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
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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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Variations in the X-ray brightness of the active black hole at the core of distant galaxy GSN 069, about 250 million light years away, as recorded by ESA’s XMM-Newton X-ray observatory (blue) and NASA’s Chandra X-ray observatory (red). The graph shows the X-ray brightness of the source relative to its ‘dormant’ level.
This source was first observed to undergo before-seen flashes on 24 December 2018, when its brightness suddenly increased by up to a factor 100, then dimmed back to its normal levels within one hour and lit up again nine hours later. Further observations performed over a period of 54 days confirmed this flaring behaviour, with ‘quasi-periodic eruptions’, or QPEs detected every nine hours.
Although never before observed, scientists think periodic flares like these might actually be quite common in the Universe.