VOA慢速英语:California Study Finds Moon is 4.51 Billion Years Old

For almost as long as people have walked on Earth, they have looked up at the moon and wondered:How did the moon get there? How long has it been there?
几乎从地球上开始有人行走以来，他们就抬头仰望月亮并疑惑：月亮是如何到达那儿的？它已经在那儿多长时间了？
Scientists have studied these questions.And now, a group of researchers from California have an answer.Based on their studies, they think the moon is 4.51 billion years old.
科学家们已经研究了这些问题。目前，来自加利福尼亚的一组研究人员已经得出了结论。根据他们的研究，他们认为月球形成已经有45.1亿年了。
For years, researchers have been studying the many rocks American astronauts brought back from the moon between 1969 and 1972.The early rock studies led many scientists to think the moon was formed long ago -- about 4.3 billion years ago.
多年来，研究者们研究了很多美国宇航员们于1969年到1972年间从月球带回来的岩石。早期的岩石研究使很多科学家认为月球在很久之前，大约43亿年前就已经形成了。
Scientists believe the moon was created when a huge rocky object about the size of Mars struck a very young Earth.Then some of the pieces from that violent crash came together in space to form the moon.
科学家们认为，一块跟火星差不多大的巨大岩石物体撞击了非常年轻的地球，从而产生了月球。剧烈撞击之后的一些碎片在宇宙中聚集到一起，从而形成了月球。
But that estimated age, 4.3 billion years, created a problem for scientists. That is because it does not leave much time for life to get started and develop on planet Earth.
但是这个估计的时间，43亿年，给科学家们带来了一个问题。因为，它并没有留下多少时间以供生命在地球上产生并形成。
Melanie Barboni is a researcher in the Department of Earth, Planetary and Space Sciences at the University of California, Los Angeles (UCLA).
梅兰妮·巴宝妮是洛杉矶加利福尼亚大学（UCLA）的地球、行星和空间科学部门的一名研究员。
“Here at UCLA, there has been this study that has found that life could have appeared as early as 4.1 billion years old. So now if you believe this giant impact occurred at 4.3, it doesn’t leave you a long time between the impact and basically the Earth being half destroyed and then the Earth acquiring all the condition you need for life.”
“在UCLA，有一项研究发现，生命可能早在41亿年前就产生了。因此如果你认为这个大碰撞发生于43亿年前，那么大碰撞和地球一半生物被毁灭之间就没有多少时间了，更别说这之后，地球又形成了生命所需的一切条件。”
Barboni and other researchers at UCLA wanted a better, more exact estimate of when the moon was formed.They found their answer by studying a moon rock brought back to Earth in 1971.Barboni says they looked closely for signs of a mineral called zircon.
巴宝妮和UCLA的其他研究员们想要对月球的形成时间做出一个更好的、更准确的估计。他们在研究一块1971年从月球带回地球的岩石时，找到了答案。巴宝妮说他们密切观察了锆石的迹象，这是一种矿物质。
“And we found out that the moon is actually older. The moon didn’t form at 4.3 billion years old, but it formed at minimum and that is a minimum age - it could even be slightly older, it formed at minimum 4.51 billion years old...”
“我们发现其实月球的年纪更大一些。月球并不是在43亿年前形成的，它至少形成于，这只是一个最近的时间，它可能更老一些，形成于45.1亿年前。”
She says saving those extra years solves the problem of life on Earth. And this solution gives scientists a better understanding of how life formed here and how it might form on other planets.
她说要考虑到多出来的这些年解决了地球上的生命问题。这个解释也能让科学家们更好地理解生命是怎样在这形成的，以及怎样才能使其在其他星球上形成。
“... you have much more time to cool down your Earth to like start, you know, having your plate tectonics things again, generate the atmosphere, generate the water and then finally having all the condition met for life.”
“有了更多的时间使地球平静下来并开始，你知道的，再一次进行板块构造，形成大气，产生水，最终拥有生命所需的所有条件。”
The new information means the moon was orbiting Earth just 60 million years after the birth of our solar system.
新信息意味着太阳系形成仅6000万年之后，月球就开始围绕地球转动了。
Noah Petro works as a researcher for NASA, the American space agency.He studies the moon at NASA’s Goddard Space Flight Center in Maryland.
诺亚·佩特罗是美国宇航局（简称NASA）的一位研究员。他在马里兰州NASA的戈达德宇宙飞行中心研究月球。
Petro is a geologist: someone with an expertise in rocks. He points out that the UCLA researchers were using a single rock to estimate the age of the moon’s surface.
佩特罗是一名地质学家，即专门研究岩石的人。他指出UCLA的研究员们使用一块单一的岩石来推测月球表面的形成时间。
He believes that the moon “is in the range of 4.5 billion years old.”
