CHRISTOPHER CRUISE: This is SCIENCE IN THE NEWS, in VOA Special English. I'm Christopher Cruise.
您现在正在收听的是“VOA慢速英语”之“科学报道”。 我是Christopher Cruise。
BOB DOUGHTY: And I'm Bob Doughty. Today, we tell about evidence of liquid water on the planet Mars. We also consider a theory that the Earth once had a small second moon. And we celebrate summertime with a report about creatures known to light up the night sky.
我是Bob Doughty。 今天我们会聊到是什么让大家觉得火星上会存在着液态水。 节目同时也会提到一个理论，那就是在过去可能还有另外一个月亮在围绕地球旋转。 然后我们会在节目的最后送上一份关于萤火虫的报道来给这个夏日增加点乐趣。
CHRISTOPHER CRUISE: An American spacecraft orbiting Mars shows it is possible that the planet could someday support human life. The Mars Reconnaissance Orbiter has found the best evidence yet that liquid water flows on Mars during the planet's warm season.
据美国一艘针对火星研究的宇宙飞船的观察，将来人类也许可以在火星上生存。 火星勘测轨道器已经得到了有力证据证明火星在其暖季确实存在过液态水。
Charles Bolden heads the National Aeronautics and Space Administration. He says NASA's Mars Exploration Program keeps bringing scientists closer to learning if Mars could support some form of life. He says the program has shown that the planet is an important goal for future human exploration.
Charles Bolden是美国国家航天航空局（NASA）的负责人。 据他说，将来火星是否可以给人类提供生存环境，NASA的火星探测计划在慢慢地向科学家揭晓答案。 他说，这项计划已经证明，火星有可能是将来人类探险的重要目标。
BOB DOUGHTY: The Mars Reconnaissance Orbiter studied many mountain slopes across the planet's southern hemisphere. The dark lines of mountain sides are said to look like fingers. The marks appear and disappear with the seasons.
火星勘测轨道器观测了火星南半球的许多山坡。 山体侧面的黑色纹路据说看起来有点像手指。 这些印记随着季节的变更时有时无。
The marks appear when temperatures on Mars rise. They look larger as they go downhill. When it gets cold, these streaks disappear. But they are seen again on the planet during the next spring, or warming season.
温度高的时候这些手指似的印记是看不见的。 越往坡下走，印记越大。 当气温下降时，这些印记会消失不见。 但是，他们会随着火星上春季和暖季节的到来而重新出现。
CHRISTOPHER CRUISE: Alfred McEwen is lead investigator for the orbiter's High Resolution Imaging Science Experiment. He also is a professor of planetary geology at the University of Arizona in Tucson. Professor McEwen says a flow of briny, or salty, water is the best explanation for the orbiter's observations. Other spacecraft and Martian meteorites have shown that the Martian surface is salty.
Alfred McEwen是勘测仪器高清晰度成像分析的主要研究人员。 他同时也是图森亚利桑那大学行星地质学的一名教授。 McEwen 教授说，勘测器勘测到火星上出现过带咸味的流体，只有水是这种现象的最好解释。 其他太空飞船的发现和火星陨石也证明了火星表面是有盐分存在的。
The professor says the water on Mars may differ from that found on Earth. He says the Mars water might be more like a thick fluid. "Science" magazine published a report about the orbiter's findings.
McEwen 教授说火星上的水也许跟地球上的有所不同。 他认为火星上的水可能呈浓稠液体状。 《科学》杂志刊登了火星勘测仪带来的发现。
BOB DOUGHTY: Professor McEwen and his team believe that water probably flowed across ancient Mars. But whether water exists as a liquid on the Red Planet can still be debated. The iron oxide on Mars gives the planet its reddish color.
McEwen 教授以及他的小组成员都相信在远古的火星上，曾经有过水的痕迹。 但是关于这个红色星球上的水是以液态状存在与否还值得商讨。 火星上的铁元素使得这颗星球呈现红色。
Philip Christensen is an expert in geological science at Arizona State University. He says scientists have known for years that ice existed on Mars.
