1. 7.1 Ancient Astronomy
Homework: Page 276 # 6- 8

2. Learning Goals
I can explain how ancient peoples benefitted from studying the sky.
I can explain how ancient clocks work.
I can explain how ancient peoples determined that the Earth is spherical.

3. Early skywatchers paid a lot of attention to the sky
Early skywatchers paid a lot of attention to the sky. This enabled them to developed accurate calendars, which they used to predict the seasons and other events that were important to them in their daily lives.
Different cultures have different reasons for watching the sky. For example, the ancient Egyptians watch for the star called Sirius to rise every year because they knew that the Nile River would flood soon after.

4. Revolution around the Sun takes 365. 24 days
Revolution around the Sun takes days. Earth’s rotation on its axis takes 24 hours.
Careful observations of ships “disappearing” below the horizon, the changing appearance of the sky when traveling, and Earth’s shadow viewed during eclipse led the early Greeks to infer the Earth is a sphere.

7. What is astronomy?
Astronomy is the study of the night sky.

8. Match each term with the correct definition.
a) planet vi.. orbits stars and reflects light
b) meteorite vii. stony or metallic matter that has fallen to Earth
c) moon i. Earth’s natural satellite
d) asteroid belt iii. located between mars and Jupiter
e) star ii. emits light
f) Earth iv. much of its surface is covered with water
g) comet v. has a tail consisting of gas and dust

9. 3. Match each cause to an effect :
a. Earth’s rotation on its axis cause…..
iv. day and night
b. Earth’s revolution around the Sun causes….
v. yearly periods
c. The Moon’s gravitational pull on Earth causes….
ii. ocean tides
d. Earth’s tilt on its axis causes….
i. the seasons
e. The Sun’s gravitational pull on Earth causes…..
iii. Earth’s orbit

10. 4. Describe how people navigated during the olden days.
Fixed patterns of stars in the night sky helped people navigate on land and in water.

11. Polaris

12. 5. What is a celestial object
5. What is a celestial object? What is the importance of knowing these objects during the early times?
A celestial object is any object that exists in space (examples include the moon, planets and stars). These objects were used to predict seasons and eclipses.

13. 6. Who were the first astronomers for whom we have evidence of detailed astronomical observations?
The Mesopotamians were the first astronomers for whom we have evidence of detailed astronomical observations.
7. What unit of time does one rotation of Earth correspond to?
It corresponds to one day.

14. 8. Give 2 examples of why early cultures depended on their observations of the sky.
It allowed people to predict seasons which in turn allowed people to predict spring rains, annual river flooding, and migration of animal herds. Thus, the observations helped cultures plan for the planting of crops and prepare for hunting.

15. 9. Describe the first clocks that were used around 6000 years ago?
The first clocks were sticks in the ground. The length and direction would indicate the time of year and time of day.

16. 10. A friend believes that Earth is flat
10. A friend believes that Earth is flat. Construct an argument to convince your friend that Earth is a sphere.
1. The hull and then the masts of ships appeared to descend below the horizon as ships sailed away.
3. During a lunar eclipse, the shadow of Earth on the moon was curved.
2. The appearance of the sky changed as travellers journeyed farther north or south.