Download Earth`s Moon!

List all the characteristics you
can think of about the moon?
Ch. 28
Formation of the Moon
 Giant Impact Hypothesis
 The giant impact hypothesis states that the
formation of the moon began when a large object
collided with Earth more than 4 billion years ago.
Formation of the Moon
 The collision ejected chunks of Earth’s mantle into orbit
around Earth. The debris eventually clumped together to
form the moon.
 This hypothesis explains when moon rocks share many of
the chemical characteristics of Earth’s mantle.
Formation of the Moon
 The debris eventually orbited the Earth and became
our moon.
Formation of the Moon
The Moon
 satellite - a natural or artificial body that revolves
around planet.
 moon - a body that revolves around a planet and
that has less mass than the planet does.
 Seven of the planets in our solar system have
natural satellites, or moons. Our moon is Earth’s
satellite.
Natural or Artificial?
The Lunar Surface
 Any feature on the moon is referred to as LUNAR
 mare - large, dark area of basalt on the moon
 The light patches seen on the moon’s surface are
called anorthosites. The darker areas are called
maria.
 Maria are plains of dark, solidified lava which
formed more than 3 billion years ago when lava
slowly filled basins that were created by massive
asteroids.
Lunar Surface
 crater a bowl-shaped depression that forms on the
surface of an object when a falling body strikes the
object’s surface or when an explosion occurs
 Remember our Impact crater lab??
Rilles and Ridges
 Rilles are long, deep channels that run through the maria.
Rilles are thought to be leftover lava channels from the
formation of the maria.
 The moon’s surface also has several ridges, which are long,
narrow elevations of rock that rise out of the surface and
criss-cross the maria.
Name two features of the
moon???
Name two features of the
moon????
 The moon’s features include maria, craters, ridges, and
rilles.
Regolith
 The moon’s surface is very susceptible to meteorite
hits because the moon has no atmosphere for
protection.
 Over billions of years, these meteorites crushed
much of the rock on the moon’s surface into a layer
of dust and small fragments called regolith.
 1 to 6 meters deep
Lunar Rocks
 Lunar rocks are igneous, and most rocks near the
surface are composed mainly of oxygen and silicon.
 Rocks from the maria are fine-grained basalts and
contain titanium, magnesium, and iron.
 Breccia is found in both maria and the highlands.
Lunar breccia formed when meteorites struck the
moon.
The Moon’s Layers
 Like, Earth, the moon has three compositional layers:
the crust, the mantle, and the core.
 The interior of the moon is less dense than the interior
of earth.
Differentiation of the Moon
 Early in its history, the lunar surface was covered
by an ocean of molten rock.
 Over time, the densest
materials moved toward
the center of the moon and
formed a small core.
 The least dense materials
formed an outer crust.
Moon’s Crust
 The side of the moon that faces Earth is called the
near side, while the side of the moon that faces
away from Earth is called the far side.
 The crust on the near side is about 60 km thick.
The crust on the far side is up to 100 km thick.
 The difference in thickness was caused by the pull
of Earth’s gravity during the formation of the
moon.
The Moon’s Mantle and Core
 Beneath the crust is the moon’s mantle. The
mantle is thought to be made of rock that is rich in
silica, magnesium, and iron.
 Scientists think that the moon has a small iron
core that has a radius of less than 700 km.
 Neither completely solid or completely liquid
Lava Flows on the Moon
 After impacts on the moon’s surface formed deep
basins, lava flowed out of cracks, or fissures, in the
lunar crust.
 This lava flooded the crater basins to form maria.
 Because of the uneven thickness of the moon’s
crust, more maria formed on the near side of the
moon than on the far side.
Review Quiz:
What is the name of the hypothesis that suggests
how Earth’s moon was formed?
1.

Great Impact Hypothesis
2. How many planets in our solar system have moons?
 seven
3. The darker areas on the lunar surface are called
what?

Maria