Geodesy is the science of measuring and understanding the shape and size of Earth. It helps us to measure the exact positions of features on the surface of the Earth and to find out how the shape of Earth changes over time. It also helps us monitor sea level change, track the movements of tectonic plates, predict floods and droughts, and study the effects of climate change. This science is important for a number of different industries, such as mapping, civil engineering, urban planning, and a variety of other areas.