1. Another prominent feature of Mars's surface is cratering. 火星表面的另一个显著特征是它的凹凸不平。
2. As on the Moon, the extent of large impact cratering serves as an age indicator for the Martian surface. 和在月球的一样，大型撞击陨石坑的范围之广可以显示出火星表面的年龄。
3. The surface of Mars shows a wide range of geologic features, including huge volcanoes—the largest known in the solar system—and extensive impact cratering. 火星表面显示出广泛的地质特征，包括巨大的火山——太阳系中已知的最大的火山——和广阔的撞击坑。
4. As on the Moon, the extent of large impact cratering (i.e. craters too big to have been filled in by erosion since they were formed) serves as an age indicator for the Martian surface. 与月球上相同，那些巨大陨石坑的范围（例如，那些巨大到自形成后尚未被尘埃填满的陨石坑）标志着火星表面的年龄。
5. "That's a problem," comments cratering specialist h. “这是一个问题，”亚利桑那大学的环形山专家H。
