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GLAST = Fermi

Published on Sep 2, 2008 at 4:42 pm. 1 Comment.
Filed under space telescopes.

Several months ago, I wrote about NASA’s plans to rename GLAST (the Gamma Ray Large Area Space Telescope). Last week, NASA announced that the new name for this mission is to be the Fermi Gamma-ray Space Telescope. Enrico Fermi was an Italian physicist who became well known in the 1920s and 1930s for his work in subatomic particles. In fact, an entire class of particles is called “fermions” in his honor. A lot of people have heard about fermions, whether the name is used or not. No two fermions able to interact with one another can occupy the same energy state. This is a statement of the famous Pauli Exclusion Principle, and is the reason for the filling order of the energy levels in atoms, because electrons are fermions. Fermi’s interests then focussed on nuclear physics. Fermi won the Nobel Prize in physics in 1938. He immigrated to the United States prior to World War II and even worked on the Manhattan Project to create the atomic bomb. Fermi became an American citizen in 1944. His latter years were focussed on studies of high energy astrophysics, attempting to explain the very high energies associated with cosmic rays. It is for this work that he is honored by the renaming of GLAST to be the Fermi Gamma-ray Space Telescope.

The Fermi telescope seems to be operating just fine. It has already produced its first all-sky survey image, seen above. Gamma rays do not penetrate through the Earth’s atmosphere, so astronomers must launch telescopes outside of the atmosphere to study them. That is what GLAST (now Fermi) is designed to do. Some of the most energetic events in the universe produce gamma rays, and instruments such as those carried by Fermi are what we need to study these events. Fermi is not the first space telescope dedicated to gamma rays. There have been others, including the Compton Gamma Ray Observatory (CGRO). The CGRO took several years to produce an all-sky image not nearly as good as the one shown here. With Fermi’s advanced capabilities, we should expect to be hearing about all sorts of new discoveries over the life of the craft.

-Astroprof

Images courtesy NASA