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 topicThe left picture shows a photo of the quasar, taken by XMM-Newton. The dip in the spectrum of the quasar APM 08279+5255 is caused by the element iron. In a same way that our bones appear dark in X-ray photographs because they are opaque to X-rays, the outflowing iron clouds of APM 08279+5255 are opaque for X-rays that are created at the quasar's centre. At the 'absorption energy' characteristic for iron (marked by the red arrow), some part of the X-ray light is missing.