1. Page #136 Feb. 5, 2013
Focus: Day & Night, Seasons, Rotation & Revolution
Objective: explain how the movement of the Earth affect different cycles
EQ: In what ways do planets move? What is affected by this movement?
HW: lesson review questions
Warm Up: 1. What is gravitational pull and how does it affect our solar system? 2. How do we get day and night?

2. OH Last Class! Why do the planets revolve around the sun?
What would happen without gravity?
What is gravitational pull and how does it affect our solar system?

4. Day & Night

5. Thinking Ahead What is a day? What is a year?
Are days and years the same on other planets? Why do you think so?

6. http://player. discoveryeducation. com/index. cfm

7. DIRECTIONS:
1. Color and label the sun
2. Color the day time half of the Earth green and blue
3. Color the night time half of the Earth black

8. The Earth spins on its axis
The spinning is called ROTATION
The direction of rotation is counterclockwise if you are looking at it as if you were floating over the North Pole

9. Each morning, the sun rises in the east and sets in the west
Each morning, the sun rises in the east and sets in the west. Read more:

10. As the Earth spins, part of the Earth is facing toward the Sun, and part is facing away from the Sun.

11. The part of the Earth facing the Sun has daytime

12. Day and Night The Earth rotates around once in 24 hours
The time it takes the Earth to rotate completely around once is what we call a day.
It's Earth's rotation that gives us night and day

13. the imaginary line that goes through the center of the Earth.
So the reason we have day and night is because the Earth
rotates.
Rotate means
to turn.
The Earth rotating on its
______
gives us day and night.
axis
Earth’s axis is
the imaginary line that goes through the center of the Earth.

14. Rotation Rotation: Planets spin on an axis One Rotation = Day
Fast Rotation = short day
Slow Rotation = long day
Rotation is measured in hours.
Earth’s Rotation: 24 hours (1 day)

15. But guess what! Rotating isn’t the only way the Earth moves in space!
The Earth also revolves.
Revolve – When one object moves around another object

16. How long does one revolution take?
It takes the Earth one year, or 365 ¼ days to orbit the sun.
Does anyone know what orbit means?
Orbit -
The path that an object follows as it revolves around another object.

17. Revolution Revolution: Planets revolve around the sun
Revolution = Year
Fast Revolution = short year
You would be older
Closer to the sun
Slow Revolution = long year
You would be younger
Farther from the sun
Revolution is measured in _days___
Earth’s Revolution 365 days (1 year)

18. Planet
Callisto
Ganymede
Europa
Dione
Rotation Period (hours)
36 hours
567 hours
909 hours
3,085 hours
Revolution Period (days)
6,396 days
350 days
2,349 days
54,938 days

19. Other planets Which planet do you think rotates the fastest? Why?
Which planet do you think has the longest revolution? Why?

20. Rotation Data Planet Length of Day Mercury 58.6 Earth days Venus
24 hr
Mars
24 hr 37 min
Jupiter
9 hr 55 min
Saturn
10 hr 32 min
Uranus
17 hr 14 min
Neptune
16 hr 6 min

21. Rotational Speed (km/h)
Rotational Speeds
Planet
Length of Day
Rotational Speed (km/h)
Mercury
58.6 Earth days
10.9
Venus
Earth days
6.5
Earth
24 hr
1670
Mars
24 hr 37 min
867
Jupiter
9 hr 55 min
45600
Saturn
10 hr 32 min
37000
Uranus
17 hr 14 min
10900
Neptune
16 hr 6 min
8460

22. Revolutions
Why are the revolutions of each planet different than Earth’s revolution?

23. Mercury Smallest planet Closest to Sun, moves around fastest (88 days)
no tilt of axis so poles are cold
Information about Mercury at
And at

