Directions: Select the correct text in the passage. Which sentence best states the central idea of the passage?

7. Many Moons

Jupiter is the most massive planet in our solar system and has an enormous magnetic field.
With four large moons and many smaller moons, Jupiter forms a kind of miniature solar system.
Newly discovered moons of Jupiter are reported by astronomers and acknowledged with a
temporary designation by the International Astronomical Union. Once their orbits are confirmed.
they are included in Jupiter's large moon count. Not including the "temporary" moons, Jupiter has 53 totall
Jupiter's four largest moons-lo, Europa, Ganymede, and Callisto-were first observed by the
astronomer Galileo Galilei in 1610 using an early version of the telescope. These four moons are
known today as the Gailean satellites Galileo would be astonished at what we have learned
about these moons, largely from the NASA mission named for him: lo is the most volcanically
active body in the solar system, Ganymede is the largest moon in the solar system and the only
moon known to have its own magnetic field; and a liquid-water ocean with the ingredients for fe
may lle beneath the frozen crust of Europa, making it a tempting place to explore.