Why colonize the Moon before going to Mars?
NASA has a new Vision for Space Exploration: in the decades ahead, humans will land on Mars and explore the red planet. Brief visits will lead to longer stays and, maybe one day, to colonies. First, though, we’re returning to the Moon. Why the Moon before Mars? “The Moon is a natural first step,” explains Philip Metzger, a physicist at NASA Kennedy Space Center. “It’s nearby. We can practice living, working and doing science there before taking longer and riskier trips to Mars.” Right: The Moon, an alien world in Earth’s backyard. Photo credit: International Space Station astronaut Leroy Chiao. The Moon and Mars have a lot in common. The Moon has only one-sixth Earth’s gravity; Mars has one-third. The Moon has no atmosphere; the Martian atmosphere is highly rarefied. The Moon can get very cold, as low as -240o C in shadows; Mars varies between -20o and -100o C. Even more important, both are covered with silt-fine dust, called “regolith.” The Moon’s regolith was created by the ceaseless
