VOA标准英语2014--欧洲航天局探测器登录彗星
时间：2019-01-14 作者：英语课 分类：VOA标准英语2014年(七月)
ESA Spacecraft to Land on a Comet 欧洲航天局探测器登录彗星
After a long flight through deep space, a European Space Agency probe is finally approaching its target - a comet millions of kilometers away from earth. Scientists say the mission may lead to some startling discoveries about the origins of the water on earth.
Ten years ago, a European Space Agency rocket took off with a spacecraft called Rosetta, on a mission to perform the most detailed 1 study of a comet.
While asteroids 2 are large rocks, almost like small planets, comets are mostly made of ice, says Ralph Cordey, the business manager for Airbus Defense 3 and Space, which built the Rosetta spacecraft.
“We know today that our Earth has a great deal of water on it, we don't know exactly where it came from and it's likely that comets had a lot to do with that process," said Cordey.
It took more than 10 years for Rosetta to make three swings around Earth and one around Mars - gathering 4 enough speed to reach the comet named 67P / Churyumov-Gerasimenko, 400,000 kilometers from Earth.
For the last two-and-half years many of its onboard systems were in the sleep mode to save energy, says Airbus engineer Simon Barraclough.
“So when we're close to the Sun, a lot of things are on. When we're further from the Sun, a lot of things are off," said Barraclough.
A 'wake-up call' in January brought cheers in the mission headquarters in Darmstadt, Germany, as a signal from Rosetta indicated that its computer was wide awake again.
The spacecraft will soon start orbiting the comet at a distance of about 10 kilometers, taking measurements and mapping its surface.
In November, it is scheduled to release a smaller probe called Philae, which will land on the comet.
Cordey says both Rosetta and Philae will measure the comet’s gas and dust and send pictures of its surface.
“It will also have a very nice radar 5 system onboard it which will communicate with the orbiting spacecraft - the mothercraft - and use the radar signals to probe the heart of the comet's nucleus 6. So it's not just looking at the surface or the environment around it, it's actually going to be probing what's underneath 7 the surface," he said.
The probes will travel with the comet for a full year.
Rosetta will continue measuring how the comet changes as it approaches the sun and starts to warm up, while Philae will analyze 8 samples of the its surface and subsurface.
- He had made a detailed study of the terrain.他对地形作了缜密的研究。
- A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
- 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。
- The accused has the right to defense.被告人有权获得辩护。
- The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。
- He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
- He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。
- They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
- Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。
- These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
- These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。
- Working underneath the car is always a messy job.在汽车底下工作是件脏活。
- She wore a coat with a dress underneath.她穿着一件大衣，里面套着一条连衣裙。