It's hardly a major prediction but a remarkable one and was amazingly accurate. Just before Voyager arrived at Io, a paper came out that predicted
"The implications of the orbital resonances of the inner three Galilean satellites are profound for the thermal state of lo. These calculations suggest that Io might currently be the most intensely heated terrestrial-type body in the solar system. The surface of the type of body postulated here has not yet been directly observed, and although the morphology of such a surface cannot be predicted in any detail, one might speculate that widespread and recurrent surface volcanism would occur, leading to extensive differentiation and outgassing".
Shortly afterwards Voyager took photographs of Io that showed it to be exactly as described in the paper. It even has active volcanoes..
Wikipedia account here: Volcanology of Io - Discovery
"The implications of the orbital resonances of the inner three Galilean satellites are profound for the thermal state of lo. These calculations suggest that Io might currently be the most intensely heated terrestrial-type body in the solar system. The surface of the type of body postulated here has not yet been directly observed, and although the morphology of such a surface cannot be predicted in any detail, one might speculate that widespread and recurrent surface volcanism would occur, leading to extensive differentiation and outgassing".
Shortly afterwards Voyager took photographs of Io that showed it to be exactly as described in the paper. It even has active volcanoes..
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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