Philip Christensen 是亚利桑那大学从事地球科学研究的一名专家。 他说，火星上存在过冰川，这是科学界早就知道的事实。
PHILIP CHRISTENSEN: "We know Mars has a lot of ice. But this is the first time we have seen the potential for liquid water. It might be salty water. But it is still liquid. And I think that is the real key here. It is not that Mars does not have a lot of ice. But liquid water – certainly to an organism – is very, very very different than ice."
我们知道，火星上存在大量的冰。 但是火星上可能存在液态水，我们还是首次听说。 水也许是咸的。 但是，总算是液态。 我觉得这是关键。 火星上有大量的冰并不是什么大的新闻，也没那么重要。 但是液态水， 它对于有机物的作用是冰块所不能取代的。
Geology expert Lisa Pratt of Indiana University welcomes the research results. She says the discovery will help scientists plan future travels to look for life signs on present-day Mars.
印地安那大学的地质专家 Lisa Pratt 对这个结论表示非常欣喜。 她说这可以帮助科学家们为将来在火星上寻找生命的痕迹做出更好的计划。
CHRISTOPHER CRUISE: "Blue moons, you saw me standing alone." “The cow jumped over the moons” 。 “Shine on Harvest Moons”。 These expressions sound unusual. Why the choice of "moons" and not just "moon?" There is only one moon, right? Yes, there is only one, but long ago there might have been two!
“蓝色的月亮，你看我独自站立在这里。” “牛儿跃过月亮。” “光洒在这收获的月亮。” 这些话听起来可不同寻常。 为什么不说单数moon而是在后面加上了s？ 只有一个月亮不是吗？ 但是，很久以前，也许存在过两个月亮。
American and Swiss researchers say the Earth may once have had a big moon, the one that is still there, and a little moon. And then, about four billion years ago, they hit each other. The little moon exploded into rock and dust, and much of it landed on the dark side of the larger moon. The researchers call it the "big splat."
美国和瑞士的科学家声称，在过去，地球也许拥有两个月亮，一个大的，也就是我们现在看到的那个，还有一个小的。 但是，大约在40亿年前，这两个月球相撞了。 小月球被撞得粉碎，大部分的碎块掉在了大月球黑暗的那一面。 研究人员把这次事件叫做“ Big Splat”。
Scientists from the University of California at Santa Cruz and the University of Bern reported their findings in "Nature" magazine. The scientists say the little moon was very small, only about one thousand two hundred kilometers across. They say the little moon and the big moon were just fine together for one hundred million years. Then something happened and the little moon lost the battle.
来自Santa Cruz加州大学和伯尔尼大学的科学家们在 《自然》这本杂志上发表了这个结论。 科学家说其中一个月球非常小，从这头到那头大概只有一千两百公里。 大小月球相安无事地相处了大概有1亿年。 然而后来，不知由于什么原因，较小的月球消失掉了。
BOB DOUGHTY: The Earth and the moon turn in a way that keeps the dark side of the moon away from us. From earth, we see only one side. But we know what the other side looks like. Spacecraft have taken many pictures of the dark side. Those pictures show that the side of the moon we see is a lot different from its other side.
地球和月球以一定的方式旋转致使我们看不见月球的另一面。 从地球上，我们只能看见一面。 但是我们已经知道另一方到底是什么样子了。 因为宇宙飞船对黑暗的月面拍摄了许多照片。 那些照片显示，我们所看不见的月面与我们能看见的月面是截然不同的。
Our side has ridges or hills, and craters, some of them deep. But it is not nearly so "bumpy" as the dark side. Researchers think this is because the little moon crashed, fell apart, and landed on the other side. They say the dark side has a thick upper layer of soil. It also has much higher mountains than on the side we see. Some of them are three thousand meters high. And when the little moon hit the big moon, it caused a bulge. The other side of the moon sticks out into space more. Think of a children's ball that has been hit or kicked too much. That ball, and our moon, are no longer round. They are lop-sided. Pictures of the dark side clearly show this.
