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Tilting poles explain Martian ice cover

点击量:   时间:2017-06-17 04:01:06

By Jeff Hecht (Image: NASA/JPL/Brown University) It has a mere dribble of water compared to Earth, yet over the past few million years Mars has experienced periodic ice ages that have shaped layers of ice lurking beneath its dusty surface. The ice cycle arises from periodic fluctuations in the tilt of its axis similar to those that cause Earth’s climate to vary from ice age to interglacial. There are important differences, though,