他认为月球“的形成时间在45亿年的范围之内。”
Petro adds that “understanding the age of the moon is very important to understanding the solar system.”Knowing when the moon was formed can tell scientists about when other events happened.
佩特罗补充道“了解月球的形成时间对于了解太阳系来说非常重要。”知道月球的形成时间可以告诉科学家们其他一些事件发生的时间。
Lunar rocks have been studied on Earth since American astronauts first landed on the moon. They brought back more than 20 kilograms of the rocks in July 1969.The last American astronauts on the moon brought back more than 100 kilograms of rocks in 1972.There are still rocks that have yet to be studied almost 45 years later.
地球上对于月球岩石的研究，是从美国宇航员首次登上月球之后开始的。1969年7月，他们带回了超过20千克的岩石。1972年，美国最后一批登上月球的宇航员们带回了超过100千克的岩石。还有足够之后研究约45年的岩石。
“Lunar samples are the gift that keeps on giving,” Petro says. “We will be studying them 45 years from now and 45 years after that.”
“月球样本就是礼物，它们不断给予新知识，”佩特罗说。“从现在起我们将会研究45年，然后再研究45年。”
But Petro says, “as much as we use rocks, it isn’t set in stone what happened.”
但是佩特罗说：“我们使用了这么多的岩石，得出的结果却不是一成不变的。”
That is because technology is always changing and new methods become available, providing new information from the rocks. Also, answers can be different, depending on what kinds of assumptions scientists make and how the information is processed.
这是因为科技在不断发展，新的方法也变得可用，从而发现岩石中的新信息。另外，答案可能会不同，取决于科学家们做出了怎样的假设，又是如何处理这些信息的。
“The rocks contain truth in them, it is up to us to understand what they are telling us,” Petro explains.
“这些岩石中包含了真相，但是如何理解它们告诉我们的内容，则取决于我们自己，”佩特罗解释道。
Scientists agree that a huge object they named Theia crashed into the young Earth to create the moon. But Petro says some evidence “does not really fit the model” of an impact — like the fact there is water inside the moon. Water should not be there if the moon resulted from a huge object striking Earth.
一个被称为忒伊亚的巨型物体撞击了年轻的地球，从而形成了月球，科学家们认同这种说法。但是佩特罗说一些证据“不适用于撞击这种说法”，例如，事实上月球内部有水存在。如果月球是由于巨型物体撞击地球而形成的，那么水不应该存在。
This means the model needs to be “revisited,” Petro says.And that means scientists will continue to study the moon to find more answers.
这意味着这种说法需要“重新探究”，佩特罗说。也就意味着科学家们要继续研究月球以寻找更多的答案。
Currently, Petro is working with NASA’s Lunar Reconnaissance Orbiter project.Since June 2009, the space agency has been gathering information from the orbiter, which is circling the moon.Scientists have seen new impact areas that show where meteorites or other objects have struck the surface.
目前，佩特罗在NASA的月球勘测轨道飞行器项目工作。从2009年6月起，宇航局就一直利用这个围绕月球旋转的轨道飞行器收集信息。科学家们发现了新的撞击区域，表明陨石或其他物体撞击过月球表面。
Scientists have also learned that the far side of the moon — the side facing away from Earth — does appear to be different than the side we see from here. Petro says there is less volcanic activity on the far side and there is a large crater, or impact area, there.He hopes NASA will be able to send a probe to the crater to find out why that side is so different.
科学家们还认识到月球的另一面，背对着地球的那一面，好像和我们看到的这一面不同。佩特罗说在月球的那一面，火山活动没有那么活跃，并且那面有一个很大的火山口，或称为撞击区域。他希望NASA能够往那个火山口处发送一个探测器，以弄清楚为什么那一面如此不同。
Sending a probe to the far side of the moon will require a special satellite because the spacecraft will not have a straight line to communicate with Earth.
往月球的另一面发送探测器需要一个特殊的人造卫星，因为宇宙飞船将不能与地球进行直线交流。
China also wants to explore the far side of the moon.In December 2016, the Chinese space agency announced its five-year plan for space exploration.It includes sending a probe to the far side of the moon.One expert says there are suggestions that China may also send humans there eventually.
中国也想探测月球的另一端。2016年12月，中国宇航局宣布了太空探索的五年计划。其中包括向月球的另一端发射一个探测器。一名专家表示，这也暗示了中国可能最终也会送人去月球的另一端。
So humans are far from finished looking up at that bright round object in the sky, and wondering, what is up there?
因此人类还远不能停止仰望天空中的那个又亮又圆的物体，疑惑着那到底是什么。
I’m Anne Ball.
我是安妮·鲍尔。