Scientists have long speculated that the solid Earth might be expanding or contracting, proposing various theories to back up their contention about one or the other. A NASA study, published in Geophysical Research Letters, has essentially settled the argument.
Using a battery of space measurement tools and a new data calculation technique, researchers detected no statistically significant expansion of the solid Earth, a release by the space agency said Tuesday.
An international group of scientists led by Xiaoping Wu of NASA's Jet Propulsion Laboratory in Pasadena, Calif.-- and including participants from the Institut Geographique National, Champs-sur-Marne in France, and Delft University of Technology in The Netherlands -- set out to evaluate the accuracy of the measurements.
After analysis, they estimated the average change in Earth's radius to be 0.004 inches per year, or about the thickness of a human hair, a rate considered statistically insignificant.
"Our study provides an independent confirmation that the solid Earth is not getting larger at present, within current measurement uncertainties," Wu said.