24. Venus Nearly the same size as Earth
Slowest rotation of any planet (243 days)
Spins backwards
P MGN-114 May 26, 1993
This global view of the surface of Venus is centered at 90 degrees east longitude. Magellan synthetic aperture radar mosaics from the three eight-month cycles of Magellan radar mapping are mapped onto a computer-simulated globe to create this image. Magellan obtained coverage of 98 percent of the surface of Venus. Remaining gaps are filled with data from previous Venus missions -- the Venera 15 and 16 radar and Pioneer-Venus Orbiter altimetry -- and data from Earth-based radar observations from the Arecibo radio telescope. Simulated color is used to enhance small-scale structures. The simulated hues are based on color images obtained by the Venera 13 and 14 landing craft. The bright feature near the center of the image is Ovda Regio, a mountainous region in the western portion of the great Aphrodite equatorial highland. The dark areas scattered across the Venusian plains consist of extremely smooth deposits associated with large meteorite impacts. The image was produced by the Solar System Visualization Project and the Magellan Science team at the Jet Propulsion Laboratory Multimission Image Processing Laboratory. The Magellan mission is managed by JPL for NASA's Office of Space Science.
Lots of information about Venus at
Can see it in the night sky
without a telescope!

25. Earth 23 degree axis tilt (seasons!) Earth’s Rotation:
Liquid water – lots! - at surface
23 degree axis tilt (seasons!)
Earth’s Rotation:
24 hours (1 day)
Earth’s Revolution:
365 days (1 year)
Information and statistics at
Can see it without a telescope!

26. Mars
Can see it in the night sky
without a telescope!
25 degree axis tilt (seasons!)
Rotates once every ~24 hours and orbits the Sun once every 687 days
Very cold
No liquid water at surface; ice in poles
Information at
Image caption:
Global Mosaic of Mars Centered on Valles Marineris Date: Global mosaic of 102 Viking 1 Orbiter images of Mars taken on orbit 1,334, 22 February The images are projected into point perspective, representing what a viewer would see from a spacecraft at an altitude of 2,500 km. At center is Valles Marineris, over 3000 km long and up to 8 km deep. Note the channels running up (north) from the central and eastern portions of Valles Marineris to the dark area, Acidalic Planitia, at upper right. At left are the three Tharsis volcanoes and to the south is ancient, heavily impacted terrain. (Viking 1 Orbiter, MG07S SP) Image Credit: NASA

27. Jupiter diameter – 11x Earth  largest planet
completes one orbit in 4,333
Earth days, or almost
12 Earth years.
Jupiter rotates faster than any other planet. It takes 9 hours 56 minutes to spin around once on its axis, compared with 24 hours for Earth.
Which means it has the shortest day.
Jupiter was first visited by Pioneer 10 in 1973 and later by Pioneer 11, Voyager 1, Voyager 2 and Ulysses. The spacecraft Galileo orbited Jupiter for eight years. It is still regularly observed by the Hubble Space Telescope.
More information at

28. Saturn 9x the size of Earth 11 hour rotation / 29 year orbit
155,000 miles in diameter / ½ mile thick – rings
Saturn is the sixth planet from the Sun and the second largest:
orbit: 1,429,400,000 km (9.54 AU) from Sun diameter: 120,536 km (equatorial) mass: 5.68e26 kg
Ring image from
More information at

29. What do think causes the seasons?
We begin our workshop with a discussion of some of the misconceptions about seasons.
Squirrel image taken at Kennedy Space Center
Blue Heron also taken at Kennedy Space Center
What do think causes the seasons?

30. What Causes Earth’s Seasons?
Earth’s axis is tilted 23.5 degrees – it always points in the same direction (Polaris, the North Star) as we orbit our Sun once a year
This tilt causes the hemispheres to alternate in the amount of our Sun’s light and heat they receive through the year
More information is at
This image shows the reason Earth experiences seasons.  Points we discuss using this image are:
1) Earth’s orbit around the Sun is only slightly elliptical
2) Earth’s path around the  Sun brings us closer to the Sun in January.  Many students think we have seasons because Earth is sometimes closer and sometimes farther from the Sun.  This is correct, however, we actually are closer to the Sun in January in the Northern Hemisphere!
3) Earth’s seasons are caused by Earth’s tilt on its axis (~23 degrees).  Earth’s axis essentially is fixed  - it always points to the same place in the sky (on the celestial sphere) – towards Polaris. As we orbit the Sun each year, first one polar region is tilted toward the Sun, and then the other is tilted toward the Sun. When the north polar region is tilted toward the Sun (summer) the south polar region is tilted away (winter).
Notes: Earth’s tilt does change over very long time periods, but for the most part, it moves between 22 and 23 degrees. Earth’s axis also wobble a bit, but over time periods of thousands of years, pointing toward different stars.

