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Earth Science
Chapters 10 & 11
Chapter 10- Earth & Its Moon
 Lesson 1- Earth’s Seasons
Objective- In this lesson, we will learn how
the Tilt (position) of the Earth’s Axis will
cause seasons
Earth’s Tilted Axis
 Earth rotates
constantly on its axis
It takes almost 24 hours
for Earth to make a
complete rotation on its
axis (equal to one day)
 As Earth spins,
different parts of it
face and turn away
from the Sun.
This creates day and
night
 As Earth spins on its axis, it also revolves around
the Sun.
 One full trip around the Sun is a Revolution
It takes about 365 days, or 1 yr.
 Earth’s orbit is in an ellipse shape
 Because of Earth’s tilted axis, some areas
experience severe seasons, while others (near
equator) do not.
Solstices
 There are two solstices
throughout the year.
 Winter Solstice- December 21 or
22
First day of Winter
Least amount of daylight all year
 Summer Solstice- June 21 or 22
Beginning of summer in N.
Hemisphere
Longest amount of daylight all year
Equinoxes- Periods of daylight are equal
 Autumnal EquinoxSeptember 22 or 23
First day of Fall
 Vernal Equinox
March 20 or 21
First day of Spring
Seasons
 All places on Earth
have four seasons.
 Places near the Poles
have lower average
temperatures than
places near the
Equator
This is caused by
amount of sunlight the
area receives
Lesson 2- Earth’s Moon
The Moon
• The moon is a natural
satellite that revolves
around the Earth
• It is ¼ the size of
Earth
• Mass is 80 times
lighter than Earth’s
• It has less gravity
than Earth
Viewing the Moon
 The moon seems so large because it is closest
to Earth than any other object in space. ( it’s
actually smaller than Earth)
 Moon doesn’t produce any light.
Sun reflects light off its surface
 Moon revolves around Earth, while it rotates on
an axis.
Takes 27 and 1/3 days to revolve, and rotate once
around Earth.
Same side of the Moon ALWAYS faces the Earth.
Phases of the Moon
 One side of the Moon
(half) is always lit by
the Sun.
The different shapes
created by the visible
light are Moon Phases
 Different parts of the
Moon’s lit side are
visible on Earth
Takes about one month
to complete one Moon
phase cycle.
Phases of the Moon
 New Moon- the Moon is
between Earth and the
Sun. Because its lighted
side is facing away from
Earth, the Moon appears
dark when viewed from
Earth.
 Waxing Crescentappears after the new
Moon phase. The sunlit
portion is increasing, but
less than half.
 The first quarter and
third quarter moons (both
often called a "half
moon"), happen when the
moon is at a 90 degree
angle with respect to the
Earth and Sun. So we are
seeing exactly half of the
moon illuminated and half
in shadow.
 Waxing Gibbous- After the
first quarter, the sunlit
portion is still increasing,
but now it is more than
half.
 At a full moon, the Earth,
Moon, and Sun are in
approximate alignment,
just as the new moon, but
the moon is on the
opposite side of the earth,
so the entire sunlit part of
the moon is facing us.
The shadowed portion is
entirely hidden from view.

http://www.moonconnection.com/moon_phases_calenda
r.phtml
 Waning Gibbous- After
the full moon (maximum
illumination), the light
continually decreases.
 Following the third
quarter is the waning
crescent, which
decreases until the light is
completely gone -- a new
moon.
Eclipses
An Eclipse occurs when one object passes
into the shadow of another object
In order for one to occur, Earth, Sun and
the Moon must all be aligned
During a Total Eclipse, two types of
shadows form
Umbra- smaller, darker area, in Penumbra
Penumbra- Larger, lighter area
Solar Eclipse
 Occurs when the
moon passes
between the Sun and
Earth
 Moon casts a shadow
on Earth
During the Day
Moon blocks out the
sunlight.
Sun appears Black
Lunar Eclipse
 Takes place when the
Earth passes directly
between the Sun and
Moon.
 Moon moves into
Earth’s shadow
Occurs at night/dusk
Moon appears to be a
reddish color
Chapter 11- Exploring Space
 Lesson 1- The Solar
System
The Sun and Its Neighbors
 The Sun and the bodies that
orbit around it make up the
solar system.
 Sun is largest in solar system
 Earth is one of eight planets in
the solar system.
 Scientists believe that the solar
system is about 4.6 billion
years old.
 The strong gravitational force
of the Sun holds all other
objects in their orbits.
Moons
 There are about 140
moons in the solar
system.
 Some moons have
their own
atmosphere, unlike
Earth’s moon.
 All are held in orbit by
the gravity of their
planet.
Asteroids
 A small rocky object
that orbits the Sun.
 Most are in a band
between Jupiter and
Mars, called the
asteroid belt.
 There are many
theories about how
asteroids formed.
