Callisto inogara pamusoro pechando chakatonhora, chakaoma, uye chando chakatonhora chiri pakati pe80 ne150 km mukobvu. Gungwa rine munyu rakadzika 150-200 km rinogona kunge riri pasi peguruva, rinoratidzwa nezvidzidzo zvemagineti akakomberedza Jupiter nemwedzi yayo. Zvakawanikwa kuti Callisto inopindura kumagineti emagineti anoshanduka eJupiter sechinhu chinotungamira zvakakwana; ndiko kuti, munda haugone kupinda mukati meCallisto, zvichiratidza rukoko rwemvura inotungamira mukati mayo nehupamhi hweanenge 10 km. Kuvapo kwegungwa kunonyanya kuitika kana mvura iine huwandu hushoma hweammonia kana imwe antifreeze, inosvika ku5% nehuremu. Muchiitiko ichi rukoko rwemvura + ice rinogona kunge rakakora se250-300 km. Kukundikana kwegungwa, iyo ice lithosphere inogona kunge yakakora zvishoma, kusvika pamakiromita mazana matatu.
250 kusvika ku300 km