The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
Go to topicThank you for liking
You have already liked this page, you can only like it once!
An Earth-orbiting radar cannot see the ocean floor, but it can measure ocean-surface height variations induced by the topography of the ocean floor. The gravitational pull of the seafloor produces minor variations in ocean surface height. Seafloor mapping by ships is much more accurate than radar altimeter mapping, but to date only 10% of the seafloor has been charted this way. A complete mapping of the deep oceans using ships would take 200 ships navigating Earth, 24 hours a day, for an entire year at a cost of billions of dollars. Mapping using satellite radars can cover a larger area in a shorter amount of time. When interesting features are discovered in satellite measurements, they can later be surveyed in fine detail by ships.