我们看见的月面有山脊山坡，火山口，有时候甚至是很深的火山口。 但是远不如黑暗那一面那么崎岖。 研究人员说，这可能是因为，小月球爆炸之后，其碎片跌落到了那一面。 据说，我们所不能见到的月面的上土层较厚。 同时山峰也较高。 有些甚至高达3千米。 而且，当两个月球相撞的时候，大的月面上有一部分在撞击之下凸出隆起。 黑暗的月面有很大一部分凸出在宇宙中。 就拿一个小孩的足球来说吧，假设这是个经常被踢的球。 这个球就不可能再是圆的，月亮也是同样的道理。 他们的表面会变得凹凸不平。 从月球上的黑暗面拍摄的照片就显示了这样的一种现象。
CHRISTOPHER CRUISE: You may be wondering how our moon got there in the first place. Scientists think it also resulted from a crash. Billions of years ago, they say, something very large hit the earth. It may have been as big as the planet Mars. When that happened, part of the earth was thrown out into space. Over time, these pieces of earth-rock and dust came together, and formed not one, but two moons.
你也许会好奇，月球到底是怎么形成的。 科学家认为这可能也是一场碰撞的结果。 数亿年前，据说，一个庞然大物撞击了地球。 也许这个物体有火星那么大。 当它撞击地球的时候，地球的某部分被撞飞到宇宙中。 随着时间的推移，这些地球的碎块和粉尘慢慢地形成了大小两个月球。
The American space agency plans to explore the moon further within the next year. That may help to prove the two-moon crash idea, or maybe offer something completely new. But if the latest research is correct, what is now one, was once two!
美国太空署计划在明年继续探索月球。 也许他们的发现将会应证双月之说又或者会有完全不同的结论。 但是如果这个的理论是正确的话，那么，月亮可能就真的曾经存在过两个。
JIM TEDDER: Imagine a summer night in America. A father and mother are reading the newspaper and listening to the radio. Their children are outside the house, playing and waiting for a special time. Then, just as it starts to get very dark, the magic begins.
试想一下，在夏日的夜晚。 父亲正在看报纸而母亲正在听广播。 孩子们在屋外玩耍，等待着某个特殊瞬间的到来。 随着夜的深入，神奇的事情也慢慢拉开序幕。
CHILD'S VOICE: "Look (blip) there's one over there ... (blip) and another over there! Look (blip blip blip) three more ... near the tree. Let's catch ‘em."
“快看，（虫子飞舞的声音）那边有一只……（虫子的声音）那边还有一只……呀靠近树那儿还有三只。走，去抓住它们！”
BOB DOUGHTY: What they would like to catch and put into a glass jar are coleoptera: flying beetles better known as "fireflies" or "lightning bugs."
孩子们想要抓住并放入罐子里的是一种甲虫：一种会飞的甲壳虫，以“萤火虫”著称或又称之为“电光虫”。
Scientists say there are about two thousand kinds of these insects. Most are brown. Each is only about a centimeter long. Fireflies have wings folded over their backs. When they fly, they do so in an unusual way. Some people say they fly in the shape of the letter "J." That means they fly horizontally, then drop quickly, only to rise again. But the most surprising thing about these little creatures is that they make light.
科学家说世界上大概有两千种昆虫。 大部分昆虫呈棕色。 每一种昆虫身长都只有一厘米左右。 萤火虫的翅膀是蜷放在背后的。 它们的飞行方式极其罕见。 有些人说，它们的飞行路线看起来有点像字母Ｊ。 这也就是说，萤火虫是横向飞的。 但是最让人吃惊的是这些小家伙居然能发光。
They do this by the process known as bioluminescence. Oxygen mixes with chemicals in the body of the lightning bug. Then, for a second, its belly lights up. Some produce a flash of yellow light. Others appear green or red. But why do they do this?
萤火虫发光过程被称之为“生物发光”。 氧气会和它们体内的某种化学物质发生反应。 不一会，它们的腹部就会别点亮了。 有些发黄光。 其它的可能发绿光或是红光。 但是为什么它们能发光呢？
CHRISTOPHER CRUISE: Entomologists, people who study insects, think the flashing light is an invitation to have sex. They believe the male firefly is making a signal to a female waiting in the grass. He is saying, "Look, here I am. Let's get together." If the female agrees, she will answer with a flash of her own. Studies at the University of Kansas have shown that females like males who can flash the fastest.
