Recently, I heard something very interesting from a friend who spoke with a NASA scientist. He stated that NASA has devised a way to use anti-matter in actual spacecraft reactors, and that combining this new source of propulsion with other recent advances in technology could yield a speed that would bring the arrival time to Mars down from its current 18 month period, to seven minutes! I know very little about the reality of antimatter and how it can be used in our "solid material" world. Kyle (my friend) didn't know very much either about the specific functions of antimatter. If one of you could enlighten me on a few antimatter topics, i.e. the principles behind it, how it can be used for propulsion, and the possible danger(s) it could pose, I would be grateful. So basically, what, how, and why?