Is Mount Everest really the highest point on earth?

Mount Everest is well known as the highest spot above sea level on our planet and is likely to remain so for a long time; that is, unless you reconsider the definition of "highest."

When measured as the either the spot on earth closest to space, or the spot on the surface furthest from the center of the earth, Mount Everest is in fact NOT the highest point -- Mount Chimborazo in Ecuador is!

The Earth is in fact not a perfect sphere. It is more like a beach ball that someone sat on: It has a slightly distended middle.

Mathematicians call this an "oblate spheroid," which means there is a bulge that circles the Earth just below the equator, so anyone standing in that part of the world is already standing "higher," or closer to outer space, than people who aren't on the bulge.

Mount Chimborazo, in the Andes, is a 20,000-plus-foot peak sitting on top of a bulge on the Earth. Mount Everest is a 29,000-plus-foot peak sitting lower down on that same bulge. Because Chimborazo is a bump on a bigger part of the bulge, it is higher. In fact, it's 1.5 miles higher than Everest!

Perhaps more interesting: using this same logic, Death Valley -- the lowest point below sea level in North America -- is in fact higher than Mount McKinley, the highest point above sea level in North America!

In fact, the Dead Sea -- the lowest point on the terrestrial Earth -- is also higher than Mount McKinley!

Listen to NPR's audio story here.