I will discuss frequency standards that measure changes to 1 part in 10^19 and their potential in space and on Earth. On Earth, the slow down of time due to changes in the water table, magma that reaches the upper crust or the presence of lighter material like oil affects the tick rate of ultraprecise atomic clocks.

Satellite tracking involves sending light signals to Earth. Both the orbit of the spacecraft and the electromagnetic signals are affected by spacetime curvature. The arrival times of the pulses can be compared to the ticks of local clocks to reconstruct the orbital path of the satellite to high accuracy. In this talk I will discuss the size of higher order general relativistic effects like frame dragging for space missions on highly eccentric orbits like Juno and Cassini and the effect of the planet’s spin on the satellite orbit.

The ultimate goal is to learn to use general relativity as a tool that teaches us about spacetime and the objects that curve it instead of modification of newtonian physics that has to be corrected for.