There are two main reasons for this: It would increase dramatically the risk of forward contamination of the Mars surface with our earthly microbes, which would ruin our unique chance to study a pristine Mars. In order to stay alive in space, people need lots of things: food, oxygen, shelter, and, perhaps most importantly, fuel. Humans aren’t the only things you want to send on a manned Mars mission.
There are far fewer vital resources on the Moon, and a Moon day takes a month. The race is on though to send human explorers to Mars and a number of Earth-bound projects are trying to learn what life would be like on the red planet… After the Earth, Mars is the most habitable planet in our solar system due to several reasons: The only other two celestial bodies in orbits near the Earth are our Moon and Venus. There are lots of good reasons to send humans to Mars. Humans to Mars is Affordable and Achievable: Recent workshops and studies have also shown that missions to Mars are both achievable and affordable. Going to Mars is hard and it is even harder for humans because we would need to pack everything to survive the trip to our neighbouring planet and back. You could argue that space exploration is simply a part of our curious nature as humans and that Mars is the new frontier. Designing a Mars mission would be easier if we could use resources that are already available locally. It also does not have an atmosphere to form a barrier against radiation. NASA will not require a …
Because Mars has no magnetic field, humans would receive whopping doses of cosmic radiation -- not a problem on Earth, where the planet's magnetic field works to block it out.