There are 8 planets in our solar system. These planets all go around the Sun. Some of these planets are big. Some of these planets are small.
Some planets are closer to the Sun. There is less distance between the Sun and these planets. These planets move faster. These planets are hotter.
Some planets are farther from the Sun. There is great distance between the Sun and these planets. These planets move slower. These planets are colder.
Jupiter is the biggest planet in our solar system. Its diameter is 11 times more than Earth. Jupiter is the fastest spinning planet. It looks very different from Earth. It has rings that go around the planet. On Earth, one day has 24 hours. On Jupiter, one day is about 10 hours. Scientists think it has 79 moons.
Mercury is the smallest planet in our solar system. It has been shrinking. This means it is getting smaller. Mercury is only a little bigger than Earth's moon. It has a much smaller mass than Earth. If you went to Mercury, you would weigh less. Earth has 365 days in a year. On Mercury, one year only has 88 days! It does not have any moons.
Scientists used to think Pluto was a planet. Now we know Pluto is a dwarf planet. It is a smaller kind of planet. It is a cold and icy planet. It has 5 moons. It has longer days than Earth. One day on Pluto is about 153 hours!
These planets are different. There are small and hot planets. There are big and cold planets. There is a lot we don't know about our planets. We are always learning more about our solar system.