From their perch in Earth's orbit, a pair of Sentinel-1 satellites zip from pole to pole, constantly snapping pictures of our changing world — day or night, day after day, regardless of the weather — using their Synthetic Aperture Radar capable of penetrating clouds and darkness to make highly detailed images down to 15 feet. A pair of sister satellites, Sentinel-2, are hot on their heels, capturing high-resolution, optical images to monitor global soil and water coverage, among other things. These roving eyes in the sky are just a few of the satellites that make up the Copernicus joint initiative between the European Commission and the European Space Agency to provide real-time information on the environment and global security. The data they collect is continuously beamed back to Earth, where it is archived and made publicly available to scientists, researchers and developers using Copernicus Open Access Hub and Google Earth Engine.