31. Northern Hemisphere Summer
At this point, we have participants use styrofoam balls with sticks and a bright lamp to model the seasons on the Earth, with the axis of the “Earth” tilted toward a “North Star” that has been placed high in the corner of the room.
For part of our orbit the northern half of Earth is tilted toward the Sun. This is summer in the northern hemisphere; there are longer periods of daylight, the Sun is higher in the sky, and the Sun's rays strike the surface more directly, giving us warmer temperatures. The north pole is in constant daylight!
When the northern half of Earth is tilted toward the Sun, the southern hemisphere is tilted away. People in the southern hemisphere experience the shorter day lengths and colder temperatures of winter.
During winter in the northern hemisphere, our northern axis continues to point to the North Star, but, because we have moved in our orbit around the Sun, our northern hemisphere now points away from our Sun. The north pole is completely dark and other places in the northern hemisphere experience the shorter day lengths and colder temperatures of winter as the Sun traces a lower arc across the southern sky and the Sun's rays strike the surface at a lower angle. When it is winter in the northern half of Earth, the southern hemisphere, tilted toward our Sun, has summer.
During fall and spring, some locations on Earth experience similar, milder, conditions. Earth has moved to a position in its orbit where its axis is more or less perpendicular to the incoming rays of the Sun. The durations of daylight and darkness are more equally distributed across all latitudes of the globe.
Solstices occur when Earth's axis is pointed directly toward our Sun. This happens twice a year during Earth's orbit. Near June 21 the north pole is tilted 23.5 degrees toward our Sun and the northern hemisphere experiences summer solstice, the longest day of the northern hemisphere year. On that same day, the southern hemisphere is tilted 23.5 degrees away from our Sun and the southern regions of Earth experience the shortest day of the year — the winter solstice.
The second solstice occurs on December 21 or 22 when the north pole is tilting 23.5 degrees away from our Sun and the south pole is inclined toward it. This is the shortest day of the year in the northern hemisphere — the northern hemisphere winter solstice.
Twice each year, during the equinoxes (“equal nights”), Earth's axis is not pointed toward our Sun, but is perpendicular to the incoming rays. During the equinoxes every location on our Earth (except the extreme poles) experiences 12 hours of daylight and 12 hours of darkness. The vernal or spring equinox occurs in the northern hemisphere on March 21 or 22 (the fall equinox of the southern hemisphere). September 22 or 23 marks the northern hemisphere autumnal or fall equinox.
As Earth orbits our Sun, the position of its axis relative to the Sun changes. This results in a change in the observed height of our Sun above the horizon. For any given location on Earth, our Sun is observed to trace a higher path above the horizon in the summer, and a lower path in the winter. During spring and fall, it traces an intermediate path. This means that our Sun takes a greater amount of time tocross the sky in the summer and a shorter amount of time in the winter. This effect is greater as you move toward the poles; people living near the equator experience only small changes in daylight during the year. The change is more extreme toward the poles.
From the National Maritime Museum
During the northern hemisphere summer solstice, Earth is tilted such that the Sun's rays strike perpendicular to the surface at the Tropic of Cancer (23.5 degrees north latitude, corresponding to the tilt of Earth's axis). At (solar) noon, our Sun is directly overhead in this location (and at a decreasing height above the horizon north and south of the Tropic of Cancer). At locations north, our Sun will be at its highest position above the horizon and will take the greatest amount of time to cross the sky. All northern locations have more than 12 hours of daylight. All locations south experience less than 12 hours of daylight. Locations above the Arctic Circle (north of 66.5 degrees latitude; 90 degrees minus the tilt of Earth's axis) receive 24 hours of sunlight. Locations below the Antarctic Circle (66.5 degrees south latitude) experience 24 hours of darkness.
During the northern hemisphere winter solstice, the Sun's incoming rays are perpendicular to the Tropic of Capricorn at 23.5 degrees south latitude. The Sun's path is the lowest above the horizon in locations north of the equator, and these regions experience the shortest day of the year. Between the winter and summer solstices, daylight increases as Earth continues its orbit around our Sun.
During the equinoxes, sunlight strikes perpendicular to the surface at Earth's equator. All locations on Earth, regardless of latitude, experience 12 hours of daylight and 12 hours of darkness. The spring equinox marks the change from 24 hours of darkness to 24 hours of daylight at Earth's poles . In these extreme locations, our Sun moves above the horizon at the spring equinox and does not go below the horizon until the fall equinox.
More daylight hours, more direct sunlight

