Can I See It?
      Yes you can, and you don't need a telescope to see the ruler of the night sky. When Jupiter is visible, it is usually the brightest light in the night sky. The only objects that are brighter are the Moon and Venus. There are times when you can see Jupiter in  both the early morning and evening.  Jupiter and its moons are so large that you can see the basic color of the giant planet with just a pair of binoculars. If you have
      patience, you can usually pick out one or more of the largest moons of Jupiter with your binoculars! 
The way to see the moons with binoculars is to steady them against something solid and look at the planet. After your eyes have had a minute or two to  adjust to the light, you will see one or more small points of light. These lights will be a different color than the stars. Congratulations, you have found Jupiter's moons! 

 How Big Is It?
      Jupiter is so large that it is hard for us to grasp just how big it is. Jupiter is over 85 thousand miles in diameter, dwarfing  Earth, which is a little over 7,600 miles in diameter. Jupiter is so large that 1300 Earths could fit inside it! Put another way, if  you had a ball that was about the size of a dime, Jupiter would be the size of a basketball! 
 

 How Many Moons Does It Have?
      Jupiter is like a miniature solar system. The giant planet has at least sixteen moons, and possibly more. The four largest moons of      the planet, called the Galilean moons, are in the picture at the right. The two largest moons are both bigger than the planets Pluto and Mercury, and the largest of them is almost the size of Mars!   In addition to being very large, these four moons of Jupiter are also very interesting. Europa, the top moon, is a giant ball of ice. Io, the second moon in the picture, has active volcanoes! Io is the only place in the solar system besides Earth where we have  found volcanoes. Callisto, the third moon in the picture, is covered with thousands of craters, which are the result of collisions  with other objects in space. Ganymede, the largest moon, is made up of rocky ice.

 How Did It Get Its Name?
      The Romans named Jupiter after the supreme god in their religion. This is easy to understand, since it is the largest planet in the sky. Many of the planet's moons have been named for Jupiter's daughters. 

 What Is It Made Of?
      As large as Jupiter is, it is not a rocky planet like Earth or Mars. Jupiter is a gas planet, which means that is not solid at all, but instead is a giant cloud made up mostly of the gas elements hydrogen and helium. You may be wondering "If Jupiter is just gas,  how can it be so large and what holds it together?". These are both excellent questions.  Most things in the universe are not solid, but are giant balls or clouds of gas, and Jupiter is the same. Our Sun is a ball of gas that also gives us heat and light. What holds Jupiter together is the same thing that makes something drop to the ground here on Earth. That force is called gravity. 
      Billions of years ago, Jupiter started forming when several clouds of gas began to accumulate in the same place. In much the same  way that you build a ball of snow for a snowman, more and more clouds joined the crowd until the planet began to take shape. As  the original ball of gas became bigger, it attracted, or gathered in, other clouds of gas. The larger the ball got, the planet's  gravity, or force that attracted the other clouds, also grew. This continued until Jupiter grew to its present size.

 What's It Like on the Surface?
      Since Jupiter is a gas planet, it doesn't have a surface. This means that if you tried to land on the planet, you would not be able  to find anything solid to land on. This does not mean that Jupiter does not have its own strange kind of "weather".  The clouds that make up Jupiter are constantly swirling around the planet, driven by winds that average over two hundred miles per hour. The winds create an ever-changing pattern of what we call storms on Earth. The most famous of these storms is the Great Red spot, which you can pick out in the picture of Jupiter and its moons at the top of the page