1. Earth and Moon in Space

2. Earth Moves Earth moves in space
Earth spins around an imaginary line called an axis
The axis is an imaginary line passing through the poles and the center of the Earth

3. Rotation Rotation is the spinning of the Earth on its imaginary axis
Earth makes one complete rotation every 24 hours
Rotation of the Earth causes day and night as a point on the Earth rotates toward or away from the sun

4. Revolution
Earth moves around the sun in a regular, curved path called an orbit
Revolution is the movement of Earth in an orbit around the sun
Earth takes 365¼ days to make one revolution around the sun (one year)
Earth rotates on its axis and revolves around the sun at the same time

5. Seasons Seasons are caused by the tilt of the Earth on its axis.
The hemisphere of the Earth that is tilted toward the sun receives more of the sun’s heat and light and its temperatures are warmer.
Summer happens in a hemisphere when the hemisphere is tilted toward the sun.

6. Seasons Winter happens when a hemisphere is tilted away from the sun.
When a hemisphere is tilted away from the sun, it receives less heat and light and the Earth’s temperatures are cooler.

7. Seasons

8. Solstice
Solstice is point at which the sun reaches its greatest distance north or south of the equator.
In the northern hemisphere, the winter solstice happens around December 21 or 22.
The winter solstice has the fewest daytime hours.

9. Solstice
In the northern hemisphere, the summer solstice happens around June 21 or 22.
The summer solstice has the most daytime hours.

10. Equinox
When the sun reaches an equinox, it is directly above the Earth’s equator.
At the equinox, the number of daytime and nighttime hours equal each other all over the world.
In the northern hemisphere, the spring equinox is March 20 or 21 and the fall equinox is September 22 or 23.

11. It's Just a Phase It's Going Through...
The Moon
It's Just a Phase It's Going Through...

12. Moon
Our planet's large natural satellite, the Moon, is the easiest astronomical object to observe.
The only "scientific instrument" you'll need at first is a pair of eyes.
Picture from NASA

13. The Moon's Orbit Rotation Revolution
Moon is spinning on its axis, once every 27.3 days
Revolution
The moon orbits around the Earth
Moon revolves around the Earth once every 27.3 days

14. Why do we never see the DARK SIDE?
Synchronous Rotation is the reason we never see the dark side of the moon.
Over the millennia, the Moon has become "locked" into a special kind of motion around the Earth.
It rotates on its axis at the same pace as it revolves around the Earth
As a result, the Moon keeps the same face toward us throughout its orbit.

15. Phases
The lighted side of the moon always faces
the sun.

16. New Moon
What we see
New moon occurs when the moon is between the sun & the Earth.
The dark side of the moon is facing the Earth.
What is happening from above. E
Sunlight

17. Full Moon
What we see
The full moon occurs when the Moon & the Sun are on opposite sides of the Earth.
The lighted side of the moon is facing Earth.
What is happening from above. E
Sunlight

18. Blue Moon
When there is more than one full moon in a month, the second moon is called a blue moon.
A blue moon happens every two years on average.
The phrase, “Once in a blue moon” means very rarely or very seldom or almost never.

19. First Quarter Moon What we see
The First quarter moon occurs when the moon is halfway between new and full.
As seen from the Earth, half the moon’s disk is illuminated.
What is happening from above. E
Sunlight

20. Third Quarter Moon What we see
The Third or last quarter moon occurs halfway between the full moon & the new moon.
As seen from the Earth, half the moon’s disk is illuminated.
What is happening from above. E
Sunlight

21. Waxing
When the moon is between new & full, the visible part of the moon is increasing.
This is called waxing E
Sunlight

22. Waning
When the moon is between full & new, the visible part of the moon is decreasing.
This is called waning. E
Sunlight

23. Crescent Moon
Full Moon
When the moon is between New & 1st Quarter it is called a waxing crescent. E
3rd Quarter
1st Quarter
When the moon is between 3rd & New it is called a waning crescent.
Waning
Crescent
Waxing Crescent
New Moon
Sunlight

