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!
An example of diffraction, called the 'Bright Spot of Arago' (or 'Poisson's Spot'): a bright point that appears at the center of a circular object's shadow due to diffraction. In 1818, physicist Augustin Fresnel submitted a paper on the theory of diffraction to the French Academy. His proposed light moved a wave, as opposed to a stream of particles. Physicist Siméon Poisson was critical of this theory, arguing that if it were true, a bright spot should appear behind a circular shade, which he thought was obviously untrue. Unfortunately for his argument, physicist Dominique Arago swiftly verified the spot experimentally.