Disco-ball satellite nails Einstein’s relativity test to 0.2%
A dense, thruster-free satellite named LARES-2, paired with the older LAGEOS, was laser-tracked from Earth to isolate the frame-dragging effect predicted by general relativity. By canceling Earth’s oblateness and tidal perturbations over a 1,050-day cycle, the team measured the Lense-Thirring precession to about 0.2% accuracy, confirming Einstein and narrowing alternatives like Chern-Simons theory, while also delivering a more precise Earth-tide benchmark.
