英语听力:自然百科 行星旅行指南:火星 Mars—3(在线收听

 Could life have been forged in the same way on both planets? When we sent the first probe to investigate in the 1960s, almost anything was possible. 

 
“Originally in the popular imagination we thought that Mars might be inhabited by whole civilizations, building canals and so on. And then the Mariner fly-by missions really painted the very grim, black and white view of Mars as being barren.” 
 
The pictures and data recorded by Mariner 4 reveal Mars to be a cold, barren planet.
 
(SCS is close to vertical. )
 
Still NASA was eager to look for signs of life. In 1976, the Viking spacecraft arrives from earth for our first close encounter, and there are still hopes of a welcoming committee. But both Viking spacecrafts send back photos of nothing but rocks and sand. 
 
“We had cameras, so obviously if there was a yacca plant or I was hoping there’ll be a free way in the distance, but what the main thrust of Viking was actually was some chemical laboratories, and they looked for the chemical signs of life.” Even the dirt seems devoid of life.
 
“There was always a chance that when we were so busy looking for microbes there could be a large organism looking over their shoulder that they completely missed. But now we have enormous amount of imagery that shows nothing like a large organism. There’re no Catharine around, there’re no bison, there’re no palm trees.”
 
It seems Mars is not the kind of planet that gives up its secret easily. But if you dig a little deeper, you’ll soon find that this is a world worthy of a closer look.
  原文地址:http://www.tingroom.com/lesson/zrbaike/2012/260573.html