An orbiting disco ball gave Einstein's theory its most precise test yet

An orbiting disco ball gave Einstein's theory its most precise test yet(arstechnica.com)

2 points by lisper 15 hours ago | 1 comment

k310 15 hours ago |

This seems to the referenced paper, paywalled at Nature

Analysis of Tidal Perturbations Due to Asymmetric Response of LARES 2 and LAGEOS (revised 10 Mar 2026) [0]

   Earth tidal perturbations affecting laser-ranged satellites are critical for refining satellite orbital dynamics modeling, and their accurate computation represents a prerequisite for high-precision fundamental physical effects and geodetic investigations based on satellite orbit analysis. This study focuses on the tidal perturbations induced by the asymmetric responses of LARES 2 and LAGEOS on their orbital nodes and inclinations. Perturbations induced by a total of 402 (392 2nd and 10 3rd-order) earth tide constituents on the two satellites were calculated, based on Kaula's orbital perturbation theory and Lagrange's planetary equations for satellites, considering the frequency dependence of Love numbers. The asymmetric characteristics of tidal perturbations between the two satellites were quantitatively analyzed. The minimum resolutions of orbital inclinations and nodes, used as screening thresholds for significant constituents, were derived from the RMS of overlapping orbit differences using orbital geometry and error propagation law. With these thresholds, 83 significant constituents were identified from the 402. The cumulative effect of the 319 minor constituents was further evaluated, and it was found that their total impact, from coherent superposition, noticeably exceeds the thresholds, thus becoming non-negligible. The results of this study provide accurate tidal perturbation parameters for LARES 2 and LAGEOS, and offer methodological references for the screening of Earth tide constituents in high-precision satellite orbital dynamics research, laying a foundation for subsequent studies on inverting geophysical parameters from satellite orbits and verifying fundamental physical effects, particularly the relativistic Lense-Thirring effect.

[0] https://arxiv.org/abs/2603.00685

Earth tidal perturbations affecting laser-ranged satellites are critical for refining satellite orbital dynamics modeling, and their accurate computation represents a prerequisite for high-precision fundamental physical effects and geodetic investigations based on satellite orbit analysis. This study focuses on the tidal perturbations induced by the asymmetric responses of LARES 2 and LAGEOS on their orbital nodes and inclinations. Perturbations induced by a total of 402 (392 2nd and 10 3rd-order) earth tide constituents on the two satellites were calculated, based on Kaula's orbital perturbation theory and Lagrange's planetary equations for satellites, considering the frequency dependence of Love numbers. The asymmetric characteristics of tidal perturbations between the two satellites were quantitatively analyzed. The minimum resolutions of orbital inclinations and nodes, used as screening thresholds for significant constituents, were derived from the RMS of overlapping orbit differences using orbital geometry and error propagation law. With these thresholds, 83 significant constituents were identified from the 402. The cumulative effect of the 319 minor constituents was further evaluated, and it was found that their total impact, from coherent superposition, noticeably exceeds the thresholds, thus becoming non-negligible. The results of this study provide accurate tidal perturbation parameters for LARES 2 and LAGEOS, and offer methodological references for the screening of Earth tide constituents in high-precision satellite orbital dynamics research, laying a foundation for subsequent studies on inverting geophysical parameters from satellite orbits and verifying fundamental physical effects, particularly the relativistic Lense-Thirring effect.