10 April

1995: On 10 April 1995, the Russian Deputy Minister for Foreign Affairs Georgij Enverovich Mamedov and ESA's Director General Jean-Marie Luton, at the Ministry of Foreign Affairs in Moscow, signed an agreement between the Russian Government and ESA concerning the establishment of an ESA Permanent Mission in Russia.

ESA opened its Permanent Mission in Moscow, headed by Mr Alain Fournier-Sicre, to facilitate its co-operation, with the Russian Agency in particular, across a wide range of science and technology.

1961: On 10 April 1961, scientists performed radar tracking of the planet Venus for a total of seven weeks. This proved that the 'astronomical yardstick' of 150 438 483 kilometres (93 498 125 miles), the average distance between the Earth and Sun, was true.

This distance has become the standard measure of distance within the Solar System, the Astronomical Unit (AU).