“Or too much sun.” Juma works a small plot ... The magazine thanks The Rockefeller Foundation and members of the National Geographic Society for their generous support of this series of ...

This story appears in the December 2009 issue of National Geographic ... not an Earth at anything like our Earth's 93-million-mile distance from its star. The Earth tugs the sun around at only ...

This story appears in the September 2009 issue of National Geographic magazine ... solid part of the Earth is 120,000 terawatts. From this perspective, energy from the sun is virtually unlimited." ...

The Earth's interior is composed of four layers, three solid and one liquid—not magma but molten metal, nearly as hot as the surface of the sun ... which slowly move around, colliding to ...

This axis of rotation is tilted 23.4 degrees away from the plane of Earth's orbit around the sun, giving us seasons. Whichever hemisphere is tilted closer to the sun experiences summer ...

“Or too much sun.” Juma works a small plot ... The magazine thanks The Rockefeller Foundation and members of the National Geographic Society for their generous support of this series of ...