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Upright Earth

March 22, 2007

A listener asks: What would Earth be like if it didn’t tilt?


Erasing the Earth’s slant. I’m Bob Hirshon and this is Science Update.

The Earth tilts on its axis, but a listener named Tony wonders what life would be like if it didn’t. Geophysicist Clark Wilson at the University of Texas at Austin says that, first of all, there’d be no seasons. That’s because we experience summer or winter depending on whether our hemisphere is pointing toward or away from the Sun. Also, day length would never vary.

CLARK WILSON (University of Texas at Austin):
So any point on Earth would have the same amount of daylight throughout the year, basically 12 hours of daylight and 12 hours of darkness.

This would affect other critical climate systems, from the heating of ocean currents to the melting and freezing of polar ice. So it’s safe to say that if the Earth had no tilt, it would be a very different planet. Call us at 1-800-why-isit with your science question. If we use it on the air, you’ll win a Science Update mug. I’m Bob Hirshon, for AAAS, the science society.