A sophisticated satellite has been carefully placed into orbit just beyond the Earth’s atmosphere, and this week engineers switched on the super-sensitive instrument that will make ultra-fine measurements of Earth’s gravity. The sophisticated gradiometer will feel the subtle variations in Earth’s tug as it sweeps around the globe [BBC News].
The GOCE satellite, built by the European Space Agency (ESA), was launched on March 17, and mission controllers are now busy testing instruments and its cutting-edge propulsion system. In August or September, they will begin the scientific mission. Because the Earth’s mass is not distributed evenly around the planet (think of the mountains and the oceanic rifts), its gravity is not uniform. Mapping these variations has many applications but perhaps the biggest knowledge gains will come in the study of ocean behaviour. Understanding better how gravity pulls water – and therefore heat – around the globe will improve computer models that try to forecast climate change [BBC News].
