Across
- 2. Early astronomers thought that the Earth was _______.
- 4. Early astronomers thought that ________ is at the center of the Universe and that all other objects in space revolved around Earth.
- 5. The appearance of the Sun traveling across the sky during the day is the result of the Earth’s _____________.
- 6. After a long and slow process, astronomers began to believe (and then see) the Earth is a ________.
- 7. Earth has a 23.5 degree axial tilt that causes Earth’s __________.
- 8. It takes 1 day for Earth to make one ___________ rotation on its axis.
- 11. Astronomers believe that Earth began to form about 4.7 __________ years ago.
- 12. Earth is 24,901 miles ___________.
Down
- 1. Earth spins (or __________) on its axis.
- 3. Day and night occur on Earth as the Earth rotates along its _______, causing half of the Earth to be facing the Sun (day) and half of the Earth to be facing away from the Sun (night).
- 5. It takes 1 year for Earth to make one complete ____________ around the Sun.
- 9. All of the planets except Earth are named for Greek or Roman gods. Earth comes from the English word ertha and the German word erda. Both words means “the ___________.”
- 10. _________ is the 3rd planet from the Sun.
- 13. 1 ______ on Earth (the time it takes to make one complete rotation) is not 24 hours, but rather 23 hours and 56 minutes and 4 seconds.