Whoa!!! Let's not try smashing a comet into poor ole' Mars before we know what is there and what has happened to it already! I'm not TOTALLY against IDEAS, but lets get some better idea of what we are really dealling with in the first place??? There might be hints up there of the changing of our solar system that we just haven't had a chance to think of yet. Besides, at an average temperature of -65 (if I remember right?) the melting of poor old Halley's comet might be slow? And why isn't there water showing all around on Mars today? It appears that it was there in places long ago. Where is it now? Let's study a bit before we try major, expensive moves that might do no more than knock Mars out of it's orbit and cause problems for us all??? :blink: