[A_C_Slater]

I read in National Geographic that Terraforming of Mars is possible (to make Earth-like) by releasing large amounts of Hydrogen into the atmosphere. This will take hundreds of years.

As far as the Voyager probe, if humans did try to tavel to the next solar system they would be traveling much faster than that probe. There is a theoretical design that I've seen in my college astronomy book regarding a ship that could travel about 1/4 light speed.

The ship has a giant plate shaped disc on the the tail end and a theory is that by igniting hundreds of hydrogen bombs directly behind the plate then the explosions will propel the ship at an astronomical speed. I think it was estimated that it would take 40 years to reach Alpha Centauri (a triple star system) at this ship's speed, but there is no gurantee that there's a Terran planet in that solar system. But I figure by that time this will be known.

Also, the ships cost would be about the yearly GNP of the entire planet.