Citizen science is about the support of work on scientific projects by interested citizens. Internet-based cooperation platforms offer the appropriate infrastructure for this purpose. In terms of content, topics from the specialist departments are picked up and implemented with the participation of the public. For example, data collected by citizens on soil moisture or the condition of vegetation in their local environment could be used to calibrate satellite-based earth observation data. The first such proposals date back to the 1990s (Global Learning and Observations to Benefit the Environment GLOBE).