Where, Oh Where Has Mars’ Water Gone?
(From the September/October 1999 issue of StarDate magazine)
Mars Climate Orbiter, the first craft in the next wave of robotic missions to Mars, is scheduled to enter orbit around the red planet on September 23. For one Mars year (22.5 Earth months), it will monitor Martian weather and surface conditions, providing a clearer understanding of the planet's climate -- past as well as present.
Climate Orbiter's first mission will be to serve as a relay station for Mars Polar Lander, which will land near the south pole in early December. Its mission, too, is to study the Martian climate.
Early next year, the craft will begin its own scientific mission. Its camera will keep an eye on Martian clouds, and on the planet's surface. Another instrument will measure temperatures, cloud thickness, and the amount of dust and water vapor in the atmosphere. These observations will help astronomers understand present-day Martian climate -- especially how water moves from one place to another. The observations should also help explain the planet's ancient climate.
Scientists are almost certain that Mars was once a fairly wet, warm planet. Powerful rivers flowed across its surface, and water pooled in ponds and lakes. A detailed relief map of Mars compiled by Mars Global Surveyor suggests that an ocean may have covered much of the plains of the northern hemisphere, which are lower than the rugged highlands of the southern hemisphere.
Today, though, Mars is dryer than the most arid desert on Earth. Some water is frozen in the ice caps at the planet's north and south poles or into the soil, and a few wisps of ice-crystal clouds float above the red landscape. But there is not enough water to fill the planet's ancient oceans and rivers. Scientists hope that Climate Orbiter's observations will help explain where the water went. -- — Damond Benningfield
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