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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This animation shows ESA's Planck observatory scanning the sky and completing its first all-sky survey.
From its orbit around the second Lagrange point (L2) of the Sun-Earth system, Planck performs a continuous scan of the sky. The spacecraft spins at 1 rpm causing the telescope's field-of-view, which is inclined at 85° to the spin axis, to trace out approximate great circles on the celestial sphere. Planck's spin axis is periodically shifted by a few arcminutes per hour in ecliptic longitude (adding up to ~1° per day), to maintain an anti-Sun pointing throughout the year. As a result, the annular region observed with the telescope slowly drifts across the sky, resulting in a complete sky survey.
Version from July 2008.
©ESA - European Space Agency