英语听力:自然百科 行星旅行指南:火星 Mars—18(在线收听

 There is no room to screw up on a trip like this, mental or otherwise. Once on Mars, you are likely to be stuck there for a year or more, waiting for a window of opportunity to ride home. And unlike a robot, the hopes and fears of the whole planet will be riding with you. 

 
I think that humans are going to do a better job of exploring Mars ultimately than robots ever can. 
 
Robots move really slowly, what is in every opportunity that had done in 5 years on Mars, 2 astronauts can probably have done in a week. 
 
As fast and as smart as we are, we still need mechanical help to scout(侦察) the course for Mars, the next robot rolling on to red dirt will be aptly named Curiosity. 
It is the size of a small car and it has a nuclear power source, so you don’t have to worry about dust accumulating on solar or radar and things like that, and most importantly, it has the capability to look for trace quantities of organic molecules, so we have gone beyond now looking for evidence of habitability to actually looking for evidence of the building blocks of life. 
 
Whether it is alive or dead, a trip to this red planet has a lot to teach us about our lonely blue one and the universe beyond. 
 
Now if you have 2 planets that are next to each other in the same solar system, they both have independent origins of life, you would have to conclude that the chance of having life all over the universe indeed, even in other places in our solar system would be very high and you can basically go to the bet and bet on it. 
 
We are not going to Mars just to search for life, we are going to Mars to search for a second genesis (起源)of life. We’d like to find something that is different from us that doesn’t have same genetic history and genetic code that we have, and for my point of view, the more alien the better. 
 
Now the second possibility is that we find life on Mars but, my goodness, it has a genetic code exactly like us, it uses DNA.  It is too coincidental. This is representing our cousins. Life, either arose on earth and went to Mars, or actually, more likely the life originated on Mars, and it was transported on a meteorite or a comet to the earth early on and in fact, our home planet is Mars.
  原文地址:http://www.tingroom.com/lesson/zrbaike/2012/260589.html