In our solar system, Mars is the fourth planet from the sun. It is, in many ways, similar to our own planet. Mars has clouds, wind, ice caps, canyons, volcanoes, and 24-hour days. One year on Mars lasts about 687 Earth days, twice the length of our own year. Because water (in the form of ice) is present on Mars, it is considered the most likely candidate for hosting life - human or indigenous - beyond the earth...