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UNIT 4: ASTRONOMY

PACKET 5: FROM EARTH’S PERSPECTIVE
When you change
the way you look at
things, the things you
look at change
P.S. I’m Theodore
EARTH SCIENCE
MS. GILL
NOTE PACKET #5
NAME:___________________CLASS:_________ DATE: ______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Astronomy from Earth’s Perspective:
Before the invention of technology that enable humans to leave earth’s perspective,
astronomers relied solely on their observations of the heavens to make inferences about
earth’s motions.
Models of the Solar System
 Based upon observations of the apparent motion of
celestial objects.
 Before our current understanding that the planets
revolve around the sun, people actually believe that
the sun and other planets revolved around earth.
___________________________
– Earth is the center of the solar
system, and all objects revolve around
it.
-Used epicycles (small sub-orbits) to
explain retrograde (backward) motion
of planets
___________________________
– The Sun is at the center, and the
planets revolve around it
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Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Coordinates in the Sky…
On earth we use latitude and longitude to locate places. In astronomy we use
_______________ and __________________.
Altitude is the angle above the horizon in degrees. (Horizon: imaginary boundary between
the sky and the ground)
The highest angle of altitude is ______ and that is the point directly over the observers
head. The 90° point is called the ________________.
Azimuth is direction broken down into degrees from ________ to _______
Altitude and azimuth together form a coordinate grid for locating objects in the sky.
We draw this grid on a model of the sky on a dome called a ___________________.
The Celestial Meridian is the imagine line that is drawn from the North to the South on a
celestial sphere. When a celestial object crosses the meridian it is at its highest point on
its daily path.
Earth’s Shape
Rather than a perfect sphere Earth is an
_____________________________________
Meaning that the equatorial circumference is just
slightly bigger than the polar circumference.
(bulges at the equator) This difference is small
and can not be seen with the naked eye.
Proof that the earth is round:
-Ships appear to sink GRADUALLY below the
horizon as they travel away from observer
-Polaris (North Star) changes altitude (angle
measured in degrees above earth’s surface)
directly with your latitude
-Lunar Eclipses - Earth’s shadow on the moon
-Satellite Imagery (pictures) – absolute proof
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Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Earth’s Rotation:
Celestial observations
___________________________: any object in space (outside of earth’s
atmosphere) examples: Moon, planet, stars, sun
The apparent daily motion of celestial objects (like stars) have enabled scientist to
create theories about earth’s motions: _________________ & ________________
Rotation:
The apparent daily motions of the
celestial objects in our sky are due to
Earth’s Rotation or spin on its axis
How long is one rotation? ________
Rotation is responsible for:
-Day and Night (Local time)
-Rising and Setting of our Sun & Moon
-Movement of stars through the sky
Rotational Facts
-Earth’s axis is tilted 23.5 degrees from the line perpendicular to earth’s orbit. Earth’s
axis is always tilted in the same direction, this is called ____________________.
-Currently Earth’s axis points directly to the star ______________ (the North Star).
___________– the imaginary line through Earth from the North Pole to the South Pole
The earth rotates _________________ when looking from down at the North Pole
from ______ to __________ when looking at a side view of earth
How many degrees per hour does the earth rotate? Show calculation:
________ degrees per hour
________ degrees per day
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Evidence of Earth’s Rotation
1. ____________________________________
2. ___________________________________
Foucault’s Pendulum
As the pendulum swings back and
forth, the Earth rotates underneath
it so that the direction of the
pendulum's swing appears to change.
Since there is NO force that makes
pendulum rotate – must be earth that
is rotating!!!
The ground moves under the freely
swinging pendulum.
The Pendulum appears to move but is
actually swing in the same initial
direction
Coriolis Effect
A projectile fired northward from
the equator appears to veer
eastward because it retains the
eastward speed of the equator,
which is greater than the eastward
speeds north or south of the
equator.
