Question | Answer |
Our _____ _____ includes the sun, planets and many smaller objects. | solar system
|
The average distance between the earth and the sun; approximately 150 million kilometers. (symbol AU) | astronomical unit
| How far does light travel in 1 s? | 300 km/s
| The inner planets are also called _______ planets because their surfaces are dense and rocky. | terrestrial
| The ____ planets are the planets closest to the sun. | inner or terrestrial
| The inner planets are Mercury, Venus, Earth and ______. | Mars
| The outer planets are Jupiter, Saturn, ____ and ______. | Uranus and Neptune
| The outer planets are composed mostly of _____. | gases
| The planet closest to the sun. | Mercury
| It takes Mercury to rotate once in ______ days. | 58
| The number of days it takes Mercury to complete one revolution around the sun is _____. | 88
| On this planet, the sun rises in the west and sets in teh east. | Venus
| This planet is called the Earth's twin. | Venus
| The atmosphere of Venus is very high due to its _______ effect. | greenhouse
| Earth has _____ rotation because it spins in a counterclockwise direction or in the same direction as the sun's rotation. | prograde
| Venus has a _____ rotation because it spins in a clockwise direction. | retrograde
| The only planet that supports life is ____. | Earth
| Earth's period of revolution is ____ days. | 365
| The planet that showed evidence of once having water is ____. | Mars
| many scientists believe that water is frozen beneath the soil and stored in polar ice caps of this planet. | Mars
| mars has ____ large volcanic systems. | two |