英语听力：自然百科 行星旅行指南：火星 Mars—15

 If we have been wet, then we want to look for nutrients¹ and food sources that could support microbes. 

 

The water ice is proof of a valuable resource for any life forms still clinging(附着) beneath the surface and for future travelers. 

 

We now know that these plants that you see / stretching behind me are under land only 2 or 3 inches deep by a sheet of ice, all the way as far as you can see. Great hockey ring, if you had a hockey team on Mars, all you need is a broom. 

 

The possibility of running into Martians received another boost from a very Mars like part of our own planet, Chile’s extraordinary Atacama Desert.The Atacama is special because it is just so profoundly dry, speaking roughly, 15 times dryer² than Death Valley. It is deader than Death Valley. It is the only place on earth where Viking could have landed and searched for life in dirt on earth and not found it, and instead, found a reactive mixture of chemicals, the only place. 

 

 

Even here, in the driest corner of the driest desert on earth, life has confounded scientists, Cyano-bacteria have been found living inside the rock hard salt of a long-gone lake. 

 

This is halite, this is sodium³ chloride salt, which is colonized⁴ by Cyano-bacteria. It is dark green because they have this particular pigment⁵ protecting them from the excess of UV light. 

 

Once in a blue moon, a fleeting⁶ early morning ground fog delivers some rare humidity to the air above the desert, this precious moisture is greedily sucked into the microscopic⁷ pores of the water- hungry rock/ salt. 

 

This is a very rare event, so these bacteria are only living in an environment where liquid water is available a few hours during one year, very, very hard.

 

1 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

2 dryer   

n.干衣机，干燥剂

参考例句：

• He bought a dryer yesterday.他昨天买了一台干燥机。
• There is a washer and a dryer in the basement.地下室里有洗衣机和烘干机。

3 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

4 colonized   

开拓殖民地，移民于殖民地( colonize的过去式和过去分词 )

参考例句：

• The area was colonized by the Vikings. 这一地区曾沦为维京人的殖民地。
• The British and French colonized the Americas. 英国人和法国人共同在美洲建立殖民地。

5 pigment   

n.天然色素，干粉颜料

参考例句：

• The Romans used natural pigments on their fabrics and walls.古罗马人在织物和墙壁上使用天然颜料。
• Who thought he might know what the skin pigment phenomenon meant.他自认为可能知道皮肤色素出现这种现象到底是怎么回事。

6 fleeting   

adj.短暂的，飞逝的

参考例句：

• The girls caught only a fleeting glimpse of the driver.女孩们只匆匆瞥了一眼司机。
• Knowing the life fleeting,she set herself to enjoy if as best as she could.她知道这种日子转瞬即逝，于是让自已尽情地享受。

7 microscopic   

adj.微小的，细微的，极小的，显微的

参考例句：

• It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
• A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。