Galileo, time and space

The Galileo constellation will be the world's most reliable global navigation system. The technologies that have been developed to achieve such precision will also provide data for use in many other fields, such as oceanography and meteorology. The Galileo system will also open new horizons in fundamental sciences. The extremely small differences in timekeeping between the satellite clocks moving in orbit and their Earth-bound counterparts will lead scientists to a re-evaluation of the nature and influence of gravity in the Universe.ESApod video programme