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
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Global clear-sky UV index 26 March 2001. The UV index is the effective UV-B irradiance (divided by 25 mW/m2) reaching the Earth's surface. This UV index is valid for
clear-sky conditions and will usually be lower for cloudy skies. However, under partially cloudy conditions the UV index can be higher for short time periods. The UV index can be up to a factor 2 higher when the Earth's surface is covered with snow.
(image courtesy KNMI/ESA)