32. That tilt gives us seasons!
But why do we have four seasons?
It’s because the Earth’s axis is tilted.
Take a good look at our globe. It‘s not tilted like that because it looks nice. No way. That’s the way the Earth is tilted in space.
That tilt gives us seasons!

33. Look at this diagram. Notice how the Earth is always tilted in the same direction. As the Earth __________ the part of Earth tilted toward the sun changes.
revolves

35. During part of the year, the North Pole points away from the sun
During part of the year, the North Pole points away from the sun. This season is _.
winter_____

36. During part of the year the North Pole tilts towards the sun
During part of the year the North Pole tilts towards the sun. This season is
________.
summer

37. When the North Pole is tilted toward the Sun, the Sun travels higher overhead in the sky. The Sun’s rays shine straighter down on that part of the Earth. It is summer in that part of the Earth.
It’s like pointing a flashlight at a piece of paper. When you hold the flashlight straight above the paper, the rays from the flashlight shine down straighter.

38. When the North Pole is tilted away from the Sun, the Sun stays lower in the sky. It is then winter in that part of the Earth.
If you point your flashlight at a piece of paper at an angle, the rays from the flashlight spread out.

40. In the Spring and Fall EQUINOX
A day lasts 12 hours and a night lasts 12 hours at all latitudes. Sunlight strikes the earth most directly at the equator.

41. In the Summer and Winter
SOLSTICE
During the winter the Northern Hemisphere day lasts fewer than 12 hours and the Southern Hemisphere day lasts more than 12 hours.
During the winter solstice, the North Pole has a 24-hour night and the South Pole has a 24-hour day.
Sunlight strikes the earth most directly at the Tropic of Capricorn.

42. In the Summer and Winter
SOLSTICE
 During the summer solstice the Northern Hemisphere day lasts more than 12 hours and the Southern Hemisphere day lasts fewer than 12 hours.
During the summer, the North Pole has a 24-hour day and the South Pole has a 24-hour night.
Sunlight strikes the earth most directly at the Tropic of Cancer.

43. Why does the earth experience seasons?
Because the Earth is tilted, different parts of the planet get different amounts of sunlight at different times of the year.

44. Independent Practice B. Draw pictures A and B.
Label the picture that shows the red dot is in the season of summer. Label the picture that shows the red dot in the season of winter. A. B.

47. Page # January 17, 2011
Title: Rotation and Revolution
Objective: analyze how Earth’s movement affects day and night
HW: all work is due by Wednesday, check calendars
Warm-Up:
Does the Earth move around the Sun?
How do we get day and night?

48. Title: Lets Start a Revolution !
RIGHT PAGE 52
December 2, 2008
Title: Lets Start a Revolution !
Objective: Describe a planet and the effects of a planet’s movement.
Words to Know:-
orbit - path of an object in space as it moves around another object.
year- amount of time a planet takes to revolve around the sun.
day- how many hours does it take a planet to rotate on its axes.