Mars like i heard is also suitable for humans and other living organism too but the big question remains that are we really ready for that yet? How do people cope without gravitational force? Without going too deep, i think its imppossible for humans to do without gravity.
Mars has about a third of the gravity that Earth has. If you weigh 198 pounds on Earth, you would weigh about 66 pounds on Mars.
Because the Mars atmosphere is so small and thin, there is little protection from cosmic rays. This means that any microbes in the soil of Mars would be killed off by radiation. Why is this important? Metallic minerals are poison to plants that try to grow in them. Plants need microbes to turn the soil into ionic minerals of the kind that they can absorb to live. Plants won't grow on Mars. If they DO grow on Mars, it will be because the microbes are brought in, and are protected from the radiation somehow.
Mars is a hostile environment to people. It will take many years to make Mars habitable for people so that they can live out in the open. With the technology that we have, it might be impossible. People would have to live in biospheres to start. Here on Earth, we haven't had much long-term success with biospheres, so how could we ever live with them on Mars?