Jimmy Brooks, age 12, Erin, Tennessee, for his question:

What is the diameter of the earth?

The earth is not quite a perfect sphere. It bulges a little at the equator. So the diameter through the poles is not quite the same as the diameter through the equator.

The diameter at the equator is 7926.677 miles. The diameter through the poles is 7899.988 miles, a difference of 26,689 miles This is not very much, but it means that our earth is not a perfectly round ball.

You may be wondering why this bulging waistline does not show on your beautiful gift globe. The reason is that in such a small scale model of the earth, the difference is not enough to make any difference. On your globe, the difference between the diameter at the poles and the diameter at the equator would be equal to the thickness of a few sheets of note paper.