Mars has long been the focus of a search for life, but many people are also discussing creating colonies on the Red Planet. One of the main reasons why Mars is being considered as a potential colony is its similarities with Earth. Mars’ days are only about 40 minutes longer than a day on Earth. Additionally, Mars’ seasons are similar to the Earth’s seasons – just twice as long. Mars even has a slight atmosphere. Additionally, Mars is closer than the other planets – except for Venus – which would make the process of colonizing it much easier.
There are still many differences though. For instance, the gravity on Mars is only about 40% of the Earth’s gravity. Additionally about 95% of the planet’s atmosphere is carbon dioxide, the atmosphere cannot protect from people on the planet from harmful radiation, and the temperatures reach -63°C. Even with its problems, Mars is considered the easiest planet to make habitable. The main two things people would need are breathable air and water.
Numerous locations on the planet could be considered for colonization. Although scientists have discovered large amounts of water at the poles, they think that water can also be found at other locations on the planet. Thus, the poles are not considered the best spot for a colony, especially since they experience periods of constant light and darkness like the Earth’s poles do.
If Mars was going to be turned into a colony, the planet would need to be terraformed. Another concern regarding building a colony is the cost. Not only would materials have to be transported to the planet, but the planet would also need to be made habitable. As an alternative to spacecraft, a space elevator between Earth and Mars has been proposed. There is a good deal of debate regarding what could be produced from a Mars colony. The colony may be able to produce some of the local resources it needs to survive, although the infrastructure would likely take a while to build.
Despite the difficulties, some scientists feel that it is only a matter of time until Mars is colonized. There are a number of groups dedicated to advocating the colonization of Mars, such as the Mars Society. If a colony on Mars is in the future, then it is still quite a ways away. NASA has not actually had a manned flight to the planet yet, although there are tentative plans for such missions in the future.
Astronomy Cast has an episode on humans to Mars.