The Pamplona Planetarium hosted the Spain National Node for the international project named VT-2004, a whole compendium of activities of science popularisation based on the Venus Transit of June 8, 2004, including an on-line calculation of the Astronomical Unit using the transit observation method depicted by Edmond Halley in 17th Century. To achieve a wide knowledge of the activities, and to encourage citizens to participate in, several different networks (mainly using the Internet) were established that coordinated the participation of different institutions and individuals: planetariums and science centres; research institutions, observatories and universities; colleges and schools; amateur astronomer associations and groups; other cultural associations and the media. A wide range of activities were promoted throughout the nation, all of them having thus a common coordination centre. Acceptance from the society was achieved, with a wide coverage of media and great participation of people in all the activities.