1. The Constellations of our Galaxy
STARS
The Constellations of our Galaxy

2. Differentiate between astrology (the belief that celestial bodies have an influence on humans) and astronomy (the science that deals, in part, with the observations of celestial bodies). Constellations are groups of stars that form a pattern or a shape in the sky. There are 88 of them and they help people orient themselves and determine the time of the year.
The Earth’s revolution around the sun causes us to see different constellations at different times of the year. Their appearance changes also
In ancient times, astronomers did not fully understand how Earth, the Sun, and the stars moved. Nor did they have any idea the Universe is so vast. But they were keen observers of the sky and tried very hard to make sense of it. People had already imagined that the constellations might be important symbols, telling stories of their gods and other myths. It was not a big step to suppose that the changing positions of the constellations at different times of the year might be important to people and events on Earth. 2

3. Born under the sign of…
* A light year is the distance light travels in one Earth year. This is almost 6,000,000,000,000 (6 trillion) miles! One light year is 25 million times farther than the moon, or over 60,000 times farther than the Sun. Remember, nothing in the Universe travels faster than light! 3

5. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 5

6. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac? Earth’s revolving.
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 6

7. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year? YES
Are the constellations themselves moving?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 7

8. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
Are the constellations themselves moving? NO
What causes this apparent change in positions?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 8

9. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
Are the constellations themselves moving?
What causes this apparent change in positions? As Earth orbits the Sun, our perspective changes
Do all stars appear in different positions at different times of the year?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 9

10. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
Are the constellations themselves moving?
What causes this apparent change in positions?
Do all stars appear in different positions at different times of the year? All except Polaris
Why is Polaris the only star that appears “fixed”?
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 10

11. Constellations
What is changing at the same (annual) timescale that we are observing the changing zodiac?
Do the constellations appear to change positions in the night sky as Earth travels around our Sun throughout the year?
Are the constellations themselves moving?
What causes this apparent change in positions?
Do all stars appear in different positions at different times of the year?
Why is Polaris the only star that appears “fixed”? Earth’s axis points to Polaris
1)Earth is revolving around our Sun once each year
2) Yes, the constellations will appear in different positions at different times of the year
3)No
4) (The different orbital positions of the Earth throughout the year cause us to view the night sky from different perspectives)
5) (From a northern hemisphere perspective, all stars appear to change positions except Polaris, the “Pole Star,”which is the only star that appears “fixed”)
6) (Their answer should include the idea that, because our axis points to Polaris, it appears to be fixed, similar to the way the center of a spinning disk appears to remain fixed while its periphery moves) 11