Horizon - Life On Mars 火星生命 - 6
For Mars to have rivers, it must once have had streams, rain, clouds and an atmosphere, a planet just like the Earth today-if these were rivers. They had to be sure.
The answers would come in 1998 with the launch of Mars Global Surveyor. It was equipped with the latest high-resolution electronic cameras. Sections of the valleys were revealed in fantastic detail. Some valleys had been eroded 1 and filled in with sand. It was impossible to say how they'd been formed. They could have been carved by water, or soil, or carbon dioxide. Then, after they'd searched through thousands of images they found this- a winding 2 valley, two kilometers wide, and at a bend in the canyon 3, a tiny channel, the unmistakable trace of an ancient river.
This is the best evidence we have that climate in the past was different from what it is today.
Only a river would leave a meandering 4 trace like this. Only a river would leave the traces of silt 5 they saw in the bend, and only water could carve the winding channel feeding into it. But they soon found more than just a few rivers. They discovered evidence that water had once existed on Mars in colossal 6 quantities.
The evidence came from another probe that reached Mars in 1997. It landed in an enormous channel and sent back images of huge boulders 7 scattered 8 around the Martian surface. Scientists were puzzled. What could this strange pattern signify? One man looking on knew exactly what those scattered stones meant-Jim Rice.
Mars Global Surveyor:U. S. mission to Mars launched in 1996. Main instruments include a camera, laser altimeter, thermal 9 emission 10 spectrometer, and magnetometer. During the primary mission, the spacecraft circled the planet once every 118 minutes at an average altitude of 378 kilometers (235 miles). The extended mission phase began February 1, 2001. The spacecraft may function eventually as a communications satellite to relay data back to Earth from surface landers launched as part of future Mars missions
meander:to follow a winding and turning course
meandering:winding
- A winding lane led down towards the river.一条弯弯曲曲的小路通向河边。
- The winding trail caused us to lose our orientation.迂回曲折的小道使我们迷失了方向。
- The Grand Canyon in the USA is 1900 metres deep.美国的大峡谷1900米深。
- The canyon is famous for producing echoes.这个峡谷以回声而闻名。
- The village seemed deserted except for small boys and a meandering donkey. 整个村子的人都像是逃光了，只留下了几个小男孩和一头正在游游荡荡的小毛驴。 来自教父部分
- We often took a walk along the meandering river after supper. 晚饭后我们常沿着那条弯弯曲曲的小河散步。
- The lake was almost solid with silt and vegetation.湖里几乎快被淤泥和植物填满了。
- During the annual floods the river deposits its silt on the fields.每年河水泛滥时都会在田野上沉积一层淤泥。
- There has been a colossal waste of public money.一直存在巨大的公款浪费。
- Some of the tall buildings in that city are colossal.那座城市里的一些高层建筑很庞大。
- Seals basked on boulders in a flat calm. 海面风平浪静，海豹在巨石上晒太阳。 来自《简明英汉词典》
- The river takes a headlong plunge into a maelstrom of rocks and boulders. 河水急流而下，入一个漂砾的漩涡中。 来自《简明英汉词典》
- Gathering up his scattered papers,he pushed them into his case.他把散乱的文件收拾起来，塞进文件夹里。