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!
Atoms resonate at extremely consistent frequencies. Atomic clocks work by measuring the electromagnetic signal emitted by excited atoms and using this as a timekeeping standard – they are the most accurate clocks known. Pictured are the two active hydrogen masers located in a basement at ESA's ESOC operation's centre, installed in a dedicated temperature and humidity-controlled maser room. Masers produce 'coherent' electromagnetic waves and are used as the timekeeping device in atomic clocks.
Since November 2021, ESA’s satellites and ground stations have been running on a newly defined, incredibly precise “ESOC time”. Measured by these two atomic clocks, the new time determination will bring wide-reaching operational benefits for all ESA missions, making new feats possible in space while adding to our global definition of ‘now’.