All About Jupiter for Children： Astronomy and Space for Kids - FreeSchool

Jupiter, the fifth planet from the sun, is also the largest planet. Aside from the sun, Jupiter is the largest object in the solar system. It is called a gas giant because it is so large, and it is made mostly of gases, hydrogen, helium, methane, and ammonia. Jupiter is made of many of the same materials as stars. If it had been about 80 times more massive than it is, it might have become a star instead of a planet. It would take more than 300 Earths to equal Jupiter's mass. It is twice as massive as all of the other planets in the solar system put together, and has a diameter of more than 88,000 miles, or 142,000 kilometers. It is so large that if it were a big jar, more than 1,300 Earths could fit inside of it. Jupiter has been observed for thousands of years, and was known to the ancient Romans, who named it after Jupiter, the king of the gods. It is the third brightest object in the night sky, dimmer only than the moon and Venus. Jupiter is so far from the sun that it takes more than 11 Earth years for it to travel around once. Although Jupiter's orbit is much longer than the Earth's, its day is much shorter. The Earth rotates once every 24 hours. Jupiter rotates once about every 9 hours, faster than any other planet. Spinning so quickly causes strong weather patterns in the clouds surrounding the planet. This makes Jupiter the stormiest planet in the solar system. There is a permanent whirlpool of storms on Jupiter known as the Great Red Spot, which has been churning for centuries. It was first observed more than 350 years ago by Robert Hooke, and can be seen using a telescope. The Great Red Spot is huge. In fact, it is larger than the Earth. However, recent observations have shown that the Great Red Spot is shrinking, and is currently at the smallest size it has ever been observed. Temperatures in Jupiter's clouds are far below freezing, negative 234 degrees Fahrenheit or negative 145 degrees Celsius. But near the center, it is much, much hotter. Core temperatures on Jupiter may reach 43,000 degrees Fahrenheit or 24,000 degrees Celsius, hotter than the surface of the sun. Jupiter has at least 67 moons. Fifty-five of these moons are very small, only a few miles or kilometers wide. The four largest moons, Io, Europa, Ganymede, and Callisto, are large enough to be seen from Earth with a telescope. They were discovered by the Italian astronomer Galileo Galilei about 400 years ago. Ganymede is the largest moon in the solar system, and is even larger than the planet Mercury. Jupiter also has a system of thin rings around it, although these rings are much, much smaller than Saturn's. Made mostly of tiny dust particles, they are so thin and so hard to see that no one knew they were there until NASA's Voyager 1 probe approached Jupiter in 1979. Eight spacecraft have either passed or visited Jupiter since 1973. On August 5, 2011, NASA launched a ninth spacecraft, called Juno, to further study the planet. Juno is expected to achieve orbit around the planet in July of 2016, and there is no knowing what new, exciting information it will reveal about Jupiter, the giant of the solar system. I hope you enjoyed learning about Jupiter today. Goodbye till next time!