ENCELADUS We’ll travel to one of Saturn’s 53 moons for the next comparison. Ice covers it. Yet cameras from the Cassini spacecraſt captured surprising images. As many as 100 geysers spray icy water from cracks near the moon’s south pole. T ey release 250 kg of water vapor per second. We have geysers on Earth, too. At El Tatio in


Chile, for example, volcanic activity heats water deep under the ground. T e water hisses as it boils to the surface. T en, whoosh! Hot water shoots up to a meter into the air. Clouds of steam rise from 80 geysers. T ere’s no volcanic activity on Saturn’s icy


moon. Instead, we think the geysers erupt when Saturn’s gravity tugs on the moon. T is opens cracks on the icy crust. Water from a subsurface ocean sprays out. Data from a space telescope shows that some spray blasts so far into space that it falls on Saturn. T ere, it forms a cloud of water vapor 58,000 km thick. It’s the only moon we know of that “rains” on its planet!


Volcanic activity heats the water that forms these geysers in Chile.


These geysers spray icy water thousands of kilometers above Saturn’s moon Enceladus.


16 NATIONAL GEOGRAPHIC EXTREME EXPLORER


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