Mighty Jupiter is the largest planet in our solar system with a mass 318 times that of the Earth. In fact, its mass is more than twice that of all the other planets in the solar system combined. Aside from mass, the planet also takes up a lot of space. It is 88,736 miles in diameter or more than 11.2 times the diameter of the Earth. By volume, Jupiter could hold over 1300 Earths with room to spare.
Jupiter is like a miniature solar system in its own right. In fact, one of its moons (Ganymede) is bigger than Mercury. Another, Callisto, is comparable in size and appearance to Mercury. These two moons make up two out of four of what are known as the Galilean Moons, so called because Galileo was able to observe them with his primitive telescope. You can see them too with just an average pair of binoculars on a good night.
The other two Galilean Moons are Europa and Io which are as interesting as any planet in our solar system. It is believed that Europa hosts an ocean beneath miles of ice. Evidence of life independent of light on our own planet has led to speculation that Europa may just harbor life around hydrothermal vents.
Io is famous as the most volcanically active body in our solar system. The volcanism is caused by tidal forces as Io orbits close to massive Jupiter. The stretching and pulling of Jupiter’s massive gravity and the counter pull of the other moons heats the interior of Io. To experience how bending and stretching produces heat, try bending a paper clip back and forth multiple times and then feel how the heat builds up at the point where it bends. Now imagine that on the scale of a paper clip the size of our moon!