There are eight planets in the Solar System, and each one is very different. Some planets, like Jupiter and Saturn are very large. Others, like Mercury and Mars are smaller. Jupiter has moons that are larger than Mercury. The planets also have different atmospheres. Uranus, Jupiter and Saturn have atmospheres of hydrogen and helium. The atmosphere on Venus is made up of carbon dioxide. Earth has a nitrogen and oxygen atmosphere. Neptune’s atmosphere is mostly hydrogen. The planets also have different temperatures. Uranus is the coldest and Venus is the hottest.
Each of these planets takes a different amount of time to travel around the Sun. For the Earth, this journey is 365.25 days long, but for a faraway planet like Neptune, it takes 165 years. There are smaller objects which do not circle the Sun, but around these planets. They are called satellites, or moons, just like Earth's only natural satellite.
True or False? True False
1. There are 8 planets in the Solar System
2. Venus is the coldest planet
3. The Earth travels around the Sun in 165 years
4. The Earth has only one satellite
5. Mercury and Mars are smaller than Jupiter
1 true
2 false
3 false
4 true
5 true