The streaks range from 0.5 yards to 5 yards wide and stretch hundreds of feet , far smaller than previously detected gullies .
这些条纹有0.5码到5码宽,数百英尺长,比之前观测到的冲击峡谷要小得多。
Even gullies and dry stream beds may have water just below the surface .
甚至峡谷和干涸的河床表面以下也可能有水。
The gullies may have been carved by liquid water millions of years ago , when mars was warmer and wetter .
这些水沟可能是几百万年前由液态水冲刷而成,那个时候的火星要比现在更加温暖和湿润。
Air-cushion vehicles can travel above water with waves reaching 4 m in height , two-meter deep gullies and two-meter high bushes . Travelling over bogs is also possible .
气垫船能在浪高四米的水面上行驶,两米深的沟壑、两米高的灌木丛甚至沼泽地带也都可以通行。
Farmers frequently level off such gullies after harvesting in the fall , he said , and then replant the same low-lying areas year after year , leaving them susceptible to further erosion .