24. Gibbous Moon
Full Moon
Waning Gibbous
When the moon is between 1st Quarter & Full it is called a waxing gibbous.
Waning
Gibbous E
3rd Quarter
1st Quarter
When the moon is between Full & 3rd it is called a waning gibbous.
Waning
Crescent
Waxing Crescent
New Moon
Sunlight

25. Moon Movie

26. Link to current phase of the moon
Link to moon phases pictures and lunation movie

27. Forces governing planetary motion
Sun and planets or
Earth and moon

28. Force A force is a push or pull one body exerts on another
A force causes an object to accelerate in the direction of the force

29. Inertia Tendency of an object to resist any change in motion
A moving object stays moving

30. Inertia
An object that is not moving will stay still, unless a force acts on it
An object at rest stays at rest

31. Inertia
A sliding hockey puck moves at the same speed and direction until it hits a wall or a stick
Velocity is constant, no acceleration

32. Inertia
If a force (a moving hockey stick or the wall) acts on the puck, then it will change direction
Velocity changes

33. Mass and Inertia More mass an object has, the more inertia it has
More mass, harder to change the motion

34. Newton’s First Law
An object moving at a constant velocity keeps moving at that velocity unless a net force acts on it.

35. Newton’s First Law
An object at rest, stays at rest unless a net force acts on it.

36. Newton’s First Law
Newton’s first law is sometimes called the Law of inertia

37. 1st Law
Unless acted upon by an unbalanced force, this golf ball would sit on the tee forever.

38. 1st Law
Once airborne, unless acted on by an unbalanced force (gravity and air – fluid friction), it would never stop!

39. It’s a force we sometimes cannot see – friction.
Why then, do we observe every day objects in motion slowing down and becoming motionless seemingly without an outside force?
It’s a force we sometimes cannot see – friction.

40. Objects on earth, unlike the frictionless space the moon travels through, are under the influence of friction.

41. Newton’s 1st Law and You Don’t let this be you. Wear seat belts.
Because of inertia, objects (including you) resist changes in their motion. When the car going 80 km/hour is stopped by the brick wall, your body keeps moving at 80 km/hour.

42. Gravity

43. Gravity
Force exerted by every object in the universe on every other object in the universe.

44. Force of Gravity Gravity is affected by mass and distance
Closer things exert more gravity on each other
Object with more mass exerts more gravity on an object of less mass

45. Gravity is a pulling force
It pulls things down towards the earth

46. Things fall because of gravity

47. Things always fall down

48. Gravity was discovered by a scientist called Isaac Newton

49. Stories say he discovered Gravity when an apple fell on his head

50. Gravity holds everything and everyone on the earth
Even in Australia

51. In Space, Gravity keeps the planets moving around the sun

52. 2nd Law
F = m x a

53. 2nd Law
The net force of an object is equal to the product of its mass and acceleration, or F=ma.

54. Circular motion
Circular motion (planetary motion) occurs because of two things.
1. An object, like a planet or the moon, is already moving with a certain speed in a particular direction
2. A force (gravity) acts on the object.

55. Gravity causes Earth to speed up (accelerate) in a straight line towards the Sun
Newton’s second law explains this effect - a net force causes an object with mass to accelerate

56. If Earth was not moving to begin with, the force of gravity would cause the Earth to accelerate until it collided with the Sun

57. Combination of Earth’s linear motion and the acceleration toward the Sun (sideways to the linear motion) leads to a curved path, orbit, around the Sun

58. Earth travels in an orbit around the Sun because of two forces

59. Moon travels in an orbit around Earth for the same reasons

60. If gravity stopped working, then Earth would move in a straight line at a constant rate

61. If there was no linear motion, then the Earth would fall into the Sun

62. Projectiles Projectiles – anything thrown or shot through the air
Projectiles have horizontal and vertical velocities and travel in a curved path

63. Projectiles Horizontal velocity is constant due to inertia
Vertical velocity increases due to gravity
Gravity exerts an unbalanced force and pulls the object down

65. Artificial satellites
If a projectile moves with enough linear speed so that its fall towards the ground exactly matches the curvature of the Earth, then the projectile will orbit the Earth