There is another documentary on Mars that is really interesting. I can't find it, but as soon as I have the time, I'll post a link. It show some amazing history....goes back to the Greek gods...One of them is the god of Mars, also a warring god who used lighting as a weapon. Very interesting, because some people believe that there was a cosmic war with the gods...I believe to be the fallen angels from the Bible. But, anyway, their is a huge cavern carved out by what some believe to be lighting....its as though Mars, attacked Mars with lighting, killing everyone.