The BBC has an article on the European Space Agency’s GOCE satellite being used to map the variations in gravity. What! You thought that gravity was just 9.8 meters/sec²? That was the value we used in all of our engineering classes (unless we had to use English units and use 32.2 ft/sec²). Actually, gravity varies from 9.78 meters/sec² at the equator to 9.83 meters/sec² at the poles. (The newest weight loss regimen will be to move to one of the dark blue areas, I suppose.)
One other item makes this map interesting. Take a look at the sinusoidal orange-colored marks across the world. These marks are best seen over the Pacific Ocean. Those sinusoidal marks are the track of the satellite as it orbits the earth. This is because GOCE has only been in operation for only 47 days, which means that not areas of the earth are covered equally. Thus, this data is preliminary, but still cool.
