In one minute

Lorenzo Iorio examines the Ciufolini team's test of the Lense-Thirring frame-dragging effect, built on about 3.5 years of laser ranging to the LAGEOS, LAGEOS II and LARES satellites. That test combines the orbital nodes of the three satellites to cancel errors in the first two even zonal harmonics of Earth's gravity field, J2 and J4. Iorio shows that the spread among recent gravity models in the uncancelled zonals of degree 6, 8 and 10 does not yet allow the expected 1% level to be reached unambiguously. For some pairs of models the differences reach 15% for degree 6, 6% for degree 8 and 36% for degree 10.

A comment on 'A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model'