Moon and Mars

StarDate: August 14, 2009

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After our own Earth, the friendliest planet in the solar system is Mars. Even so, when people start exploring the Red Planet, it'll take some getting used to.

A Martian day is about 40 minutes longer than an Earth day, for example. That's not much, but it still means that explorers will need to find a way to reset their "internal clocks" if they're going to follow the cycle of the Sun.

Martian gravity is only about 40 percent as strong as Earth's gravity, so people will be able to jump higher and lift more massive objects. They'll develop a different gait for walking, just as the Apollo astronauts did on the Moon. But they'll need some vigorous exercise to make sure they don't lose muscle mass and bone density.

The Martian atmosphere is different, too. It's only about one percent as thick as Earth's atmosphere. It doesn't do much to hold on to the Sun's heat, so temperatures seldom climb above zero, even during summer, and during winter nights they can plunge to 200 below. And the air contains some of the powdery Martian soil, so the skies look pink or orange.

Another difference is that Mars has not one moon, but two. More about them tomorrow.

In the meantime, look for Mars near our own Moon early tomorrow. They're well up in the east at first light. Mars looks like a bright orange star below the Moon. Don't confuse it with the true star Aldebaran -- which is also orange -- about the same distance to the Moon's right.

Script by Damond Benningfield, Copyright 2009

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