Question

In 1610, Galileo Galilei discovered four moons of which planet?

Answer 1

The Galilean moons are the four largest moons of Jupiter—Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in January 1610, and recognized by him as satellites of Jupiter in March 1610. They were the first objects found to orbit another planet.

Answer 2

$\mathbb{ \ \ ANSWER \: \: }$

In 1610, Galileo Galilei discovered four moons of Jupiter.