Because of the Coriolis effect,
projectiles and currents of air and
water veer to the right in the
northern hemisphere, and to the
left in the southern hemisphere
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Effects of Earth’s Rotation:
1._______________________________________
2._______________________________________
3. _______________________________________
Determining Time of Day: Since the earth rotates at a predictable rate (15 °per
hour) we can easily determine the time of day when looking at an aerial image of earth
on the equinoxes. Start by indicating the direction of rotation. Then label your
diagram with 12 AM, 12 PM, 6 AM and 6 PM. Draw in the lines of longitude, all
locations on this line will have the same time.
Remember
12pm (noon)
will be in the middle of the day
or lit portion of the earth.
12 am (midnight)
will be in the middle of the night,
or dark side of the earth.
Apparent Daily Motion
An apparent motion is a motion an object appears
to make, it can be real or an illusion.
Celestial objects appear to move in the sky.
This is due to the __________________________
Celestial Objects appear to move ______________,
because Earth rotates 360° in ______ hours.
Sun:
Rotation is responsible for the illusion that the sun rises and sets each day. The sun’s path, from sunrise
to sunset has a shape of an arc. This path changes in both position and length with the seasons.
Moon:
The moon also follow the daily east to west apparent motion. However it appears to rise about 50
minutes later each day.
Polaris:
Our North Star is the only object in our sky that show NO apparent motion. This is due to the fact that
it is directly in line with our axis of Rotation
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Stars:
The apparent daily motions of stars changes when the observer’s
_________________ on earth changes.
-Therefore, at the poles (90° N or S) stars do not rise or set
but at the equator (0° ) all stars rise and set.
-At 41° N (New York state) some stars, like the sun appear to
rise in the east and set in the west making an arc across the
celestial sphere. Other stars such as ones part of circumpolar
constellations never set but instead trace out giant circles daily
around the poles with Polaris in the center.
-Notice how the _____________ shows no apparent motion. It
is the only star that does not move.
-Using a time-lapse camera we can document this phenomenon.
We call these images _________________
-When you quickly glance at the sky the stars appear stationary
(not moving). Why do they have this pattern?
______________________________________________
How many degrees did the stars move from diagram 1 to diagram 2?
____________
How can you find Polaris?
_________________________________________________________________
What hemisphere must you be in if you can see these constellations? Why?
_________________________________________________________________
What direction must you be looking?
______________________________
Do the stars appear to move clockwise or counterclockwise?
___________________
What causes them to appear to move at all?
___________________________________________________________ Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Revolution:
________________________________________________________________
________________________________________________________________
________________________________________________________________
The apparent yearly change in position of all celestial objects is due to the Earth’s
Revolution around the sun.
Facts about Revolution
How long is on earth revolution?
Period of revolution: the length of time for one orbit around the sun = 1 year
How many days are in 1 year ? ________
To account for the .26, Every leap year we add February 29 to our calendar to account
for the four quarter days we accumulated over the last four years.
How many degrees does the earth travel in its orbit around the sun in one day?
_____________ Show calculation below:
Revolution is responsible for:
-Sun’s positional path across the sky
-Angle of Insolation
-Seasons (combined with Earth’s tilt)
-Changing Constellations through out the year
-Rising and setting of the moon later and later each day
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Constellations:
Constellations are groupings of stars that make an imaginary image
in the night sky. They have been named after mythological
characters, people, animals and objects. In different parts of the
world, people have made up different shapes out of the same groups
of bright stars. It is like a game of connecting the dots. In the past
constellations became useful for navigating at night and for keeping
track of the seasons. Stars in constellations are often very far from
one another but we see them in the same direction in the sky
Evidence of Earth’s Revolution around the Sun
-Seasonal Constellations: Because of the Sun’s annual motion, some constellations are visible at
night only during certain seasons.
-Constellations are visible when the dark side of Earth (away from sun) faces toward the
constellation.
