Moon Facts
I.
Inside and Out
A.
Core: _____________ km radius
1.
2.
3.
B.
C.
II.
The crust (~______ km) is represented by what’s called The highlands
The mantle is represented by The Maria
Physical Properties of the Moon
A.
The mass is ____________kg
1.
B.
C.
(______Earth)
Suggests that the Moon contains fewer heavy elements (such as iron) than Earth
Gravity is about ______
1.
III.
Solid inner core
Fluid outer core
Partial melt
m/s2
(______Earth)
An astronaut weighing 180 lb on Earth would weigh a mere 30 lb on the Moon
The diameter is ~______ miles
(______Earth)
How far is the moon?
A.
Radar and laser ranging yield more accurate distances than parallax (which uses the
Earth’s diameter)
1.
2.
B.
A radio telescope receives the echo after about a ______sec wait
How far is the moon?
a)
gives us a mean distance of ______________
Perigee and apogee
IV.
Synchronous Orbit
A.
Moon’s rotation
1.
B.
Moon’s revolution
1.
C.
orbit 360° around Earth = _________days
The two times are roughly equal
1.
D.
spin 360° on its axis = _________ days
So it keeps the _________facing _________ at all times
Far Side
1.
2.
Sometimes called the “___________________________” not true (it is lit during a
_________ moon)
3.
Composed almost entirely of ______________________ and __________________
V.
Lunar month – two timelines
A.
1.
_________days  time to orbit
1.
_________days  to complete phases (new moon to new moon)
B.
C.
Earth is moving in its curved orbit, too
1.
VI.
(>360° turn for us to see the full moon again)
Atmosphere
A.
B.
C.
The Moon has no protection against the harsh environment of interplanetary space
Why No Atmosphere?
1.
2.
Gravity comes from __________________
Air molecules need less speed to escape when there is less mass
a)
Moon’s escape speed is _________km/s
b)
Earth’s escape speed is _________km/s
VII. Temperature
A.
No atmosphere to regulate the temperature
B.
Noontime temperatures at the Moon’s equator can reach _________ K (_________
degrees F), well above the boiling point of water
C.
At night or in the shade, temperatures fall to about _________ K (_________degrees F),
well below water’s freezing point
Moon Origins
I.
These facts are accounted for
A.
The moon seems to be made of the same material as Earth's ______________________.
1.
2.
BUT it has little or no iron in it
Composed of material unlike the composition of the Earth as a whole.
B.
Is _________ in shape, like the other _____________ and not like an asteroid or comet
C.
It orbits in the same _____________ as _____________
D.
It is located in the _____________ _____________as the Earth (the ecliptic plane)
E.
Theory suggests that the Moon seems to have drifted away from the Earth over the
length of geologic history (____________________________________________________)
II.
Accretion Theory
A.
Accretion is the accumulation of small bits of matter in massive objects gravitationally
attracting more matter into a planetesimal
B.
Other names
1.
2.
3.
Condensation Theory
C.
The Moon and the Earth __________________________ together from the original
_____________ that formed the Solar System.
A.
Pros
a)
D.
Cons:
1.
2.
III.
Lots of material around in the early solar system to _____________
Why would the Earth and Moon have different ____________________ (ie iron is less)?
Moon is not on the same plane (tilted 5°)
Fission Theory
A.
B.
C.
Earth was _____________ so fast that it _____________the Moon
The present Pacific Ocean basin is the most popular site for it.
Pros:
1.
D.
Explains composition similarities
Cons:
1.
2.
3.
Moon should be orbiting along Earth's _____________; it's not.
Composition of Moon rocks _____________ to that of the Earth's surface.
Earth would have to have been spinning extremely fast.
IV.
Capture Theory
A.
B.
The Earth captures a moon adrift in space
Pros:
1.
C.
It would explain different __________________________
Cons:
1.
It's very unlikely - Moon’s capture would be difficult because its mass is not really that
much smaller than Earth (1/80th) and the object would be going really fast
2.
Still have similarities in composition
3.
Captured objects are not usually very _____________ and tend to be spinning
_____________ direction
V.
Impact Theory
A.
Today, many astronomers favor a hybrid of the capture + fission themes
B.
Postulates a collision by a large, _____________-sized object with a youthful and
_____________ Earth
C.
The matter dislodged from our planet then reassembled to form the Moon
D.
Pros:
1.
2.
3.
4.
E.
_____________ _____________ (but this is a whopper: Mars sized or bigger!)
Explains lack of _____________ & _____________ in Moon
Simulations confirm the possibility
Bonus: explains ____________________________________________________!
Cons:
1.
2.
