Space activities are not just observing space, but also observe the Earth from space. Terrestrial monitoring has a wide range of applications ranging from environmental and climate issues to geopolitical and military ones. On the occasion of the 2025 Ministerial Council of the European space agency we had the opportunity to talk about it with Simonetta Cheliresponsible for ESA’s terrestrial monitoring programmes. One thing that few people know is that Europe is a leader in this sector, mainly thanks to satellites Sentinel within the European program Copernicus.
Why is it important to observe the Earth from above and what applications does terrestrial monitoring have?
It is important to observe the Earth from above because we need to know the state of health of our planet and understand which indicators best help us manage the environment, sustainability on land and liveability on land. It is essential to have information data, for example on the quality of the air we breathe. We have satellites that measure air quality every hour, not every day. It is essential to observe the Earth also to have a better understanding of the evolution of forests, the melting of glaciers, the rise in sea levels, but also to better manage city planning and many aspects of daily life: from weather forecasts to activities such as fishing which require knowing the sea temperature.
Europe boasts the operation of Sentinel satellites, which are among the most advanced in the world for earth monitoring. What do they observe and for what purposes are they used?
The Sentinel satellites are the space component, managed by ESA, of the European Copernicus program developed by the European Union. The Sentinel project has been going on for 27 years and the first “sentinel” was launched in 2014 and was a radar satellite. In early November we launched the fourth of this family of radar satellites, also made by an Italian company. This satellite is also equipped with a tool called Automated Identification Service which allows it to automatically identify vessels. It is essential, for example, to identify illicit trafficking by sea and should join the radar that monitors marine pollution. With these satellites we can also monitor the evolution of ice, deforestation, everything related to land subsidence and help us organize scientific work on earthquake prediction.
The latest ESA Ministerial confirmed that Europe is focusing heavily on Earth observation, which represents one of the most important budget items for the European space agency. What can we expect for the future?
The confirmation of the Member Countries at the Ministerial was important, not only as political support for the priority on issues such as environment, climate, resilience and security, but also for the programmatic and financial priority. In fact, the investments are substantial in terms of continuity of existing programs, such as Copernicus, but also in terms of the development of new scientific missions which also have value as support for the commercial perspective of companies, which in a sector such as Earth observation is fundamental. Then there is a new initiative on resilience and security: we are in fact observing an increase in extreme events linked to natural disasters and catastrophes, unfortunately, and for this reason there is a greater need in terms of data, missions and number of satellites. Europe and ESA will also work on this in the coming years.
