Mars is the closest planet of Earth, so go to there will be the easiest planet to explore except moon(if moon is big enough to be a planet), if we successfully explore Mars, this can give us thousands of good point. Maybe you will said that the money it cost is a huge number and we definitely can use these money to find way to treat the cancer, or maybe we can help those starve people to alive. But at least, that's what some of the most innovative, intelligent minds of our age — Buzz Aldrin, Stephen Hawking, Elon Musk, Bill Nye, and Neil deGrasse Tyson — are saying. They think that those things like treat cancer or help starve people are only the things we need care in the hundred years, the thing we really need look forward like the next thousand years is to inhabit to other planets. Think about the dinosaurs, they are a classic example: They roamed the planet for 165 million years, but the only trace of them today are their fossilized remains. If human just stay on the Earth, maybe the same thing will happened on us. So this is why we need to inhabit on other planets, and the only planet can live without any dangers like meteorolite is Mars. So Mars kind like our first step to the space.