1. Maddie Barrett, Rachel Bell, and Rachel Bibb
Galilean Moons
Maddie Barrett, Rachel Bell, and Rachel Bibb

2. Size Galilean moons have a diameter of more than 200 meters.
Galilean moons are the four largest moons orbiting Jupiter.
Three of the Galilean moons are bigger than Earth’s moon and one moon are smaller than Earth’s moon.

3. General Color and Unique Surface Features
Surface is yellow-red Scientists think that the volcanic materials are sulfur and sulfur dioxide.

4. How Long is a Day and a Year?
Io- Rotates in 42 hours (About 1 ¾ days on Earth) Europa- Rotates in 85 hours (About 3 ½ days on Earth) Ganymede- Rotates in hours (About 7.15 days on Earth) Callisto- Rotates in hours (About 16.7 days on Earth) Io- Revolves around Jupiter in 42 ½ hours (About 1 ¾ days on Earth) Europa- Revolves around Jupiter in 85 hours (About 3 ½ days on Earth) Ganymede- Revolves around Jupiter in hours (About 1 week on Earth) Callisto- Revolves around Jupiter in 396 hours (About 16.5 days on Earth)

5. Density
Density decreases as distance from Jupiter increases. Io g/cc ~ less dense than earth’s moon Europa g/cc ~less dense than earth’s moon Ganymede g/cc ~less dense than earth’s moon Callisto g/cc ~less dense than earth’s moon

6. Gravity
Io-1.8 m/s² Europa m/s² Ganymede m/s² Callisto-1.24 m/s²

7. Atmosphere Composition
Io has an atmosphere consisting mainly of sulfur dioxide. Europa has an atmosphere composed mostly of molecular oxygen. Ganymede has an atmosphere with oxygen atmosphere. Callisto has an atmosphere containing carbon dioxide.

8. Surface Composition
Io has a surface composition of volcanic material. Europa has a surface composition with a 100km sheet of ice containing cracks and what is thought to be liquid water under it. Ganymede has a surface containing various ridges and valleys. Callisto has a surface that is densely cratered and possibly the most densely cratered in our solar system.

9. Interior Composition
Io has an Iron sulfide core, outer silicate crust and partially silicate mantle. Europa has a solid ice crust, silicate mantle and a metallic core Ganymede has a cold ridged ice crust, outer warm ice mantle, inner silicate mantle, and metallic core. Callisto has a surface of ice layer, possible liquid layer, and ice rock interior.

10. Magnetic Fields
Io has a strong magnetic field. Europa has a magnetic field similar to Io. Ganymede has a weak magnetic field. Callisto has a very weak magnetic field.

11. Unique Features
Io has tidal forces from the other moons cause Io’s surface to move in and out 100m. Europa has what is thought to be good conditions for extraterrestrial life. Ganymede is the largest moon in moon in the solar system. Callisto may be one of the most densely cratered moons in our solar system.

12. Summary
size
Io, Ganymede, Europa are larger than our moon but Callisto is smaller than our moon.
color and feature
The colors of the moons are yellow red and Io contain sulfur, sulfur dioxide and volcanic materials
day and year
Their days are between 1-16 day of earth. their years are about 1-16 days of year as well
density
The Galilean moons are less dense than Earth’s moon.
gravity
Io-1.8 m/s² ~ Europa m/s² ~ Ganymede m/s² ~ Callisto-1.24 m/s²
atmosphere composition
Io has sulfur dioxide. Europa has molecular oxygen. Ganymede has oxygen atmosphere. Callisto gas carbon dioxide.
surface composition
Io has volcanic material. Europa has 100m sheet of ice and water is under the ice. Callisto has craters.
interior composition
Io has an iron sulfide core. Europa has a metallic core. Ganymede has a metallic core. Callisto has a ice rock core.
magnetic field
Io has a strong magnetic field.
Europa has a magnetic field similar to Io.
Ganymede has a weak magnetic field.
Callisto has a very weak magnetic field.
unique features
Io- tidal forces from the other moons cause Io’s surface to move in and out 100m. Europa- has what is thought to be good conditions for extraterrestrial life. Ganymede- is the largest moon in moon in the solar system. Callisto may be one of the most densely cratered moons in our solar system.