'Potato' Earth's deep secrets By Jonathan Amos BBC News Online science staff It is a map the like of which you have probably never seen before. Gravity highs are marked red; gravity lows are blue The sweep of colours shows minute variations in the Earth's gravitational field. If you were to fly over the red areas, you would be tugged ever so slightly downwards; the blues mark regions where the planet's attraction is much weaker. These gravity anomalies, as they are known, are imperceptible to the human senses, and so the scientists have wrapped the data on to a sphere...
