Terraform literally means "earthlike" and brings to mind space age dreams of planet colonization. Terraformed settlements, however, are much more than something out of a sci-fi movie. Over the past few decades, impressive advancements have been made in the creation of terraformed settlements. While the image of humans living an Earth-like existence in other planets still raises eyebrows, the truth is that scientists are closer than ever to make it a reality.

Terraformed settlements require a minimum of livable conditions to exist. This means that planets that are too close to the sun, and therefore too hot, are worthless. This is the case with Venus, for example. While close enough to Earth to allow for space travel, the planet has an average temperature of 900° Fahrenheit (482° Celcius). Other planets or moons, like Jupiter's moon Europa, are on the extreme opposite, with temperatures so low that animal life cannot be supported. Mars and the Moon, however, are good candidates for terraformed settlements, as they have more manageable temperatures and season-like periods along the year. Mars, especially, seems to share some common characteristics with Earth, including the existence of oxygen in the air and the presence of ice, both mandatory to make life possible.

Scientists believe the idea of creating terraformed settlements in space, especially Mars, should be approached long before humans move there. By creating a giant greenhouse effect on the surface, NASA believes it would be possible to transform Mars atmosphere enough to support human life in just a couple of centuries. Terraformed settlements could be established long before that if humans would agree to use breathing gear at all times.

A form of terraformed settlements has been used for decades in space stations. The International Space Station (ISS), currently being built by 15 countries working together, will provide astronauts and scientists with a closer chance of exploring space. While life aboard the ISS will not be exactly like on Earth, the ISS will allow its inhabitants to recycle water, dispose of waste effectively, prepare their own food in the station's kitchen, and produce their own oxygen.