2022年11月07日 VOA慢速英语：火星上大型古代海洋的新证据

Researchers say they have discovered new evidence that Mars once had a large northern ocean. The finding adds to existing evidence that ancient Mars had the right conditions to possibly support some form of life.
研究人员说，他们发现了火星曾经有一个巨大的北海的新证据。这一发现增加了现有证据，表明古代火星具有可能支持某种生命形式的合适条件。
 
Today, Mars has a cold, desert climate. Any water is believed to be in the form of ice because of the planet's extremely cold temperatures. But there is a rich amount of evidence suggesting that rivers, lakes and even oceans once existed on Mars.
今天，火星拥有寒冷的沙漠气候。由于地球极冷的温度，任何水都被认为是冰的形式。但有大量证据表明，火星上曾经存在河流、湖泊甚至海洋。
 
For example, a 2015 study by the American space agency NASA suggested that 4.3 billion years ago, Mars likely had an ocean that covered nearly half of Mars' northern hemisphere.
例如，美国航天局 NASA 2015 年的一项研究表明，43 亿年前，火星的海洋可能覆盖了火星北半球的近一半。
 
Another NASA-supported study, published in January, estimated that three billion years ago, the climate in much of the planet's northern hemisphere was very similar to present day Earth. The study noted that at the time, Mars likely had a much thicker atmosphere than today and had an active, northern ocean.
另一项由美国宇航局支持的研究于 1 月发表，估计 30 亿年前，地球北半球大部分地区的气候与今天的地球非常相似。该研究指出，当时火星的大气层可能比今天厚得多，并且有一个活跃的北海。
 
Now, two American researchers have released a set of maps they say provides new environmental evidence of a large ancient ocean on Mars' low-lying northern hemisphere.
现在，两名美国研究人员发布了一组地图，他们说他们提供了火星低洼北半球上巨大古老海洋的新环境证据。
 
The team collected data from satellite images of Mars. They then combined these images to create topography maps of the planet's northern hemisphere.
该团队从火星的卫星图像中收集数据。然后，他们将这些图像结合起来，创建了地球北半球的地形图。
 
Using these maps, the researchers said they were able to piece together evidence of shorelines that sat at the edge of a huge body of water about three-and-a-half billion years ago.
研究人员表示，使用这些地图，他们能够拼凑出大约 35 亿年前位于巨大水体边缘的海岸线的证据。
 
The scientists recently published their findings in the Journal of Geophysical Research: Planets.
科学家们最近在《地球物理研究杂志：行星》上发表了他们的发现。
 
The team said it used software developed by the United States Geological Survey to map data collected by spacecraft operated by NASA. The research uncovered more than 6,500 kilometers of ridges that are believed to have been formed by flowing water.
该团队表示，它使用美国地质调查局开发的软件来绘制由美国宇航局运营的航天器收集的数据。该研究发现了超过 6,500 公里的山脊，据信这些山脊是由流动的水形成的。
 
The scientists say the ridges likely represent the leftover evidence of eroded river systems and an ancient ocean floor. The team said its research also suggested large levels of sediment, providing further evidence of a large ocean.
科学家们说，这些山脊可能代表了被侵蚀的河流系统和古老的海底的遗留证据。研究小组表示，他们的研究还表明存在大量沉积物，这为大洋提供了进一步的证据。
 
Benjamin Cardenas was a co-writer of the study. He is a professor of geosciences at Penn State University in Pennsylvania. He said in a statement the area of Mars studied – now known as Aeolis Dorsa – contains "the densest collection" of water-formed ridges on the planet.
本杰明·卡德纳斯是该研究的合著者。他是宾夕法尼亚州立大学的地球科学教授。他在一份声明中说，所研究的火星区域——现在被称为 Aeolis Dorsa——包含地球上“最密集的水形成山脊”。
 
Cardenas said the study's findings demonstrate the possible ocean in that area of Mars was very active and interesting. "It was dynamic. The sea level rose significantly," he said. "Rocks were being deposited along its basins at a fast rate. There was a lot of change happening here."
卡德纳斯说，这项研究的结果表明，火星该地区可能存在的海洋非常活跃和有趣。“这是动态的。海平面显着上升，”他说。“岩石正以极快的速度沿着盆地沉积。这里发生了很多变化。”
 
Cardenas added that areas on our own planet containing water-formed ridges and sediment provide researchers with much useful information about an area's climate and life forms. "If scientists want to find a record of life on Mars, an ocean as big as the one that once covered Aeolis Dorsa would be the most logical place to start," he said.
Cardenas 补充说，我们星球上包含水形成的山脊和沉积物的区域为研究人员提供了有关该地区气候和生命形式的许多有用信息。“如果科学家想在火星上找到生命的记录，那么像曾经覆盖 Aeolis Dorsa 的海洋那么大的海洋将是最合乎逻辑的起点，”他说。
 
The team noted that the major goal of NASA's Mars explorer, Curiosity, is to look for signs of ancient life on the planet. Currently, Curiosity is operating within the planet's Gale Crater, which is in the southern hemisphere of Mars. In the past, researchers have also found evidence of past water systems around Gale Crater.
该团队指出，美国宇航局火星探测器好奇号的主要目标是寻找火星上古代生命的迹象。目前，好奇号正在火星南半球的盖尔陨石坑内运行。过去，研究人员还发现了盖尔陨石坑周围过去水系统的证据。
 
 
In addition to providing more evidence of a large ocean, Cardenas suggested the new study also provides useful information on Mars' ancient climate and developmental history. "Based on these findings, we know there had to have been a period when it was warm enough and the atmosphere was thick enough to support this much liquid water at one time," he said.
除了提供更多关于大海洋的证据外，卡德纳斯建议这项新研究还提供了有关火星古代气候和发展历史的有用信息。“根据这些发现，我们知道一定有一段时间它足够温暖，大气也足够厚，可以同时支持这么多液态水，”他说。