A confirmation of the general relativistic prediction of the Lense-Thirring effect

An important early prediction of Einstein's general relativity(1-3) was the advance of the perihelion of Mercury's orbit, whose measurement provided one of the classical tests of Einstein's theory(4). The advance of the orbital point-of-closest-approach also applies to a binary pulsar system(5,6) and to an Earth-orbiting satellite(3). General relativity also predicts that the rotation of a body like Earth will drag the local inertial frames of reference around it(3,7), which will affect the orbit of a satellite(8). This Lense-Thirring effect has hitherto not been detected with high accuracy(9), but its detection with an error of about 1 per cent is the main goal of Gravity Probe B-an ongoing space mission using orbiting gyroscopes(10). Here we report a measurement of the Lense-Thirring effect on two Earth satellites: it is 99+/-5 per cent of the value predicted by general relativity; the uncertainty of this measurement includes all known random and systematic errors, but we allow for a total +/-10 per cent uncertainty to include underestimated and unknown sources of error.