Testing Gravity On Solar System Scales

Newtonian gravity is an extremely well-tested theory on human scales. However, alternative theories attempting to explain dark matter or dark energy predict that there might be small deviations, on large spatial scales, from the classical 1/R² dependence of the gravitational force. NASA’s Pioneer 10 and 11 spacecraft flew beyond Jupiter and provided a means of characterizing gravity on planetary scales, but those measurements suffered from uncertainties due to the difficulty of accounting for drag caused by various instrumental effects. Now, researchers at Stanford University, California, have proposed an optimized space mission to measure modifications to Newtonian gravity on Solar System scales.