1. The Apparent Motions of Celestial Objects
Mr. Cloud
Earth Science

2. Apparent motion: The movement a celestial object appears to make.
What other apparent motions can you name?

3. Celestial sphere (hemisphere): model used to map apparent motions of celestial objects
Zenith: point directly above the observer
Horizon: is the apparent line that separates Earth from sky
Azimuth: the angular direction of a celestial body from the observer, usually measured from north.

4. What causes apparent motion?
Earth’s rotation causes apparent motion of celestial objects.
The Earth rotates West  East.
Causing celestial objects to rise due east and set west.
360 degrees/24 hrs = 15o/hr

5. Circumpolar Stars
Circumpolar Stars: Stars that appear to make one full revolution around Polaris in 24 hrs. These stars do not appear to rise or set.
Circumpolar constellations: groupings of stars that appear to make one full revolution about Polaris in 24 hrs; can be seen all year round
Keck Observatory: Mauna Kea, Hawaii

6. Apparent Motion of the Sun