1. 9/29/2017
Friday

2. Science log Q1 week 5
Friday, September 29:
Describe how you know that the Earth rotates counterclockwise, as seen looking down from the North Pole.
Update Moon Log

3. 17. Earth’s rotation
Earth appears to rotate counterclockwise if seen from above and that in your model, you were turning to the left to represent this.
On your diagram page 32, make a note explaining the rotation on the axis, it takes 24 hours to completely rotate between day and night.

4. 18. Day and night with globe
How should I set up the model?
Where should the Sun be, and where should Earth be?
Demonstrate midnight, sunrise, noon, sunset

5. 19. Day and night think questions page 34 answers on 35
Notebook sheet 7, Day/Night Think Questions,
A. Focus on the first question: Why is it dark at night?
Discuss in your groups
answer question number 1
B. At any given time, how much of Earth is in daylight and how much is in darkness?
What makes the Sun “come up” and “go down”?
Does the Sun come up in the morning all over the world? Explain
Finish the rest on your own

6. 20. Summarize day and night
The Sun is a luminous object that gives off light. The Sun is a source of light that illuminates Earth during the day.
When light falls on an object, the portion in the path of the light is illuminated. The area behind the object is in the shadow, in the dark.
When light falls on a spherical object, like a planet, exactly half is in the light, and half is in the dark.
The dark side of the sphere is in its own shadow, not the shadow of another object.
Day and night are the names given to the light and dark halves of a planet.

7. 20. Summarize day and night
From our position on Earth, it looks like the Sun circles Earth once every day. In reality, the Sun is stationary (essentially) and Earth rotates on its axis once every day, giving the illusion of a Sun that rises and sets.
If a planet did not rotate, it would have a day side and a night side just the same as a planet that does rotate.
The difference is that, when a planet rotates, the part of the planet experiencing day and the part experiencing night changes continually; if a planet were not moving (rotation or revolving around its star), one half would experience day all the time, and the other half would experience night all the time.
One complete rotation of our planet accounts for one complete day.
For Earth, one rotation requires 24 hours (1 day)

8. 21. Revolution How does Earth move relative to the Sun?
Earth revolves (travels around) around the Sun
Revolution is counterclockwise, just like the rotation
How long does it take for Earth to make one revolution around the Sun?
1 year, or days
People often think that Earth moves in an oval, or elliptical, shape as it orbits the Sun.
In fact, the orbit of Earth is nearly circular.

9. 21. Revolution
Can you explain how the revolution of Earth is different from the rotation of Earth.
Revolution is the orbit of Earth around the Sun’
Rotation is Earth’s spinning on its axis.
Earth has a North Pole and a South Pole.
These are the north and south ends of an imaginary axle, called an axis, on which Earth rotates.
How long does it take for Earth to rotate (turn around once) on its axis?
1 day, or 24 hours it spins at a 23.5 degree angle relative to the plane of its orbit.

10. 23. North Star
There is a star in the night sky called Polaris, or the North Star. It is positioned almost directly over Earth’s North Pole.
Earth’s North Pole points toward the North Star— summer, fall, winter, spring, day, and night.
That’s why the North Star has been a navigation aid to seafarers and explorers in the Northern Hemisphere for centuries.

11. 23. North Star
In our Earth/Sun system, we need a North Star. You will have to visualize the North Star through this wall and way, way off in the distance.
The North Pole of our model Earth will always point its axis at the North Star as it revolves around our model Sun.
We can use this star to remind us of approximately where the North star is in the sky.

12. 24. Vocab page 31 also add to your index
North Star: the reference star pointed to by Earth’s North Pole
Orbit: the path and length of time one object takes to travel around another object
Revolution: traveling around something. Earth takes days around the Sun in a circular motion

13. 25. Self-assessment
Draw a line of learning and review and revise your answer on page 29 quick write.

14. Wrap up
Earth is tilted 23.5 degrees on its axis, and the axis always points in the same direction, toward the North Star.
One rotation of Earth takes 24 hours, producing the day/night cycle on Earth.
Earth revolves around the Sun in a circular orbit once every days.
Day and Night