If, at first, human being used stars to find its bearings, mankind can nowadays count on science to measure the Earth at a millimetric scale. Because land surveying of our planet is still in full swing. Satellites, cameras or drones : technology progress allows the scientists to explore it all. They can measure oceans, volcanoes, or even the atmosphere. But scientists are walking a tightrope, torned between their desire to gather more and more informations, and a population concerned about personal data's protection. This documentary shows a glimpse of actual scientifical research, and interrogate numerous scientists about the interest of land surveying in their specific field of research.