Sept. 7, 1914: The birth of James Van Allen

Today in the history of astronomy, the discoverer and namesake of Earth’s radiation belts is born. | Published: September 7, 2026 The two radiation belts circling Earth are named for the man who found and researched them: James Van Allen. Credit: NASA James Van Allen, who was born in Iowa on Sept. 7, 1914, showed talent and interest in science and math from an early age. A major in physics from Wesleyan College in 1935 was followed by a Ph.D. in nuclear physics in 1939. Before and after World War II – during which he developed antiaircraft radio technology for the Navy – Van Allen worked in the Applied Physics Lab of Johns Hopkins University, and in 1951, became head of the Department of Physics at the University of Iowa. On Jan. 31, 1958, when the Explorer 1 satellite launched, it carried a Geiger counter and cosmic ray experiment designed by Van Allen. The data returned by Explorer 1 and subsequent orbiters led to Van Allen’s discovery of the radiation belts around Earth, two donuts of charged particles trapped by our planet’s magnetic field. The particles of the outer belt come from the Sun, while the inner belt is created by cosmic rays interacting with our atmosphere. As the radiation could severely damage spacecraft – not to mention be hazardous to astronauts’ health – Van Allen’s discovery and his further research into the Van Allen Radiation Belts was a key step in safe space exploration. He passed away in 2006 at the age of 91. Elisa Neckar is senior production editor of Astronomy magazine, and the editor of the Today in the History of Astronomy feature on Astronomy.com.