VOA慢速英语--地球新的“微型卫星”可能只是美国宇航局旧任务中的太空垃圾

Asteroid¹ or Space Junk? NASA Thinks Mystery Object Could Be Old Rocket

A space object recently discovered as a possible asteroid may actually be an old rocket from a failed moon-landing attempt in the 1960s.

Astronomers² observed the object last month through a telescope based in Hawaii. The scientists documented the object as an asteroid that was on its way toward Earth. Searching for such objects is common among astronomers as part of international efforts aimed at protecting Earth against asteroid hits.

The object was given the name 2020 SO. It was added to the International Astronomical³ Union's Minor⁴ Planet Center's list of asteroids⁵ and comets found in our solar system. Currently, the list is just a little under 1 million.

But the American space agency NASA's leading asteroid expert, Paul Chodas, says he believes the newly discovered object is not an asteroid at all. Instead, he believes the object is a piece of space junk.

Chodas has suggested that the object is likely the old booster rocket that successfully pushed NASA's Surveyor 2 lander to the moon in 1966.

"I'm pretty jazzed about this," Chodas told The Associated Press. "It's been a hobby of mine to find one of these and draw such a link."

Chodas has been studying asteroids for many years. He is currently director of the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory in Pasadena, California.

Surveyor 2 was a robotic spacecraft that crashed into the moon after one of its engines failed to start during the trip. The rocket, named Centaur⁶, kept flying past the moon as planned and became space junk.

The object being observed is estimated to be about 8 meters long based on its brightness. That is about the size of the old Centaur rocket.

Chodas said the first thing that caught his attention was the object's near-circular orbit around the sun, which is very similar to Earth's. Such behavior is unusual for an asteroid. Chodas said the movement represented "flag number one" that the object is not an asteroid.

The mysterious object is also in the same plane as Earth, not positioned above or below. That was the second red flag for Chodas, since asteroids usually travel at uneven⁷ angles. Lastly, Chodas said the object is coming toward Earth at about 2,400 kilometers an hour, which is considered very slow for an asteroid.

As the object gets closer to Earth, astronomers should be able to better follow its orbit and observe how much it is pushed around by radiation and heat effects of the sun. If it is an old empty rocket, it will move differently than a heavy space rock that is not as affected⁸ by outside forces.

The movements are how astronomers usually tell the difference between asteroids and space junk such as used rocket parts.

Chodas said there are likely numerous fake asteroids out there. But if the movements of the objects cannot be effectively observed or measured, it is difficult to confirm their exact identities.

Sometimes, however, it can be the other way around. In 1991, Chodas and others identified a mystery object as an asteroid rather than space junk, even though its orbit around the sun was very similar to Earth's.

In 2002, Chodas discovered what he believes was the leftover⁹ Saturn¹⁰ V booster rocket from 1969′s Apollo 12, the second moon landing by NASA astronauts. He admits the evidence was circumstantial, given the object's one-year orbit around Earth. The object was never documented as an asteroid, and left Earth's orbit in 2003.

But Chodas says the latest object's path is more direct and much more stable, which strengthens his theory. "I could be wrong on this. I don't want to appear overly confident," he said. "But it's the first time, in my view, that all the pieces fit together with an actual known launch."

Carrie Nugent is an asteroid hunter at Olin College of Engineering in Needham, Massachusetts. She said Chodas' theory is "a good one" based on strong evidence. Nugent is the writer of the 2017 book "Asteroid Hunters."

"Some more data would be useful so we can know for sure," she told the AP in an email. "Asteroid hunters from around the world will continue to watch this object to get that data. I'm excited to see how this develops," she added.

Words in This Story

asteroid – n. a rocky object that goes around the sun like a planet

jazzed - adj. excited and happy

junk - n. things that are considered to be no longer useful or valuable

hobby – n. something done for pleasure, not for a job

angle – n. a space between two lines or surfaces that meet at one point

fake – adj. not real

booster – n. engine on a spacecraft that gives extra power for the first part of a flight

circumstantial – adj. containing information about something that makes you think it is true but not having enough evidence to completely prove it

stable – adj. firmly fixed¹¹ and not likely to move or change

confident – adj. feeling or believing that one has the ability to succeed in something

1 asteroid   

n.小行星；海盘车(动物)

参考例句：

• Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
• It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

2 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》

3 astronomical   

adj.天文学的，（数字）极大的

参考例句：

• He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
• Houses in the village are selling for astronomical prices.乡村的房价正在飙升。

4 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

5 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

6 centaur   

n.人首马身的怪物

参考例句：

• His face reminded me somehow of a centaur.他的脸使我想起半人半马的怪物。
• No wonder he had soon been hustled away to centaur school.也难怪父母匆匆忙忙就把他送到了半人马学校。

7 uneven   

adj.不平坦的，不规则的，不均匀的

参考例句：

• The sidewalk is very uneven—be careful where you walk.这人行道凹凸不平—走路时请小心。
• The country was noted for its uneven distribution of land resources.这个国家以土地资源分布不均匀出名。

8 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

9 leftover   

n.剩货，残留物，剩饭；adj.残余的

参考例句：

• These narrow roads are a leftover from the days of horse-drawn carriages.这些小道是从马车时代沿用下来的。
• Wonder if that bakery lets us take leftover home.不知道那家糕饼店会不会让我们把卖剩的带回家。

10 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。

11 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。