研究昆虫的专家说，发光可能是为了吸引异性。 他们认为雄性萤火虫发光是在向草丛中雌性萤火虫传递信息。 就像是在说，嘿，我在这儿呢 如果雌性也有意，她也会点亮自己作为回应。 堪萨斯大学的研究报告发现荧光闪得最快的雄性萤火虫对雌性最有吸引力。
In some parts of the world, fireflies act in an amazing way. Thousands of them flash their light on and off at the same time. This can often be seen in Malaysian jungles and in the American states of Tennessee and South Carolina.
在世界的某些地区，萤火虫会做出令人叹为观止的事情。 成千上万的萤火虫会同时发光。 这种现象可以在马拉西亚的丛林或是美国的田纳西和?南卡罗来纳见到。
Scientists do not know how lightning bugs are able to communicate with each other to do this. But they think it is either a call for sex, or a warning sign from the bugs to their enemies. Insects with lights carry chemicals that do not taste good. Some of those chemicals, however, are useful to people. Health researchers use them in the study of cancer, heart disease, multiple sclerosis, and cystic fibrosis.
科学家还不清楚它们是以什么方式通知同伴而进行同时发光。 但是他们觉得同时发光要么是为了求偶要么是警告有敌人来袭。 身带可导致发光化学物质的虫子并不好吃。 但是，此类的化学物对人类却非常有用。 健康专家可以用这些化学物来研究癌症，心脏病，多发性硬化症和囊性纤维化症。
BOB DOUGHTY: Fireflies live for about three years. Most of that time is spent in the ground as larvae. Some people call it a "glow worm" before it becomes a flying adult. And yes, glow worms ... larvae ... do, indeed, glow. Scientists say these little bugs only come out in warm weather, and only at night. During the day, they hide on the ground or in trees or other plants.
萤火虫的寿命大概是三年。 而在这三年里，大部分的时间它们以幼虫的状态在地上活动。 有些人将这些还不能飞的萤火虫称之为“glow worm”（发光的虫子）。 这种叫法确实是有根有据的，因为这些幼虫真的会发光。 科学家说，我们只能在天气暖和和夜里才能见到萤火虫。 白天，他们躲在地面隐僻处或是树枝上，也可能藏在其它一些植物的茎叶里。
Wherever there is light, there is heat. A common light bulb wastes ninety percent of the energy it uses in the form of heat. But a lightning bug produces "cold light." That means that most of its flash is true light. Only about three percent of its energy comes as heat.
有光就会产生热量。 一只普通灯泡会以发热的方式浪费90%的能量。 但是萤火虫的光可不会热的。 这就是说，它们大部分的光是真的（真的是在耗能量）。 只有3%的萤光转化成了热。
After three years, the life of a lightning bug's life is done. The females bury their eggs in the ground, and the birth and death cycle starts all over again, just as it has for millions of years.
三年之后，萤火虫的生命就会耗尽。 雌性萤火虫会地面产卵来进行生命的循环，以这种方式延续生命，它们已经进行了数百万年。
JIM TEDDER: Summertime in America: ice cream, baseball games, and, yes, (blip blip blip) fireflies at the close of another day.
美国的夏日意味着吃冰淇淋和看棒球赛，而在夏夜即将来临时，没错，我们还可以看萤火虫。
CHRISTOPHER CRUISE: This SCIENCE IN THE NEWS was written by Jerilyn Watson and Jim Tedder, who you also heard on our program. Our producer was June Simms. I'm Christopher Cruise.
“科学报道”节目由Jerilyn Watson和Jim Tedder 共同撰写，他们同时也是VOA 的节目主持人。 节目制作人是June Simms 。 我是主持人Christopher Cruise。
BOB DOUGHTY: And I'm Bob Doughty. Visit us at voaspecialenglish.com , where you can find transcripts and MP3s of our reports. Join us again next week for more news about science in Special English on the Voice of America.
我是Bob Doughty。 大家可以登录我们的网站voaspecialenglish.com ，在那儿我们会提供节目的文本以及新闻的MP3音频文件。 欢迎大家下次继续收听“VOA慢速英语”之“科学报道”。
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