Right on time
An artist's impression of the Cassini spacecraft flying between Jupiter and Saturn, and transmitting radio waves past the Sun and towards the Earth. The radio waves are delayed by their passage through the curved space-time near the Sun, an effect called the Shapiro time delay.
Bruno Bertotti of the University of Pavia in Italy and colleagues have analysed these waves, and their value for the Shapiro time delay agrees with the predictions of general relativity to 1 part in 105.
Credit: NASA