Weird Science

Gravity Varies Around the Earth

It turns out gravity isn’t the same everywhere, and a European space probe shows us what the Earth would look like if it were: a giant potato in space. The model raises areas of the planet where gravity is lower so that the force of gravity is equal across the surface of the colorful, lumpy blob. Gravity varies because the Earth isn’t a perfect sphere and its mass isn’t evenly distributed. The Goce probe, flying lower than any other satellite, measures variations in the gravitational pull—something that will allow it to give a three-dimensional view of what’s happening inside the Earth and shed light on earthquakes.