-The 13 constellations the sun appears to travel through during the year
Position
A
Season
Constellations Visible
B
C
D
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Constellations:
Directions:
1) Draw and label the daily positions
of the big dipper due to rotation.
2)Draw label the positions of the big
dipper during the yearly cycle due to
revolution.
1) Daily position of the big dipper:
2) Yearly position of the big dipper:
Regents Questions:
3) Which observation provides the best evidence that Earth revolves around the Sun?
(1)The constellation Orion is only visible in the night sky for part of the year.
(2)The North Star, Polaris, is located above the North Pole for the entire year.
(3)The sun appears to move across Earth’s sky at a rate of 15○/hr.
(4)The Coriolis effect causes Northern Hemisphere winds to curve to the right.
4) Which object is closest to Earth?
(1)The Sun
(2)Venus
(3)the moon
(4)Mars
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Seasons:
Name the four seasons and their starting dates:
Season
Starting date
How many days are in each season on average? _______
What causes the seasons?
_________________________________________________
_________________________________________________
_________________________________________________
As earth revolves around the sun– the tilt of Earth’s axis does not change producing a
cyclical change of seasons…. Earth’s axis is always tilted __________.
Label the seasons on the
aerial views of earth…
Note the position of the
shadow
Label perihelion and
aphelion…
Is distance important to seasonal change? ________ because earth’s orbit is a
___________________________________
Earth is farthest away from the sun on ________ this is called _____________
Earth is closest on to the sun on ________ this is called _______________
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
What changes do we observe during seasons in NY?
1. ________________________ changes
-The sun is highest on June 21 (summer)
-The sun is lowest on Dec. 21 (winter
- _________________________ at our latitude.
2. ___________________________________ also change with the season.
-On the equinoxes, the sun always rise due east and sets due west.
-The rises and sets South of east and west in __________ and _____________.
-The Sun rises and sets North of East and West in ___________ and ____________.
3. __________________________( Duration of Insolation) changes with the season.
- ___________ hours of day light: Shortest on Winter Solstice, Dec. 21
- ___________ hours of day light: Longest on Summer Solstice, June 21
-12 hours on Equinox for all locations on Earth
The tilt of the Earth on its axis is also responsible for the day and night length
EQUINOX (MEANS EQUAL NIGHTS) =12 HOURS OF DAY AND 12 HOURS OF NIGHT
Important facts about the solstices and equinoxes in the Northern Hemisphere
Summer Solstice
1.June 21, longest day of the
year.
2.Sun at highest altitude at
noon.
3.24 hrs of daylight at North
Pole.
4.Direct sun ray at 23.5°
north latitude.
5.Sun rise – NE, Sun set NW
Winter Solstice
1.Dec. 21, shortest day of
the year.
2.Sun at lowest altitude at
noon.
3.24 hrs. of darkness at
North Pole.
4.Direct sun ray at 23.5°
south latitude.
5.Sun rise – SE , Sun set –
SW
Both Equinoxes
1.Sept. 21 and March 21.
2. Equal day/night 12 hrs of
daylight, 12 hrs of night.
3.Direct sun ray at Equator.
4.Sun rise – E, Sun set – W.
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Apparent Solar Motion
Rotation cause Sun’s apparent daily path from sunrise to sunset has the shape of an arc
moving l5° per hour. However, the sun’s arc changes both its position and its length with
the seasons due to the earth’s Revolution.
The sun appears to move across the sky, like all celestial objects due to earth’s rotation.
But sun’s apparent path in the sky varies by _______________ and _______________.
How does the location of the sun change through
out the year?
-No matter where you are on the globe, on the
equinoxes, the sun will always rise due east and set due
west. The path depends on your latitude.
-Changes in the altitude of the path and horizon
position of sunrise and sunset are due to
_______________________________
Date
Equinoxes
(Spring/ Fall)
Summer
Solstice
Winter
Solstice
Sun Rise
Sun Set
Altitude of Solar Noon is…
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Directions:
On the diagrams
below, draw and
label the path of
the sun for each
location during
the equinox, the
spring solstice
and the winter
solstice.
