case, the United States.

belong to属于
例句：Victory belongs to the most persevering.
胜利属于最有毅力的人。