Question 24 - Reading: Level M Practice Test for the TABE Test

Jupiter is the largest planet in the Solar System. It is the fifth planet from the Sun. Jupiter is a gas giant, meaning a large planet with a solid core but a thick atmosphere so that most of the planet is made up of gas. The other gas giants are Saturn, Uranus, and Neptune.

Jupiter was named for the king of the gods. The Greeks called him Zeus, and the Romans called him Jupiter. And Jupiter is a fitting name for this king of the planets. Jupiter is the biggest planet with a diameter eleven times bigger than the diameter of Earth. Its mass is about 318 times the mass of Earth. Its mass is more than twice the mass of all the other planets in the Solar System put together.

Jupiter is so big, it can be seen even without using a telescope. It is the third brightest object in the night sky. Only the Earth’s moon and Venus are brighter.

Jupiter has 79 moons. About 50 of them are very small—less than five kilometers wide. The four largest moons of Jupiter are Io, Europa, Ganymede, and Callisto. They are called the Galilean moons because Galileo Galilei discovered them in 1610. Ganymede is the largest moon in the Solar System. Its diameter is larger than the planet Mercury’s.