Gamma rays are extremely energetic electro-magnetic waves. Because these rays are blocked by the Earth’s atmosphere they can only be detected from high altitude balloons or by satellites launched into space. Their high energy makes the gamma rays transparent to most of the matter in the universe and enables it to reach us from the furthest corners of the universe. Gamma rays are not deflected by magnetic fields, and therefore, they ‘point back’ directly to their source. Thus, by detecting and studying gamma rays we can actually open a window to the edge of the visible universe.
Due to the elusive nature of gamma rays, the new space observatory has been equipped with two special instruments: the Large Area Telescope (LAT), which detects gamma rays based on Einstein’s famous E=mc2 equation, using a technique called pair production, and the GLAST Burst Monitor (GBM), which is complementary to the LAT and can detect lower energy gamma rays and x-rays. The GLAST has a much wider range and is at least 30 times more sensitive than NASA’s former space observatory, the Compton Gamma-ray Observatory (CGRO), which was operational between 1991 and 2000.
With the ability to “see” the universe through high-energy radiation, NASA’s scientists believe that we will be able to get information about high-energy phenomena that we are currently unable to explain or understand. More specifically, they hope to improve their understanding of particle acceleration in active galactic nuclei, a phenomenon in which matter caught close to a super massive black hole at the center of a galaxy is blown away from the black hole in near light velocities. Another mysterious phenomenon is the Gamma-ray Bursts (GRB), which are unexplained bursts of extreme luminosity from unknown origins. The astronauts would also like to find and study neutron stars, which are created when a massive star gravitationally collapses while retaining very strong gravitational, magnetic, and electric fields.
In addition to the abovementioned missions, the GLAST will be used for research purposes in related fields of science. These missions will include improving our understanding of our solar system and the Milky Way Galaxy, investigating the universe at much earlier times, discovering dark matter and new particles in collaboration with the LHC particle accelerator at CERN, and the testing of fundamental physics by examining the dependence of the speed of light on the light’s wavelength.
The GLAST Project is the product of an international collaboration between France, Germany, Italy, Japan, Sweden, and the U.S. The project is planned to run for five years and will hopefully meet the great expectations of the many scientists who were involved in it. Other than the missions that have already been planned, the main source of hope for most of the GLAST science team members is the prospect of finding something entirely new and unexpected. “This is a relatively unexplored field, so the potential for major discoveries is very high,” says LAT Science Team Member David Thompson of NASA’s Goddard.
TFOT has previously covered a number of discoveries related to the planned GLAST missions, including “black hole’s secrets revealed” – about advancements in the field of active galactic nuclei, and “NASA records huge Gamma Ray explosion” – about a recently detected Gamma Ray explosion. TFOT has previously covered the assembly of the ATLAS detector as part of CERN’s LHC.
More information on the GLAST Project can be found NASA’s website.