Exploring the
Auger Observatory
with Google Earth

The Pierre Auger Observatory is a very large array of detectors in Argentina. Its aim is the study of the rarest and most energetic particles in the Universe: cosmic rays (most likely protons or bare atomic nuclei) at extremely high energies, whose origins are still a complete mystery despite decades of intense investigations worldwide. These cosmic rays can be studied indirectly by detecting the billions of high-energy particles they produce in interactions with the Earth’s atmosphere. These come crashing down through the atmosphere in a cascade, or extensive air shower, that can be detected by counters scattered over a wide area, or else at night by detecting with sensitive telescopes the sky glow (nitrogen fluorescence) they produce in traveling through the atmosphere.

Physicists from 15 countries have been deploying detectors over an area of some 3000 km² in western Mendoza province, Argentina, to detect these rare air showers. To this end, some 1600 surface detectors (“water Cherenkov counters”) have been deployed, on a grid with 1.5 km spacing. On hills at the edges of the array, at four different sites, nitrogen fluorescence telescopes are built and operated on dark clear nights, working in coincidence with the ground array. Also near the center of the array are two central laser facilities, used to fire laser shots into the sky at night to calibrate the response of the nitrogen fluorescence detectors. Finally, an observatory campus is located in the town of Malargue, at the edge of the array, with a data acquisition and storage station, office building, and assembly building (where surface detectors are prepared prior to deployment in the field).

Because of the sheer scale of the project, it can be difficult to meaningfully explore the layout of the array and display the various detector components in a way that illustrates the distances involved. To help facilitate this exploration, a model of the Pierre Auger Observatory layout was constructed, to be viewed interactively using Google Earth. This allows the user to display the various detector elements, zoom in on them, tilt and rotate the field of view, etc. Running a Google Earth session requires a computer with reasonably high bandwidth access to the internet. Note that in parts of the map where Google Earth images are available at high resolution, Auger structures are not necessarily visible, depending on whether the Google Earth image (either from a satellite or aerial photo) was taken before or after deployment of the structure.

Please send any comments or questions to Stephane Coutu . All 3D model files (done with the free Google SketchUp tool) are available on request. These models were created with support from the National Science Foundation.

This work is licensed under a Creative Commons Attribution 4.0 International License.