1. Galilean moons by: Garrett McWilliams

2. Galilean moons
The names of the moons are from left to right: Callisto, Ganymede, Europa, Io

3. Galilean moons
All of the moons keep one face towards Jupiter, called tidal Locking

4. About Galileo
Galileo Galilei was an Italian scientist. He constructed a telescope with which he studied four moons revolving around Jupiter. We know them as the Galilean Moons.

5. Galilean moons
The four moons are a mixture of rock and ice. The closest to Jupiter is Io, next is Europa, then Ganymede, last is Callisto.

6. Io
Io is a rocky object similar to other planets. It was discovered in Many surface regions of Io are sulfurous in appearance. It is one of the most volcanic surfaces. It is made of sulfur, iron, and other rocky materials. This makes it very unlike the other moons.

7. Europa It is named after a Phoenician princess
Europa It is named after a Phoenician princess. It was discovered in It’s crust is composed of water and ice and has very few craters. Because the icy crust is relatively young, it reflects much of the sun’s light. This causes it to be one of the brightest bodies in the solar system.

8. Ganymede This is the largest of Jupiter’s moons and the largest satellite in the solar system. It was discovered in It is larger in diameter than Mercury. It has many craters and no known atmosphere. It also has an icy surface.

9. Callisto It is about the same size as Mercury
Callisto It is about the same size as Mercury. It has no mountains, because of it’s icy surface. It is the most heavily cratered satellite in the solar system. Its crust is very old, dating back about 4 billion years. Beneath the crust may be a salty ocean about 6 miles thick.