The Invisible Mountains of Earth

The dwarf planet <a href="http://en.wikipedia.org/wiki/Haumea" rel="noopener ugc nofollow" target="_blank">Haumea</a>, for example, has an equatorial radius that’s estimated to be double its polar radius, thanks to its incredibly rapid rotation. Since the poles are closer to the center of the planet — and hence, closer to the center of planet’s dense mass — the gravitational force is stronger there, and weaker at the equator. Although it’s less pronounced on Earth, the same thing happens here. On Earth, the gravitational acceleration at the North Pole is slightly above average at 9.83 m/s^2, while at the equator, it’s “only” 9.79 m/s^2. Not a huge difference, but a measurable one: enough to throw off a pendulum clock by over an hour over the course of a month! <a href="https://medium.com/starts-with-a-bang/the-invisible-mountains-of-earth-c6bb43cf9803">Learn More</a>