New Twists in Earth's Radiation Belts

摘要

Late in the evening of January 31, 1958, a 32-ton Juno I rocket blasted into space from Cape Canaveral, Florida, lofting tike Explorer I spacecraft into orbit. It was a mission of firsts: Explorer I was the first American satellite (joining Sputnik 2, which had been launched the previous November by the Soviet Union). The satellite carried a pioneering scientific payload, prepared at the State University of Iowa by a team of researchers led by James A. Van Allen. And the instruments on Explorer I made the first revolutionary discovery of the Space Age: Earth is enshrouded in doughnut-shaped rings, or toroids, of high-energy, high-intensity radiation.