Ganymede, a satellite of the planet Jupiter. With a diameter of 3,270 miles (5,260 km), Ganymede is the largest satellite in the solar system, and is larger than the planet Mercury. Its surface is composed of ice and has distinct dark and light areas. The dark areas are heavily cratered and the light areas are covered by long, parallel channels. Ganymede was discovered by Galileo Galilei in 1610.
Scientists have discovered the existence of water on both our moon and on Mars. Both findings are significant, but what do they mean? Can we use this information to our advantage for space exploration?
Long, long ago, our sun began its life as a mere twinkle in the universe's eye. How did it become the ruler of our solar system?