Origin of the MoonOrigin of the Moon • Approx. 4.6 billion years ago Earth collided with an Approx. 4.6 billion years ago Earth collided with an

object the size of Mars. It is believed that Earth had a object the size of Mars. It is believed that Earth had a hard crust, but the inside was molten rock (still liquid). hard crust, but the inside was molten rock (still liquid). This collision caused a large mass of liquid rock to be This collision caused a large mass of liquid rock to be thrown into space. It cooled and hardened into what thrown into space. It cooled and hardened into what we know as the moon. (THEORY – NOT FACT)we know as the moon. (THEORY – NOT FACT)

• Since the moon has no atmosphere to protect it from Since the moon has no atmosphere to protect it from debris floating in space, its surface is covered with debris floating in space, its surface is covered with impact cratersimpact craters

50 miles

1.Movement of the Moon1.Movement of the Moon

a. Takes 27 1/3 days to rotate on its axis as well as revolve around the earth We only see one side of the moon

b. The move rotates and revolves counterclockwise Rises in the east and sets in the west (JUST LIKE THE SUN)

c. The time at which the moon rises is 50 minutes later each day as a result of its revolution around the Earth Why moon is out during the day

d. Since the orbit is elliptical, the moon is at times closest to Earth (perigee), and at other times farthest from Earth (apogee)

Perigee

356,410 km

Apogee

406,700 km

2. PHASES OF THE MOON2. PHASES OF THE MOONa. Caused by the position of

the moon relative to the sun and the earth

b. When moon appears to get larger it is said to be waxing (gets lighter from right to left)

c. When moon appears to get smaller it is said to be waning (Gets darker from right to left)

……PHASESPHASES

d. The time it takes the moon to go from one new moon phase to the next new moon phase is called a lunar month. This takes 29½ days

e. Takes about 4 days for the moon to go from phase to phase

SUNL

IGHT

SUNL

IGHT

Blue Moon…

A blue moon is when there are 2 full moons in one month. The moon isn’t actually blue though!

3. Eclipses

a. When either sun is blocked out by shadow of the moon, or moon is blocked out by shadow of the earth

b. Two parts to shadow1. Umbra- Darkest part of shadow2. Preumbra- Lighter part of the shadow

3c. Types of Eclipses

1. Lunar Eclipse- Can only occur when moon is full, the earth is casting shadow on moon (happens twice a year)

3c. Types of Eclipses

2. Solar Eclipse- Can only occur when moon is new, the moon is blocking out the sun (much more rare)

3. Eclipses

d. Eclipses do not occur every month because the moons orbit and earths orbit are not in same elliptical

4. TIDES4. TIDES

a. The rising and falling of the levels of water caused by the pull of the moon’s (and to some extent the sun’s) gravity

b. Daily Tides1. On average, many locations receive two high

and two low tides each day (approx. six hours apart)

4. Tides

c. Monthly tides1. Spring tide- When

there is a full or new moon (Extremely High Tides)

2. Neap tide- When the moon is in 1st or last quarter (Extermely low tides)

Benedictine Abbey – Bay of Fundy (Nova Scotia, Canada) – founded in 708, highest tidal range in the world!

Same Abbey @ High Tide –

Man-made causeway added in 1992

Low Tide and High Tide @ Hilton Head, SC