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 topicOur planet is surrounded by a magnetic shield - the magnetosphere - which protects the Earth from most of the charged particles that are blasted across interplanetary space by explosions of the Sun.
In this image, the four Cluster spacecraft are flying in tetrahedral formation in the vicinity of the magnetopause - the outer boundary of the magnetosphere. Here, one spacecraft (right) is still inside the magnetic field, one (centre) is at the undulating magnetopause and the other two have passed into interplanetary space.
Events such as this will take place on a regular basis over the next two years. By comparing data from each member of the Cluster quartet, scientists are gathering the first detailed, three-dimensional views of the most important regions in the magnetosphere.
See also an animation illustrating how the four Cluster spacecraft can measure different parts of the waves as they move through the magnetopause.