The Moon Features

27-2
The Moon

•Gravity is one sixth of
earth’s (divide your weight
by six)
•No atmosphere as a result
•Up to 127* C during day and
down to –173* C at night
* Slow rotation - due to "Sychronous
Tidal Lock with Earth

Multiple Choice

The Moon lacks and atmosphere because

• It never had time to form.

• There are no plants there to form one.

• There is not enough gravity to hold onto one.

Dropdown

The synchronous tidal lock that Earth has on the Moon causes it to ​

Select answer

slowly leading extremely ​

Select answer

days and extremely ​

Select answer

nights.

• Large, dark areas on the Moon are termed Maria meaning sea.
• Represent volcanic flows that occurred before 3 billion years ago.

They average 3km lower in elevation.

• Lighter colored, heavily cratered, areas are known as Highlands

are composed of regolith (broken rock)

Multiple Choice

The lowland areas of the moon are called Mare which is latin for

• lake

• valley

• sea

• ocean

Moon rock is similar to Earth rock

•Mare Basalt -- This sample
of mare basalt, ~3.7 billion
years old, was collected by
Apollo 17 astronauts. The
small holes in the sample are
vesicles, which formed by the
degassing of the lava as it
cooled. Courtesy of NASA

• Highland breccia --

collected by Apollo 16
astronauts. The breccia
contains basalt fragments
broken by a meteorite
impact and welded by the
heat and pressure of the
impact process. The rock
is 3.9 billion years old.
Courtesy of NASA.

Drag and Drop

The Mare rock of the moon were formed by ​

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flows, are full of ​

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and made of ​

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. The highlands rocks are ​

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welded together by the heat of ​

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Drag these tiles and drop them in the correct blank above

lava

vesicles

basalt

breccias

impacts

• Highlands Anorthosite --

Roughly 50% of the outer
highlands crust consists of
the rock anorthosite. It is a
plagioclase-rich rock
containing some pyroxene,
with or without olivine. The
sample shown here was
collected by Apollo 16
astronauts and is 4.4 billion
years old.

Multiple Choice

Highlands anorthosite rocks are mostly composed of the mineral

• quartz

• plagioclase

• pyroxene

• olivine

Giant Impact Hypothesis

•Is believed that a Mars-sized object hit the earth
early in the development of our solar system
•Material ejected from the glancing blow coalesced
into the Moon

Impact Craters

•Ejecta is material that fell
back to the surface after
impact
•Some craters have long
trails of ejecta known as
Rays

•Long, deep channels that run through
the maria are known as Rilles.
Hypotheses include: lava channels,
collapsed lava tubes, but most likely
caused by thermal erosion

Match

Match the following

• long deep channels form by expansion on the moon

• long trails of material caused by big impacts

• lots of these on the moon caused by impacts

• what the moon is NOT made of

• Most accepted theory of the formation of the moon is based on this idea

rilles

ejecta

craters

cheese

impact

• rilles

• ejecta

• craters

• cheese

• impact

Lunar Interior

• The highlands anorthosite is

dominated by the mineral
plagioclase feldspar.

• anorthosite crystallized early

in the moon's formation from
a global magma ocean.

• lighter plagioclase floated

upward to form the
anorthosite crust.

• The heavier minerals

olivine and pyroxene
sank toward the bottom of
the magma ocean to form
the moon's upper mantle.

•The Moon has minor
quakes
•The crust is thinner
on side facing earth
•The Moon may also
have a small iron core

Match

Match the layer of the Moon with the correct composition

• crust

• mantel

• core

• atmosphere

plagioclase

pyroxene and olivine

iron

none

• plagioclase

• pyroxene and olivine

• iron

• none