Shi ne mafi na ciki na Galilean tauraron dan adam na Jupiter, da orbit kwance a tsakanin wadanda na Thebe da kuma Turai. Ciki har da Jupiter ta ciki tauraron dan adam, Io ne na biyar watã daga Jupiter. Yana daukan game da 42.5 hours don kammala daya orbit a kusa da Jupiter (sauri isa ga motsi da za a lura a kan guda dare na kallo). Io ne a cikin wani 2: 1 talakawan-motsi orbital resonance da Europa da kuma wani 4: 1 talakawan-motsi orbital resonance da Ganymede, kammala biyu orbits na Jupiter ga kowane daya orbit kammala ta hanyar Turai, da kuma hudu orbits ga kowane daya kammala ta hanyar Ganymede. Wannan resonance taimaka Io ta orbital eccentric watã (0.0041), wanda ya samar da farko juyawa aiki domin Jupiter.
42.5 sa'a daya