The Pierre Auger Observatory -Status and Prospects -
  The southern Pierre Auger Observatory is presently under construction in Malargue, Mendoza, Argentina. It combines two complementary air shower observation techniques; the detection of particles at ground and the observation of associated fluorescence light generated in the atmosphere above the ground. Experimentally, this is being realised by employing an array of 1600 water Cherenkov detectors, distributed over an area of 3000 km^2, and operating 24 wide-angle Schmidt telescopes, positioned at four sites at the border of the ground array. The Observatory will reach its full size in 2006. However, with the 540 tanks and 12 telescopes presently in operation, the Pierre Auger Observatory has become the largest world-wide cosmic ray experiment already now. This paper sketches the experimental set-up and discusses the current status. In parallel to the ongoing completion of the experiment, a large number of events have been detected with energies above 10^19 eV. The data are used to verify both the performance of the individual detector components as well as to test the quality of the hybrid event reconstruction. All results obtained so far are very promising and they underline the great advantages of the chosen hybrid approach. 
Karl-Heinz Kampert (Pierre Auger Collaboration)