Long Island, New York
Latitude = approximately 40°
Summer max altitude of noon sun is ____
Winter is ______
Spring/Autumn: _______
A location along the Equator
Latitude = 0
Summer max altitude of noon sun is ____
Winter is ______
Spring/Autumn: _______
A location along the arctic circle
Latitude = approximately 66.5°
Summer max altitude of noon sun is ____
Winter is ______
Spring/Autumn: _______
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Your shadow!
-In NY, the noon sun will always be in the South
Sky! So which way will your shadow fall?
________
-Your shadow always changes with the altitude of
the sun and time of day!
-The length and direction of a shadow depends on
the ____________________ and the observers
____________________. Both variables effect
the sun’s altitude and the angle of insolation.
-Your shadow will always be opposite of the sun, if
the sun is just rising in the east, your shadow will
fall west. If the sun is high in altitude, your
shadow is small, when it is low in altitude your
shadow is long.
-Five different shadows, A', B', C', D', and E', are
cast on a certain day by the post when the Sun is
in positions A, B, C, D, and E, respectively.
Review Questions:
1) If Earth’s axis were tilted less than 23.5○, which seasonal average temperature
change would occur in New York State?____________________________________
2) Which position of Earth represents the first day of summer in the Northern
Hemisphere? _________
3) How many degrees will the Sun’s vertical rays shift on Earth’s surface as Earth
travels from position C to position D? ________________________
4) What causes the seasons?
__________________________________________________________________
__________________________________________________________________
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Insolation:
a. “IN”-coming “SOL”-ar radi-“ATION”
b. The HIGHER the Sun is in the sky, the stronger (more intense) the sunlight is.
c. Places near the EQUATOR receive the most intense insolation.
d. At places near the POLES, the Sun never rises high in the sky, so the sunlight is always weak. The
Polar Regions receive the least intense insolation.
e. During the summer months, the duration, angle, and intensity of insolation are HIGHEST.
f. Day=hot; Night= cold (no insolation)
g. Summer=hot; Winter = cold
Factors that Affect the
Intensity and Duration of Insolation absorbed by Earth’s Surface:
1) Earth’s Shape causes of Insolation to hit at an Angle:
-Due to Earth’s Spherical Shape, the parallel rays from the sun
strike different parts of the Earth’s surface at different angles.
-Near the poles where to angle of insolation is smaller,
the energy spreads out over a larger area. As a result,
the intensity of insolation is much less than that in
regions with a higher angle of isolation.
See diagram to the right 
a) The DIRECT RAY: refers to the ray that is perpendicular to earth surface (highest angle of insolation
possible). This is where the altitude of the sun is 90° (at the zenith) and therefore the angle of insolation is
also 90° degrees. The Direct ray is where the greatest intensity of insolation is found because the rays are
CONCENTRATED on a smaller area so the temperature INCREASES. This always occurs at solar noon, but
the latitude it occurs at depends on the season.
b) The Direct Ray Shifts depending on the Season:
-Since earth is spherical, tilted and revolving around the sun, there is just one line of latitude that receives
direct insolation each day. This occurs at the latitude where the sun is at its zenith which varies based on
the season due to Earth’s revolution and tilt.
During the Spring and Fall Equinoxes – the direct ray is at the equator,
since neither the Northern or Southern Hemisphere is tilted toward the sun,
Note that duration of insolation equals 12 HOURS at every location on earth.
Solstice – the date when the direct ray is at a maximum distance from the equator.
-During the Summer Solstice, the Northern Hemisphere is tilted toward the Sun,
and the direct ray hits the 23.5° N, which is called the Tropic of Cancer.
-During the Winter Solstice, the Southern Hemisphere is tilted toward the Sun,
and the direct ray hits 23.5° S, called the Tropic of Capricorn.
