While some of the energetic beta particles followed the Earth's magnetic field and illuminated the sky, other high-energy electrons became trapped and formed radiation belts around the earth. There was much uncertainty and debate[by whom?] about the composition, magnitude and potential adverse effects from this trapped radiation after the detonation. The weaponeers became quite worried when three satellites in low Earth orbit were disabled. The half-life of the energetic electrons was only a few days. At the time it was not known that solar and cosmic particle fluxes varied by a factor 10, and energies could exceed 1 MeV. These man-made radiation belts eventually crippled a third of all satellites in low Earth orbit. Seven satellites failed over the months following the test, as radiation damaged their solar arrays or electronics, including the first commercial relay communication satellite, Telstar, as well as the United Kingdom's first satellite, Ariel 1. Detectors on Telstar, TRAAC, Injun, and Ariel 1 were used to measure distribution of the radiation produced by the tests.
In 1963, it was reported that Starfish Prime had created a belt of MeV electrons. In 1968, it was reported that some Starfish electrons had remained for five years