780 million km from the Sun (5 times the distance of the Earth from the Sun)
12 Earth years
140,000 km (11 times the diameter of the Earth)
9.9 Earth hours
320 times the mass of the Earth
(The diameter of Io is 3,600 km, Europa is 3,100 km, Ganymede is 5,300 km and Callisto is 4,800 km. These compare with the diameter of the Moon, which is 3,500 km.)
In terms of mass, Ganymede is about double the mass of the Moon. Both Io and Callisto also have a greater mass than the Moon, but Europa has a smaller mass, despite being larger in volume.