Visit to Pierre Auger`s Observatory

Pierre Auger Observatory, located in the City of Malargüe, searches for the origin of the so-called “cosmic rays” in order to take another step towards the understanding of the universe. The tourists who visit this city have the opportunity to go on an amusing tour around the observatory to find out what this important project, which involves the participation of 17 countries take part and approximately 350 scientists, is about.

This undertaking is the largest in its kind as there are cosmic ray detectors spread all over a 3,000-square-kilometer surface in the fields surrounding the city so as to carry out an analysis of these strange particles that reach our planet. These particles are monitored and later analyzed in a building located in Malargüe.

The history of cosmic rays research is a romantic scientific adventure tale. During three quarters of a century, researchers of cosmic rays have climbed mountains, hovered in hot air balloons and traveled to the most remote confines of the planet in their quest to understand these particles that move fast around space.

The Pierre Auger project continues with this tradition, as it searches for the unknown source of cosmic rays featuring the highest energy to be recorded so far.
The reason for the location of the observatory in Malargüe is not accidental. The pure air of the mountain range, a plain 3,000-square-kilometer surface standing between the 1,200 and 1,400 m.a.s.l. and the 35º South latitude where it lies were determinant factors.

At present, a twin observatory is being built in the Northern hemisphere (more precisely at Lamar, Colorado, United States) so as to cover the entire surface of the sky and detect the rays.
Each site will have a network of 1,600 detectors, separated by a distance of 1.5 kilometers and covering a total surface of 3,000 square kilometers. The network of surface detectors will be completed with a set of high-sensibility telescopes that will examine the atmosphere on cloudless nights to observe the faint ultraviolet light produced by the rain of cosmic rays as it crosses the air. Pierre Auger Observatory is totally completed in such sense.

As a result of this development, particle astronomy studies have been carried out for the first time.
Here we present a question guide provided by the observatory to respond some of the most usual interrogations and to raise some others. When visiting Malargüe, do not miss a tour around the Pierre Auger Observatory, a real international experiment for the study of cosmos and its highest energies. Here is an invitation.


What are cosmic rays?
Cosmic rays are particles coming from outer space and bombarding the Earth constantly and in all directions. Most of these particles are electron or atom nuclei. Some of them are more energetic than any other particle observed in nature. Ultra-energy cosmic rays travel at a rate very close to the speed of light and include hundreds of millions of times more energy than the particles produced by any accelerator in the world.


Where do the Ultra- energy cosmic rays come from?
No one knows what the sources of the ultra- energy cosmic rays are. Most of the particles of low energy cosmic rays reaching the Earth come from some corner of our galaxy, the Milky Way. Many of them come from the explosion of stars known as supernovas. Nevertheless, most ultra- energy cosmic ray particles may come from sources beyond the Milky Way. No source is known to produce particles with these levels of energies in the cosmos, not even in the most violent star explosions.

The origin of high energy particles keeps secrets regarding the evolution and possible origin of the universe due to the mystery of their enormous amount of energy, millions of times more powerful than any earthly accelerator of particles may produce.


How can the ultra-energy cosmic rays be studied?
Cosmic rays may be detected indirectly on the surface of Earth by observing cascades of particles produced in the air. A cascade occurs when a high-speed particle crashes into other air molecules in the rain that continues until the energy of the original particle has been distributed among millions of particles falling over the Earth.
It is by measuring these cascades that the properties of the original cosmic ray or particle may be studied by the scientists.


Pierre Auger Observatory
In order to solve the ultra- energy cosmic rays mystery, the Pierre Auger Observatory will measure the particle cascades created every time a cosmic ray crashes into the molecules of the upper atmosphere. That is how the energy, the direction and the nature of the cosmic rays featuring the highest observable energies will be determined.

Source: www.auger.org.ar and observatory guides.