Mars

If you weighed 70 pounds on the Earth, you would weigh about 27 pounds on Mars. Mars excites scientists because its temperament is more like the Earth's than any of the other planets. Evidence suggests that Mars once had rivers, streams, lakes, and even oceans. As Mars' atmosphere slowly departed into outer space the surface water began to permanently evaporate. Today the only water on Mars is either frozen in the icy polar caps, or underground. Mars has two moons, Deimos and Phobos.