Comets
Small bodies made of dust, ice and frozen
gases.
Orbit the Sun in long elliptical orbits.
A Coma is a glowing region formed from
gases and dust of frozen solids.
Tail of a comet always faces away from
the Sun.
Famous Comets
Halley’s Comet- shortperiod comet that orbits
the Sun about every 76
years.
Visible from Earth
again in 2061
Hale-Bopp CometLong-period comet,
takes about 2500 years
to orbit the Sun.
Meteors and Meteorites
 Meteors are small chunks of matter that enter
into Earth’s atmosphere
Most burn up in the atmosphere, never striking Earth
 When many are visible at once, this is called a
Meteor shower
 A meteor that does strike Earth is called a
Meteorite
When large ones strike Earth, they form impact craters
Lesson 2- What are the Planets Like?
The Inner Planets
 Inner Planets are
rocky and small
 There are 4 inner
planets
Mercury- smallest and
closest to the Sun.
 Side facing the Sun is
very hot, facing away
from the sun is very
cold.
 Many craters on the
surface
Venus
 Venus- is the second
planet from the Sun
Thick atmosphere of
clouds made of sulfuric
acid.
Hot temperatures on
surface
Extreme atmospheric
pressure
Earth
 Earth- 3rd planet from
the Sun
Only planet known to
have liquid water
Atmosphere and
oceans make it the only
planet in solar system
known to support life
Mars
 Mars- 4th planet from the
Sun
Known as the Red
Planet
Smaller than Earth but
same amount of land
area.
Home to largest volcano
in the solar system
Planet most like Earth
Most explored planet,
Mars Expedition Rovers
Outer Planets
There are four outer planets
Most are huge and made of gases
They have many moons and one or more
rings.
Pluto (dwarf planet) is the only exception
Jupiter
 5th planet from the Sun,
and one of the brightest
objects in the sky
 Biggest and most
massive planet in the
solar system
 Famous for its Great Red
Spot, a gigantic storm
system
 More than 60 moons.
Saturn
 6th planet from the
Sun
 Best known for its
rings, mostly made of
ice particles
 Least dense of all
planets
Holds more than 30
moons in its orbit
Uranus
 7th planet from the
Sun
 Axis is tilted so much,
it looks like it on its
side
 Consists mostly of
gases
 11 rings, and 27
moons
 High amount of
methane give it the
greenish color
Neptune
 8th planet from the
Sun
 Has 11 moons,
Largest moon is
Triton
Neptune is getting
closer to Triton, and will
probably collide in the
next 100 million yrs.
 Coldest surface in the
solar system
Pluto
 Farthest from the Sun
 Recently (2006)
discovered as a
Dwarf Planet
 Very cold
 Has one moon called
Charon
 Unlike other outer
planets:
Small, icy, rocky
Exploring Space
 Optical telescopes are used to
explore solar system
 The space shuttle takes equipment
and people into space
 Space stations stay in space for
long periods of time, astronauts can
live, sleep and conduct experiments
 Space Probe- spacecraft that
carries special instruments into
space
 launched into Earth’s upper
atmosphere
 Mars Rover- explored Mars, taking
pictures and samples
Lesson 3- What Are Stars Like?
Earth’s Star: the Sun
Star- large sphere of glowing gases
Defined by its size and temperature
Sun is a yellow star made mostly of
hydrogen and helium
A light-year (Ly)- used to measure outside
of the solar system
Distance light travels in about 1 yr.
Magnitude- brightness of a star
Stars closer to Earth appear brighter
Constellations- arranged patterns of stars
Big Dipper
A Star is Born
Stars begin as rotating clouds of gas
called nebulas
Cloud rotates faster and forms first stage
to a star called a protostar
Main Sequence star- continues to release
energy, w/ nuclear reactions
Hottest, brightest stars are blue or white in color
Medium sized are yellow or orange
Dimmest and coolest are Red.
Sun is a medium star, halfway through its
life cycle
Red Giant Phase- after a main sequence
 White Dwarf phase
a. Medium sized stars move here
b. Beginning of dying stage, starts to
run out of “fuel”
c. Becomes a black dwarf- star that
gives off NO LIGHT
 Supernova
a. A very massive star that will explode
from its center.
o Larger remnants will become a Black hole
i. powerful gravitational pull, and
collapses onto itself
o Smaller masses will become a Neutron
star
i. dense, rapidly spinning star
Galaxies
Enormous system of gases, dust and stars
held together by gravity
 Most stars have 2 main partsBulge
Halo
Milky Way
 Galaxy of our solar system
Spiral Galaxy
More than 200 billion stars
Types of Galaxies
Spiral Galaxy- has a bulge, disk and halo,
and arms that extend
Elliptical Galaxy Shaped like a flattened ball
 Brighter in the center
Irregular Galaxies
 no real shape or structure
 large regions of hydrogen gas and hot star