As fate wants it, most of the roman gods are the greek gods they adapted before and after conquering them. They don't call one moon Zeus, because the planet Jupiter already exists. They don't use the same good in two languages.
Even if they did, it still can't account for all 145 planetoids of our solar system.
Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas, Hyperion, Prometheus, Pandora, Phoebe, Janus, Epimetheus, Helene, Telesto, Calypso, Atlas, Pan, Ymir, Paaliaq, Siarnaq, Tarvos, Kiviuq, Ijiraq, Thrym, Skadi, Mundilfari, Erriapo, Albiorix, Suttung...
to name some Jupiter moons. They are in many parts from greek mythology like Calypso, Pandora or the Titans Atlas and Prometheus... or from Nord mythologie like Ymir... so yes they are religious or fantastic. In the end they are not one mythology though.
One Thread To Guide Them All
"Nothing incorporeal wields such power as a word. Though it is the weapon of the smart and cunning it alas needs the same to prevail."