Word: marse
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Seen through the cameras of Mariner 9, the parched surface of Mars presents a scientific puzzle. Twisting gullies cut across the stark landscape like the traces of a mighty river system; yet scientists agree that there is now no free-flowing water on the Red Planet. How were the "riverbeds...
Gyroscope. The possibility of monsoons is not as farfetched as it seems. Mars has an eccentric orbit that causes large variations in the planet's distance from the sun. The Martian north pole is currently tilted toward the sun only when the planet is also at its greatest distance...
But like a spinning gyroscope, Mars slowly wobbles as it travels around the sun. Though this motion, or precession, is barely perceptible, the Martian axis leans in the opposite direction every 25,000 years, or halfway through a complete precessional cycle. When that happens, the northern polar area is angled...
If glacier-like quantities of frozen water have accumulated in either polar cap, says Smith, enough water might be released to keep the monsoons going for centuries, and possibly millenniums, until the slow precession of the planet's axis causes one pole to begin cooling enough to draw water...
Now plans for the far-ranging expeditions have been scrubbed, principally to allow the financially pressed space agency to concentrate on the Administration's multibillion-dollar space-shuttle program; one Tour mission, in contrast, would have cost about $700 million. As an alternative, NASA is considering what it euphemistically...