The Pierre Auger Observatory is designed to study the highest energy cosmic rays with unprecedented statistics and precision. To celebrate the imminent completion of the construction of the southern site, along with the presentation of the first science results in the summer of 2005, we celebrated a ceremonial event at the Observatory, in Malargüe, Province of Mendoza, Argentina in November 2005. We were especially pleased to mark our scientific launch during the World Year of Physics.

There was an informal reception on the evening of 9 November, followed by formal celebratory activities on 10 and 11 November. A symposium on Thursday, 10 November included presentations on the origins of the project, the construction, and the first science results. Guided tours of the Observatory were given on 11 November. We concluded on Saturday, 12 November, with a science fair featuring participants from local schools.

Distinguished guests from many of the countries participating in the Auger Collaboration attended the celebration. Although our site is off the beaten path, the experience of seeing this unique project, attending its celebration, and exploring the area was a memorable one and well worth the long journey. You will find links to the official program and photos of the celebration in the left-hand column of this page.

The Observatory collaboration includes more than 370 scientists and engineers from 60 institutions in 16 countries, and the construction cost of approximately $50 million (US) has been shared by the participating countries. The Pierre Auger Cosmic Ray Observatory is named for French scientist Pierre Victor Auger (1899-1993), who in 1938 was the first to observe the extensive air showers generated by the interaction of very-high-energy cosmic rays with the earth’s atmosphere.