How does your phone know where you are? How is our planet changing due to geodynamic processes and the ongoing climate change? How can these changes be precisely measured from space to provide reliable information about the melting of ice sheets or the threat to coastal regions from rising sea levels? This non-fiction book answers these socially relevant questions. It is aimed at interested laypeople who want to learn more about our fascinating planet, as well as at experts in scientific disciplines. You will be taken on an exciting journey through time, from the first measurements in antiquity to the age of satellites, which enable us to determine extremely accurate positions worldwide and provide a global view of our home planet. Through illustrative examples, it demonstrates how deeply global positioning and navigation with satellites have permeated our daily lives and what fundamental contributions geodesy, the science of measuring the Earth, makes to understanding the Earth system and assessing the impacts of climate change. Featuring interviews with Günter Hein, Harald Lesch, and Stefan Rahmstorf.