What is the approximate age of Earth?
What layer of Earth do we live on?
What is Earth’s only natural satellite?
What causes day and night on Earth?
What gas makes up most of Earth’s atmosphere?
What is the imaginary line that divides Earth into Northern and Southern Hemispheres?
Which layer of Earth is made mostly of molten rock?
How long does it take Earth to orbit the Sun once?
What is the name of Earth’s outermost rigid shell made of crust and upper mantle?
What force keeps Earth in orbit around the Sun?
