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The Telescope Array project is a collaboration between universities and institutes in Japan, Taiwan, China, Russia, Korea, and the United States. The experiment is designed to observe cosmic-ray-induced air showers at extremely high energies using a combination of ground array and air-fluorescence techniques. It is being deployed in the high desert in Millard County, Utah, USA. We are now in the process of gathering data.

The Telescope Array observes cosmic rays with energies of 10¹⁹ eV and up. The cosmic rays are observed at three fluorescence sites and a separate ground array consisting of 576 detectors.

TALE is the Telescope Array Low Energy extension. It is designed to observe cosmic rays with energies between 3x10¹⁶ eV and 10¹⁹ eV. TALE has two fluorescence sites placed about five kilometers away from TA-1 and TA-2. One of these is at Black Rock Mesa, and the other is at Long Ridge.

Recent News

Solving a Cosmic Ray Conundrum

Astronomers say they have solved a puzzle about the most energetic particles that smash into Earth. Known as ultrahigh-energy cosmic rays, these particles, mostly protons, each pack as much punch as a fast-pitched baseball.

According to a theory first proposed 42 years ago, the particles ought to rarely reach Earth with such high energies because many lose about 20 percent of their energy when they collide with photons from the cosmic microwave background - the Big Bang's afterglow.

Ultrahigh-energy Cosmic Rays Are From Extremely Far Away

Final results from the University of Utah's High-Resolution Fly's Eye cosmic ray observatory show that the most energetic particles in the universe rarely reach Earth at full strength because they come from great distances, so most of them collide with radiation left over from the birth of the universe.

The findings are based on nine years of observations at the now-shuttered observatory on the U.S. Army's Dugway Proving Ground. They confirm a 42-year-old prediction - known as the Greisen-Zatsepin-Kuzmin (GZK) "cutoff," "limit" or "suppression" - about the behavior of ultrahigh-energy cosmic rays, which carry more energy than any other known particle.