Detecting cosmic rays on the Earth's surface is more difficult because of scattering interference caused by the atmosphere. Dedicated observatories, which run science projects studying cosmic rays, are located in several places around the world. An example of a current project is the detection of ultra-high energy neutrino flux at the Mixed Apparatus for Radar Investigation of Atmospheric Cosmic-Rays of High Ionization (MARIACHI) observatory in Stony Brook, New York. Many universities, such as Cal Tech, run projects, such as the California High School Cosmic Ray Observatory (CHICOS) which align with local high schools to provide scientific research experience to interested students.
Cosmic rays were the center of science projects conducted by satellites since Explorer 1 was launched in 1958. Modern satellites include the Spaceship Earth detector and NASA's Advanced Composition Explorer (ACE). The primary project of these satellites is to determine the role cosmic rays play in space weather phenomenon. Detectors on modern satellites are sensitive enough to detect the isotope composition of galactic cosmic rays that originate outside our solar system.
The first science project involving cosmic rays was performed on a balloon by Victor Hess in 1912. He determined that the origin of cosmic rays was from outer space, ruling out the theory that they came from the center of the Earth. Modern balloon-borne projects include the BOOMERanG experiment, which measured cosmic ray background radiation in large parts of the sky. The data measured allowed astronomers to see clearer pictures of the universe at an early stage of development.
There are many high school science projects on cosmic rays which can be conducted with the right equipment. Detection of cosmic rays is straightforward with a Geiger counter. As cosmic rays bombard the Earth constantly, they can be measured at any time as a background radiation source. More sophisticated projects make use of scintillators arranged in an ordered array which allow students to visualize the directional origin of the cosmic rays.