Description:
The Gravity Recovery And Climate Experiment Follow-On (GRACE-FO) mission will map variations in Earth’s gravitational field. GRACE-FO is a successor to the original GRACE mission, which began orbiting Earth on March 17, 2002. Unlike other missions, the GRACE satellites together form the “instrument”: Two identical spacecraft, orbiting Earth at about 220 km (137 mi) apart, will constantly send signals to each other to measure and track how the distance between them changes as gravity pulls on each satellite. This lenticular card illustrates the movements of the satellites as they pass southward from the Caribbean Sea across Colombia and Peru (i.e., a denser landmass) to the Pacific Ocean.