Despite the fact that Mars has an atmosphere just 1 percent as dense as Earth’s, the surface of the Red Planet still has to deal with plenty of weathering and erosion. In 2008, researchers even captured a full-scale avalanche on Mars as it plunged down a 2,300-foot slope into a valley. These types of geological events often expose the structures beneath the martian surface, revealing layers of rock, dry ice and even water ice.

　　尽管火星的大气密度仅为地球的1%，但是这里仍然存在很多风化作用和侵蚀。2008年，研究人员们甚至捕捉到了火星上的一次全面雪崩，雪沿斜坡坠入了一个2300英尺深的山谷。此类地质事件往往会暴露火星表面下的构造，揭开岩石层、干冰层，乃至水冻冰块层的面纱。

　　In a study published Thursday in the journal Science, researchers using the Mars Reconnaissance Orbiter (MRO) investigated eight steep and eroded slopes at various locations across Mars. At each of these locations, they found thick shelves of relatively pure water ice located as little as 3.3 feet below the planet’s surface. Furthermore, some of these massive ice deposits were found to be more than 330 feet thick.

　　在于周四发表在期刊《科学》上的一项研究中，研究人员们使用火星勘测轨道飞行器调查了火星不同地点八个陡峭、且被侵蚀的斜坡。在其中的每个地点，他们在火星表面下3.3英尺处发现了较纯的水冻冰块。此外，他们还发现了一些330多英尺厚的大冰块。

　　While scientists have observed water ice on the surface of the Red Planet many times before, researchers rarely get a chance to learn this much about its layering, thickness, purity and prevalence.

　　虽然科学家们曾经多次发现火星表面存在水冻冰块，但是研究人员们几乎没有机会深入了解其分层、厚度、纯度和广泛性。

　　The discovery of these large reservoirs of pure water ice adds yet another piece of evidence supporting the increasingly held theory that water ice not only exists on Mars, but also is surprisingly common. Although the ice could obviously be used as a source of water for future manned missions to Mars, scientists have a long way to go before then.

　　这些大型纯水冻冰块的发现进一步证明，水冻冰块不仅存在于火星上，而是出奇地普遍。虽然冰块明显可用作人类未来火星使命的水源，但是科学家们仍有很长一段路要走。