How old is Earth?
How large is Earth?
What is Earth made of?
Why does Earth spin?
Why don't we feel Earth move?
How much does Earth weigh and how is this measured?
What is Earth's location in space?
What are the highest and lowest temperatures ever measured on Earth?
What is the atmosphere of Earth made of?
What keeps our atmosphere attached to Earth?
How thick is Earth's ozone layer?
How much water does Earth have?
How did Earth get its name?