The impactor needs more angular momentum than is now in the Earth-Moon system.
Why just one moon?
Terrain Notes
I.
Types of Terrain
A.
B.
C.
D.
E.
II.
Maria =
Highlands =
Craters =
Rays =
Rille =
Terrain
A.
The first observers to point their telescopes at the Moon noted large dark areas,
resembling (they thought) Earth’s oceans
B.
They also saw light-colored areas resembling the continents
C.
The light and dark surface features are also evident to the naked eye, creating the face of
the familiar “man in the moon”
III.
Features and names
A.
Maria =
1.
Latin names “mares” (English “_____________”) – maria is plural of _____________
2.
Examples: Mare _____________ (“Sea of Showers”), Mare _____________ (“Sea of
Clouds”), Mare _____________ (“Sea of Nectar”), etc.
B.
Highlands =
1.
Bear the name of mountain ranges or areas called “_____________”
2.
Examples: the _____________, the Carpathians, the Apennines, the _____________, the
land of fertility, the land of dryness, etc.
C.
Craters = _____________
1.
2.
IV.
Most are named after great _____________ or _____________,
Examples: Plato, _____________, Eratosthenes, and _____________ etc
Maria
A.
Dark regions, roughly circular, about _____% of the moon’s surface
B.
Extensive flat areas that resulted from lava flows during a much earlier period of the
Moon’s evolution
C.
Largest are ~____ miles
1.
2.
D.
V.
Mare Frigoris (“sea of cold”) _____________ km
Mare Imbrium (“sea of showers”)
_____________ km
Most face _____________
Lunar Highlands
A.
B.
lighter areas elevated several kilometers _____________the maria
Contain most of the _____________
VI.
Composition of moon rocks
A.
Highlands:
1.
rocks rich in _____________, making them _____________ in color and
low_____________
2.
Dating indicates ages of _____________ billion years
B.
Maria:
1.
its _____________ matter contains more iron, giving it a _____________color and
greater _____________
2.
Dating indicates from _____________billion years
C.
Craters
1.
Most craters apparently formed eons ago primarily as the result of _____________
impact
2.
Most are on the ________ side and in the _____________
3.
However the _____________ are mostly on the _____________ side
a)
The largest (2500 km), deepest, oldest crater in solar system is on moon’s far side
– called the Aitken Basin
a)
The smallest are microscopic
D.
Crater Rays
2.
3.
Formed by _____________ (from impact)
Most prominent rays come from _____________
a)
P.S. Tycho is not the South pole and it’s not the biggest crater
Tides
I.
Specially named tides
A.
Tides happen 4 times per day (____ high, ____ low) due to earth _________ on its
_________
B.
Specially named tides happen when the _________ align in certain ways (next slide)
C.
1.
2.
Tidal range is __________________
Not related to seasons
1.
Tidal range is _________
D.
II.
How do we get Special Tides?
A.
1.
2.
3.
E/M/S are all _________
2 x per month
1.
2.
3.
E/M/S _________
2 x per month
B.
See the moon from Earth
I.
Size
A.
How big is the Sun compared the moon?
1.
2.
3.
II.
Distance
A.
How far is the Sun compared the moon
1.
2.
3.
III.
Diameter of the Sun =
Diameter of the Moon =
How much bigger is the sun? (ratio sun/moon)
Distance to the Sun =
Distance to the Moon =
How much farther is the sun? (ratio sun/moon)
Eclipse - The 400:400 ratio is what gives us eclipses, but…
A.
The moon’s distance is constantly _________
B.
When the moon is closer to _________ (closest point), it would cover the sun
(a _________ _________) a full moon at perigee is called a ” __________________”
C.
When the moon is further (_________ = farthest point), it appears _________. For
example, we can still see the sun during an _________ eclipse
D.
When the moon is near the _________, the ground & horizon make the moon appear
relatively _________
IV.
Shadows & Light
A.
B.
Only _________ faces us at any time
Full moon
1.
2.
3.
C.
New Moon
1.
2.
3.
D.
E.
F.
G.
H.
I.
J.
Sun/Moon are on _________ sides
_________ side faces us
Sun/Moon on _________ side
_________side faces away
Waxing – getting _________
Waning – getting _________
Crescent –
Gibbous –
Terminator –
Lunar limb – the edge of the circle of the moon
Cusps – where the limbs meet (~the _________)
V.
Lunar Phases
A.
New moon
B.
Waxing Crescent moon
C.
1st Quarter moon
D.
Waxing Gibbous phase
E.
Full moon
F.
Waning Gibbous phase
G.
3rd Quarter moon
H.
Waning Crescent Moon
I.
New Moon