A new study suggests that dark markings on the planet Mars represent sand – not water.

　　一项最新研究成果表明图片中深色的标记其实是沙子，而不是水。

　　Research in 2015 had suggested that lines on some Martian hills were evidence of water. Yet American scientists now say these lines appear more like dry, steep flows of sand.

　　2015年一些研究成果认为山脉线条是火星上含有水的证据。然而时至今日美国科学家认为这些线条更像是干燥的、陡峭的沙土流。

　　If water is present, they said, it is likely to be a small amount. Water in liquid form would be necessary for microbial life.

　　他们说，即使有水，也可能量很少。流体形式的水对于微生物的存活至关重要。

　　NASA, the American space agency, said more research is needed.

　　美国国家航空航天局表示，(关于火星上水的问题)还需要更多、更深入的研究。

　　Michael Meyer is the lead scientist for NASA’s Mars exploration program. He noted that the latest study does not reject the presence of water. But he admitted, "It just may not be as exciting as the idea of rivers going down the sides of cliffs."

　　Michael Meyer是美国宇航局火星探测计划的首席科学家。他指出，最新的研究并没有否定水的存在。但他承认，“最终的结果可能不会像我们预先认为的在火星上沿着悬崖的边缘存在着河流那样令人兴奋。”

　　NASA’s Mars Reconnaissance Orbiter provided the images of dark lines. Thousands have been reported on the Red Planet.

　　NASA的火星勘测轨道飞行器提供了带有黑暗线条的火星图像。据报道称这颗红色星球上有数千个黑色线条。

　　The new findings come from a team led by Colin Dundas of the United States Geological Survey in Flagstaff, Arizona.

　　这项新发现来自于美国地质调查局的Colin Dundas领导的团队。

　　His team measured 151 of these lines in 10 areas. Most of the lines end with slopes between 28 degrees and 35 degrees. These measurements are similar to active sand dunes on both Mars and Earth, the researchers noted. They said a small covering of dust that moves and sometimes becomes lighter might help explain the markings. They usually appear in the Martian summertime, then disappear until the next year.

　　他的团队在10个区域测量了151条线。大部分线路的坡度在28度到35度之间。研究人员指出，这些测量原理类似于火星和地球上的活动沙丘。小面积覆盖灰尘的移动或者质量的变轻可能更有助于解释这些标记。这些线条通常出现在火星夏季出现，然后第二年消失。

　　If these lines are dry, "this suggests that recent Mars has not had considerable [large] volumes of liquid water," the researchers wrote.

　　如果这些线是干的，“这表明最近的火星没有大量的液态水，”研究人员写道。

　　Dundas and his research team say that many questions remain.

　　Dundas和他的研究团队说现在还有很多问题没有解决。

　　To Meyer, the large number of questions is what makes Mars so fun. Scientists have long gone changed their thinking about the planet depending on the findings of the most recent studies.

　　对Meyer来说，大量的问题使火星变得如此有趣。根据最新的研究结果，科学家们早已改变了他们对火星的看法。

　　“I still think that Mars poses a great potential for having had life early on in its history,” Meyer said. “As long as that’s true, we also have a reasonable possibility of life still being on Mars. It just happens to be cryptic or well hidden.”

　　Meyer说:“我仍然认为，火星在其历史早期具有巨大的生命潜力。”“只要这是真的，我们也有可能在火星上生活。它只是碰巧是神秘的，或者隐藏得很好。”

　　NASA currently has no robotic vehicle - either on Mars or in development - with the ability to climb steep slopes. The lack of such equipment has engineers coming up with ideas like Martian helicopters or drones.

　　美国国家航空航天局目前没有能够在火星上攀登陡峭山坡能力的机器人工具，也没有在该方向投入研发。这种设备的缺失使工程师们想出了像火星直升机或无人机这样的想法。

　　“But going from a clever idea that works in your sandbox to something that goes to Mars takes a fair amount of engineering development,” Meyer said.

　　Meyer说:“好的想法可能会在实验室情况下满足你的要求，但是把这个想法应用在实际操作环境中用来去火星采获一些东西，这一步需要大量的工程技术开发。"