Earth’s spin is not as steady as it looks from the ground. As ice sheets melt and aquifers are drained, scientists now say the planet’s axis has shifted by more than 30 inches, a subtle but measurable ...

A typical desk globe is designed to be a geometric sphere and to rotate smoothly when you spin it. Our actual planet is far less perfect — in both shape and in rotation. Earth is not a perfect sphere.

Nearby planets can affect how one planet 'wobbles' on its spin axis, which contributes to seasons. Mark Garlick/Science Photo Library via Getty Images Spring, summer, fall and winter – the seasons on ...

Earth’s spin is not as steady as it looks. As ice melts and groundwater is pumped from deep aquifers to the surface, the planet’s mass is shifting, and with it the position of the rotational axis that ...