In a major new confirmation of Einstein’s Theory of Relativity, the LARES-2 (Laser Relativity Satellite 2) has measured frame dragging around Earth with unprecedented precision.
Ignazio Ciufolini of China’s Wuhan Institute of Physics and Mathematics led the team behind a new paper published in Nature reporting the most precise measurement of the effect to date. The researchers reduced the uncertainty to just 0.2 percent, compared with several percent—and in some cases as much as 10 percent—in previous measurements.
Also known as the Lense-Thirring effect, named for the physicists who modeled it in 1918, frame dragging is the pull of a rotating mass on spacetime. The phenomenon was first predicted in Einstein’s Theory of Relativity.
Seeking Frame Dragging
Frame dragging becomes more pronounced around faster-spinning and more massive objects. For this reason, its effects are far stronger around black holes than around comparatively small bodies such as Earth. Some black holes possess millions or even billions of times the Sun’s mass, producing an immense distortion of the surrounding spacetime.
LARES-2, a satellite developed by the Italian Space Agency, made the new measurement possible. Its appearance has been compared to a golf ball or a disco ball, with its 303 corner-cube retroreflectors creating golf-ball-like divots on its surface, which is composed of a nickel-chromium alloy called Inconel 718.
The spacecraft is remarkably simple, with no thrusters, solar panels, or onboard electronics cluttering its compact, 16-inch-wide frame. Despite its small size, LARES-2 weighs roughly 650 pounds. This combination gives it the lowest area-to-mass ratio of any satellite in medium Earth orbit, minimizing the influence of nongravitational forces on its motion.
Measuring Frame Dragging
The effect of gravitation on the object was then measured by bombarding it with ground-based lasers, which the retroreflectors bounce back to the surface. Ciufolini’s team collected roughly 200,000 of these observations between July 2022 and June 2025, with one-millimeter precision, forming the dataset from which they calculated the frame-dragging effect.
The method presents a significant challenge, however. Earth is an oblate spheroid, with bulging sides created by centrifugal force, rather than a perfect sphere, which produces Newtonian forces that interfere with the frame-dragging signal. To mitigate this issue, the researchers used another satellite in a supplementary orbit, canceling out the effect of the opposing Newtonian forces.
That second satellite was NASA’s LAGEOS, launched in 1976. The orbital planes of LAGEOS and LARES-2 differ by 180.01 degrees—remarkably close to the ideal separation of 180 degrees.
A Final Challenge
One additional complication remained: the K1 lunisolar tide, a variation in Earth’s gravitational field produced by the combined influence of the Moon and Sun. Time provided the solution. Over the tide’s 1,050-day precession cycle, its effects average out and can be removed from the data.
After accounting for these sources of interference, the researchers measured a drift of 61.3 milliarcseconds per year in the satellites’ orbits caused by Earth’s frame dragging. The result closely matches the value predicted by general relativity, with only a narrow margin of uncertainty.
The researchers say the true value of their finding lies not just in confirming general relativity, but also in limiting the scope of the Chern-Simons theory, which seeks to reconcile general relativity with quantum mechanics for a Theory of Everything. Of more limited concern, the work also provided the most precise K1 tide measurement ever recorded, which could prove important to future Earth science research.
The paper, “LARES-2 Satellite Measures Frame-Dragging Effect Around the Earth,” appeared in Nature on July 8, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.