Jupiter and its Galilean Moons

You can see Jupiter’s moons – Io, Europa, Ganymede and Callisto in the night sky while Jupiter is in opposition; when the planet is opposite the sun in the sky as seen from Earth. When Earth passes directly between Jupiter and the sun, we’ll see Jupiter rise at sunset and set at sunrise. Opposition is the middle of the best time of the year to see a planet, since that’s when the planet is up and viewable all night and is generally closest for the year. But any time Jupiter is visible in your sky you can view Jupiter’s four major moons. Three of the four moons are bigger than Earth’s moon. And one – Ganymede – is the largest moon in the solar system. These four satellites are collectively called the Galilean moons to honor the Italian astronomer Galileo, who discovered them in 1610. September 2022 is a great month to look for Jupiter’s four large moons.

I saw 3 of the moons. The 4th may be in front of Jupiter.

earthsky.org