This booklet provides a clear introduction to Earth observation with the European Copernicus programme. It introduces the Sentinel satellites – the “Sentinels in Space” – and their tasks in observing the climate, environment and changes on Earth. In addition to technical basics such as resolution, spectra and image interpretation, the booklet shows practical examples of how satellite images can be used in school lessons – for example, in geography, biology, physics or computer science. It also explains current educational projects, freely available data portals and software tools such as SNAP. The booklet thus provides valuable ideas on how satellite data can be used in the classroom to promote media literacy, critical thinking and practical learning.