   neutral   I'm not sure NASA has built any portable habitats for extended stays on Mars, but they have looked at various designs.     neutral   One of the most exciting things about Mars is that there could have bean life on it. What are your personal opinions on the life on Mars theory?  
    neutral   Well, I'm not really an expert in this area, but my understanding is that anything is possible. It's just that it is so hard to determine what went on 4.5 billion years ago.     neutral   But maybe there is a chance of gradually improving the surface and atmosphere of Mars so it may be inhabitable by humans.  
    neutral   I'm skeptical. Mars is made of rocks containing silicon, iron, and various minerals. It also has an atmosphere of carbon dioxide. It is so different from what we have on earth, you know.     neutral   
 Yes, exactly. And then all these questions about how much water would actually remain after having done all
 Yes, absolutely! So far into history we cannot compare them because their geological makes up is too