VOA慢速英语2020 新证据表明火星上存在古老河流（在线收听）

New Evidence Found of Ancient Rivers on Mars

Scientists say they have found the most detailed evidence yet of long-flowing, ancient rivers on Mars.The discovery supports existing evidence that Mars –

科学家们表示，他们发现了迄今为止最详细的证据，证明火星上存在古老的河流。这一发现支持了现有的证据，

which today is dry and cold – was once a water-rich planet.The researchers say their findings suggest rivers may have flowed on the surface of Mars for hundreds of thousands of years.

即证明了如今干燥且寒冷的火星曾经是一个富含水的行星。研究人员表示，他们的发现表明，河流可能在火星表面流淌了数十万年。

The evidence came from new satellite pictures of the Martian surface.These images were captured by a camera on NASAs Mars Reconnaissance Orbiter.The camera is able to take detailed pictures of the surface while orbiting the planet from about 400 kilometers away.

证据来自火星表面的最新卫星图像。这些图像由美国国家航空航天局（NASA）的火星勘测轨道飞行器搭载的摄像头拍摄的。这个摄像头能在距离火星约400公里的轨道上拍下详细的火星表面图像。

A team of scientists studied the images, which showed a rocky area within the planets Hellas Impact Crater.An impact crater is formed when a space object crashes into a planet or moon.The Hellas Impact Crater, in the southern Martian hemisphere, is one of the largest formations of its kind in the solar system.

一组科学家研究了这些图像，图像显示了火星海勒斯撞击坑内的岩石区域。撞击坑是太空物体撞上行星或月球时形成的。海勒斯撞击坑位于火星南半球，是太阳系中最大的撞击坑之一。

The team was led by Francesco Salese, a geologist at Utrecht University in the Netherlands.The research results were recently published in a study in Nature Communications.

该小组由荷兰乌得勒支大学的地质学家弗朗西斯科·萨莱斯领导。研究结果于最近发表在《自然通讯》期刊上。

Salese said the scientists studied sedimentary rocks from a 200 meter high rocky cliff.Sedimentary rocks form when sediment, transported by water or wind, settles and forms solid rock.

萨莱斯说，科学家们研究了200米高的岩石悬崖上的沉积岩。沉积岩指沉积物经水或风的搬运通过沉淀形成的固体岩石。

"These are sedimentary rocks, 3.7 billion years old,and were formed by rivers that were likely active for over 100,000 years of Martian history," Salese said in a statement.

萨莱斯在一份声明中表示，“这些是沉积岩，有37亿年的历史，由可能在火星历史上活跃了10万多年的河流形成。”

"OK, it is not like reading a newspaper,but the extremely high resolution imagery allowed us to ‘read the rocks as if you are standing very close to the cliff," he added.

“这不像看报纸，但超高清图像使我们得以‘看到’岩石，就好像我们站在距离悬崖非常近的地方。”他补充说。

Salese said even without the ability to examine the cliff area up-close on Mars,the pictures show strong similarities to sedimentary rocks found on Earth.

萨莱斯说，即使没有能力近距离观察火星上的悬崖区域，这些图像也表明火星上的沉积岩与地球上发现的沉积岩极为相似。

The researchers created three-dimensional, or 3D, images of the area to get a more detailed understanding of it.The pictures suggested that some ancient Martian rivers were several meters deep.

研究人员创建了该地区的三维图像（3D），以便对其有更详细的了解。这些图像表明，火星上一些古老河流有数米深。

William McMahon is another geologist who was part of the investigation team.He said sedimentary rocks have long been studied on Earth to learn what conditions were like on our planet millions, or even billions of years ago.

威廉·麦克马洪是该调查小组中的另一名地质学家。他说，人们长期以来一直在研究地球上的沉积岩，以了解数百万甚至是数十亿年前地球的状况。

"Now we have the technology to extend this methodology to another terrestrial planet, Mars,which hosts an ancient sedimentary rock record which extends even further back in time than our own," McMahon said in a statement.

麦克马洪在一份声明中说:“现在我们拥有了将这种方法推广到另一个类地行星—火星的技术，火星上保存着一份古老的沉积岩记录，其时间甚至比我们地球的记录还要久远。”

Another leader of the team was Joel Davis, a researcher with Britains Natural History Museum.He said scientists had never before been able to examine such a rock formation with such great detail.

研究小组的另一名领导者是英国自然历史博物馆的研究员乔尔·戴维斯。他表示，科学家以前从未能如此详细地研究这种岩层。

Davis said the discovery is "one more piece of the puzzle in the search for ancient life on Mars."He added that it also provides new evidence of how much water existed on Mars in ancient times.

戴维斯说，这一发现是“是在探索火星古代生命之谜进程中遇到的又一块拼图”。他补充说，这也为火星在远古时期存在多少水提供了新的证据。

"The rivers that formed these rocks werent just a one-off event - they were probably active for tens to hundreds of thousands of years," Davis said.

戴维斯说：“形成这些岩石的河流不只是一次性事件，它们可能活跃了几万到几十万年。” 

Salese added that the findings show Mars had an environment able to support large, flowing rivers for extended periods of time.

萨莱斯补充说，这些发现表明，火星拥有能长期维持大型河流流动的环境。 

"This kind of evidence, of a long-lived watery landscape,is crucial in our search for ancient life on the planet," Salese said.

萨莱斯说：“证明存在长期水景的这种证据，对我们在火星上寻找古老的生命至关重要。” 

Im Bryan Lynn.

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