This is why the hottest parts of the world are between the Tropics, these are the only areas that
receive DIRECT insolation!
Question: Does the Direct Ray ever hit New York? _____________________
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
2) Angle of Insolation:
As the angle of Insolation increases, the intensity of insolation increases (it’s hotter).
The intensity of Insolation increases as the as the sun’s altitude INCREASES!
Why? When the Sun is higher in the sky, the rays are CONCENTRATED on a smaller area so the
temperature INCREASES.
ANGLE OF INSOLATION = ALTITUDE OF THE SUN.
Remember that the altitude of the SUN depends on three factors
A) Latitude
B) Time of day
C) Season
A) Latitude’s effect on Angle of Insolation
Lower latitudes like the Equator, have higher angles of insolation and therefore a higher intensity.
Remember this is due to Earth’s spherical shape, cause only one area to receive direct insolation. Thus
it’s hotter at the Equator! Why? Lower latitudes like the Equator, have higher angles of insolation and
therefore a higher intensity.
B) Variation of the Angle of Insolation based on the Time of Day:
The intensity of the sun and the angle of insolation are greatest around noon when the sun is highest in
the sky. The intensity and angle of insolation are weakest at sunrise and sunset when the sun is low in
the sky. Thus it’s hottest in the middle of the day, coldest at night!
However, the Maximum temperatures occurs around 2PM , which is after the maximum insolation. The
Minimum temperatures occur after the Sun rises. What causes this temperature lag?
Even though the angle of insolation decreases after noon, the Earth is still absorbing more energy
than it’s radiating back into space so it continues to warm up. Likewise, When the Sun first rises the
Earth is reradiating heat into space, so the temperature continues to DROP A LITTLE, even though
the Sun is out. During the hottest and coolest time so of the day, the Earth is said to be in HEAT
BALANCE.
3) Duration of Insolation:
At any given location, the LONGER the Sun is shining, the HIGHER the temperature.
Duration depends on the SEASON and LATITUDE.
Ex: In the summer, the sun has a higher angle, which means it has a longer path to travel, which
means a greater duration.
Ex: Likewise, lower latitudes have experience longer days due to the tilt of our axis.
Latitudes affect on Duration of Insolation
-Due to Earth’s tilt, spherical shape, rotation and revolution, the apparent path of the sun is different
for different locations, through out the year.
-Equator always receives 12 hours of sunlight everyday, since it is never tilted toward or away from
the sun, because it wraps around the center of earth, perpendicular to the axis.
-North of the equator receives more than 12 hours in the Summer, but less than 12 in the Winter
-South of the equator receives less than 12 hours in the Summer, but more 12 in the Winter
-On Spring and Fall Equinoxes everywhere on earth receives 12 hours of daylight, since neither the
Northern or Southern hemisphere is tilted toward or away from earth.
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Seasonal affect on the duration of insolation
In the winter the Direct Ray is at the Tropic of Capricorn (23.5 S) due to Earth’s tilt.
The maximum duration of insolation in NY is greatest around June. However the Maximum
temperatures occur in August.
The duration of insolation in NY is least around December. However, the ,minimum temperature occur
in February.
4) Properties of the Atmosphere and Lithosphere that effect Intensity of Insolation
A) Particulate Matter prevents Insolation from reaching earth’s Surface:
Aerosols like water droplets, ice crystals, dust and Pollutants can LOWER temperature because they
cause SCATTER (random reflections) that result in LESS insolation reaching Earth’s surface.
B) Clouds:
During the day clouds scatter insolation and prevent insolation from reaching earth’s surface. Thus it
is colder on a cloudy day.
However, at night the water vapor acts as a greenhouse gas and traps the reradiated infrared heat
energy. Thus it is warm and humid on a cloudy night.
C) Surface over witch air Exists
Air is first warmed by reradiated infrared radiation from the surface over which it exist. Convection
currents then distributes the warm, less dense air in the atmosphere.
