The earth wobbles in space... and thanks to global positioning system (GPS) technologies, this wobble has been tracked with a precision of a few millimeters over the last decade... Geoff Blewitt, University of Nevada research geophysicist, has an explanation for this mysterious geo-wobble. "The theory, which my colleagues and I have proven using GPS observations of the Earth, is that it's likely to be caused by the surface matter being redistributed..." To make the Earth wobble, large amounts of mass need to be moved from one place to another so that the Earth is "off balance," according to NASA-funded researcher...