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Crystal Ball EARTH: Space: NASA keeps watch on a changing planet

In 2009, we saw a number of changes on Earth. The average global ocean surface temperature last summer was the warmest on record. Thin seasonal ice has recently replaced thick older ice as the dominant type of ice in the Arctic. And scientists saw that despite a quiet sun with few sunspots, Earth can continue to be bombarded with a high level of solar energy.

11 Dec 2009

Of molten iron and magnetism

Since 1999, the German satellite CHAMP (CHAllenging Mini-satellite Payload) has swirled around Earth, keeping watch as the planet’s magnetic field waxes and wanes over time. CHAMP’s continuous measurements of Earth’s field have created a finely detailed picture of how the field changes both in space and in time — and by extension, how the movement of the molten iron in Earth’s outer core ebbs and flows. And thanks to these data, researchers report, they can now track even small-scale, rapid fluctuations in the field’s strength around the planet.

28 Aug 2008