What affects the temperature of the Earth’s surface? Color and Texture!
Remember! Light and smooth = reflect energy but Dark and rough absorb energy.
5) How does INSOLATION relate to the average Air Temperature in New York?
Although in NEW YORK, the intensity and duration of insolation is greatest in June, the Maximum
temperatures occur around August. Likewise, the intensity and duration of insolation is least around
December, but the minimum temperature occurs around February.
A similar phenomenon is seen daily. The intensity of the sun and the angle of insolation are greatest
around noon when the sun is highest in the sky. However, the Maximum temperatures occurs around
2PM , which is after the maximum insolation. The Minimum temperatures occur after the Sun rises.
What causes this temperature lag?
Even though the angle of insolation decreases, the Earth is still absorbing more energy than it’s
reradiating back into space so it continues to warm up. Likewise, When the Sun’s altitude first rises
the Earth is still reradiating heat into space, so the temperature continues to drops for a little while.
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
The Moon
 The __________ is Earth’s only natural
satellite
 It is estimated to be about
____________________ years old
Features
 The Moon’s interior is thought to have
_________, similar to earth
 The Moon’s surface is covered with
_________, caused by
________________ impacts.
The Moon’s Surface
 Dark areas called _________ (from Latin mare, meaning sea). These are ancient
lava flows.
 Light areas are ___________________, which are mountain ranges made of
lighter color rocks.
Moon Rocks
 Rocks on the Moon are made of ______________ similar to those on Earth.
Rotation and Revolution
 The Moon’s periods of rotation and
revolution are both _________ days.
The result is that the same side of the
Moon always faces Earth (the near side).
 However, it takes 29.5 days for the
Moon to completely revolve around the
Earth
 Moon has to revolve for 2 more days to
get back to the new moon phase
This occurs because the Earth is
revolving around the Sun.
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Phases Of The Moon :
 Moon Phases are apparent changes in shape due to the
position of the Moon in its orbit.
 Phase names:
– New
– Crescent
– Quarter
– Gibbous
– Full
 Waxing – becoming more visible
 Waning – becoming less visible
What causes the phase of the moon?
________________________________________
Why does the moon rise later and later each day?
_________________________________________
How many hours is the moon visible each day? _____
The phase of the moon are a ____________ event.





Moon’s Effect on Tides
________ are the periodic rise and fall of the ocean surface
Tides are caused by the _________________________ of the Moon and the Sun on
ocean water
High tide will occur when the __________ is overhead, as well as on the opposite side of
the Earth.
How many tides a day? ______
Why are there not exactly 12 hours between tides? ___________________________
Page #______
Unit 4: Astronomy
Earth Science- Ms. Gill
Note Packet #5
Phases and Tides
* The alignment of the Moon with
the Sun affect tides.
* At the full and new moon phase,
both are in line, causing a higher
high tide and a lower low tide.
This is called the
________________________.
* At the quarter phases, the Sun
and Moon work against each
other, resulting in weaker tides,
called
_______________________.
Eclipses
 ________________________ occurs
when the Sun’s light is blocked from
either the Earth or the Moon.
 We do NOT have solar and lunar
eclipse every month because the orbit
of the Earth and the Moon are along
different planes, the moon orbit is
tilted _________________.
Solar Eclipse
 _________________ – (Earth
goes into moon’s shadow) occurs
when the Moon blocks the Sun’s
rays from reaching Earth.
 It occurs only at new moon phase.
 Only a few people see it.
 Moon blocks light to the Earth.
Occur less often than lunar.
Lunar Eclipse
 ___________________ – (moon goes into
earth’s shadow) occurs when the Earth blocks
the Sun’s rays from reaching the Moon.
 Only occurs at full moon phase.
Earth blocks light to the moon.
Moon must be in Umbra for a Total Lunar
Eclipse.
Does not occur that often, moon orbit is tilted.
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