James A. Van Allen Biography

James A. Van Allen Biography You cant see it or feel it, but more than a thousand miles above Earths surface, theres a region of charged particles that protects our atmosphere from destruction by the solar wind and cosmic rays. Its called the Van Allen belt, named for the man who discovered it.   Meet the Belt Man Dr. James A. Van Allen was an astrophysicist best known for his work on the physics of the magnetic field that surrounds our planet. He was particularly interested in its interactions with the solar wind, which is a stream of charged particles flowing from the Sun. (When it slams into our atmosphere, it causes a phenomenon called space weather). His discovery of radiation regions high above Earth followed up on an idea held by other scientists that charged particles could be trapped in the uppermost part of our atmosphere.  Van Allen worked on Explorer 1, the first U.S. artificial satellite to be placed in orbit, and this spacecraft revealed the secrets of Earths magnetosphere. That included the existence of the belts of charged particles that bear his name.   James Van Allen was born in Mount Pleasant, Iowa on September 7, 1914. He attended Iowa Wesleyan College where he received his Bachelor of Science degree. He went on to the University of Iowa and worked on a degree in solid state physics, and took a Ph.D. in nuclear physics in 1939. Wartime Physics Following school, Van Allen accepted employment with the Department of Terrestrial Magnetism at the Carnegie Institution of Washington, where he studied photodisintegration.Thats a process where a high-energy photon (or packet) of light is absorbed by an atomic nucleus. The nucleus then splits to form lighter elements, and releases a neutron, or a proton or an alpha particle. In astronomy, this process occurs inside certain types of supernovae.   In April 1942, Van Allen joined the Applied Physics Laboratory (APL) at Johns Hopkins University where he worked to develop a rugged vacuum tube and did research on proximity fuzes (used in explosives and bombs). Later in 1942, he entered the Navy, serving in the South Pacific Fleet as an assistant gunnery officer to field test and complete operational requirements for the proximity fuzes. Post-War Research   After the war, Van Allen returned to civilian life and worked in high altitude research. He worked at the Applied Physics Laboratory, where he organized and directed a team to conduct high-altitude experiments. They used V-2 rockets captured from the Germans.   In 1951, James Van Allen became head of the physics department at the University of Iowa. A few years later, his  career took an important turn when he and several other American scientists developed proposals for the launch of a scientific satellite. It was to be part of the research program conducted during the International Geophysical Year (IGY) of 1957-1958. From Earth to the Magnetosphere After the success of the Soviet Unions Sputnik 1 launch in 1957, Van Allen ¹s Explorer spacecraft was approved for launch on a Redstone rocket. It flew on January 31, 1958, and returned enormously important scientific data about the radiation belts circling the Earth. Van Allen became a celebrity due to the success of that mission, and he went on to achieve other important scientific projects in space. In one way or another, Van Allen was involved in the first four Explorer probes, the first Pioneers, several Mariner efforts, and an orbiting geophysical observatory. James A. Van Allen retired from the University of Iowa in 1985 to become Carver Professor of Physics, Emeritus, after having served as the head of the Department of Physics and Astronomy from 1951. He died of heart failure at the University of Iowa Hospitals and Clinics in Iowa City on August 9, 2006. In honor of his work, NASA named two radiation belt storm probes after him. The Van Allen Probes were launched in 2012 and have been studying the Van Allen Belts and near-Earth space. Their data is helping the design of spacecraft that can better withstand trips through this high-energy region of Earths magnetosphere.   Edited and revised by Carolyn Collins Petersen