Download Earth`s Tilt and Its Effect on Light and Seasons

Debra Kosloski
Earth’s Tilt and Its Effect on Light and Seasons
Grade 6 Science
(Two 60 minute Class Periods)
Scientific Investigation, Reasoning, and Logic
6.1
The student will plan and conduct investigations in which
a) observations are made involving fine discrimination between similar objects and organisms;
e) hypotheses are stated in ways that identify the independent (manipulated) and dependent (responding) variables;
f) a method is devised to test the validity of predictions and inferences;
i) data are organized and communicated through graphical representation (graphs, charts, and diagrams);
j) models are designed to explain a sequence; and
k) an understanding of the nature of science is developed and reinforced.
Interrelationships in Earth/Space Systems
6.8
The student will investigate and understand the organization of the solar system and the relationships among the various bodies that
comprise it. Key concepts include:
d) revolution and rotation;
e) the unique properties of Earth as a planet;
g) the relationship of the Earth’s tilt and the seasons;
Instructional Objectives: Appropriate instructional objectives should be included here. The objectives should specify measurable student
outcomes.
The student should be able to use a physical (globe and lamp) or pictorial (diagram) model to:
1) Explain how the relationship between the tilt of Earth's axis and its yearly orbit around the sun produces the seasons.
2) Explain how the Earth’s tilt on its axis changes the length of daylight received by Earth’s northern and southern
hemispheres.
3) Explain how the tilt of the Earth’s axis and its yearly orbit around the sun changes the amount of direct sunlight received by
Earth’s northern and southern hemispheres.
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Debra Kosloski
.
Lesson
Segment &
Time Est.
Day 1:
(60 minute
class
period)
Introductio
n
(Predict,
Explain)
(10”)
Body
(Observe)
(Explain)
15”
Materials
Instructional Sequence
Assorted globes
of different size, Warm-Up: (10 minutes) Predict: Elicit Students’ Ideas:
age,
manufacture,
*An assortment of Earth globes are displayed on the teacher’s lab table as the
etc. (one for
students enter the classroom.
each student lab
table)
1) Students will use their lab notebooks to draw a picture of the object as
displayed as a globe.
A lamp or
2) Ask the students to write down what they think these globes represent. (A
flashlight for
model of the Earth).
each lab table.
3) Students are asked to list observations (similarities and differences) of the
globes. (color representations, location of equator and poles, size, shape,
Student lab
position of the Earth on each display, etc.).
notebooks
4) Ask students to write what is the purpose of a globe. (Students may say
that it represents our Earth, decorate a classroom, help us to get a better
understanding of our Earth, a model, etc.)
5) Predict what effect the tilt of the Earth, as displayed on each of the globes,
has on the amount of direct sunlight received by the northern and southern
hemispheres as the Earth makes its revolution around the sun and record
predictions in lab notebook.
A lamp or
flashlight for
each lab table.
Teacher/Student
Actions
Include brief description
of what teachers and
students will be doing
during each
activity/segment of the
lesson.
Teacher: Visits each
student to be sure the
student understands the
activity and prompt
students who may be
confused.
Students are applying
their observation skills to
draw a picture of Earth as
a globe and to answer the
questions about the
globe.
Lesson:
Explain: (10 minutes) Discuss students’ predictions: S. share
predictions/explanations in a class discussion. Make sure to value all ideas.
Discuss s. predictions and rationales and have s. discuss, given the range of
predictions, which might be most reasonable.
Discuss student responses to above warm-up. Students will conclude that although
the globes may be of various size and color scheme, they all represent our earth,
are spherical and have a “tilt” of approximately, 23°. The Earth globe is a model
of our Earth and the tilt is always pointed toward the north star as the Earth
revolves around the sun. Ask the students if their original drawings included the
Teacher records student
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Debra Kosloski
Lesson
Segment &
Time Est.
Materials
Student lab
notebooks
Hands On
10”
A lamp or
flashlight for
each lab table.
Student lab
notebooks
Instructional Sequence
Teacher/Student
Actions
tilt? Add the north star, Polaris, to the picture and label it. Although the Earth is
observation (similarities
spherical, did you notice that it can be divided into two halves? These are called
and differences) on the
“hemispheres”. “Hemi” means “half”, and “sphere” is a ball-like shape. The
whiteboard or document
Northern Hemisphere, where the United States is located, is above the equator.
camera.
Australia is in the Southern Hemisphere, below the equator. Can you name any
Students: Share the data
other land masses that lie in the Northern Hemisphere? In the Southern
that they observed and
Hemisphere? Let’s see what happens in each hemisphere as the Earth makes its
add to their lists in their
revolution around the sun. Do the areas of the Earth receive the same amount of
lab notebooks
direct sunlight throughout the year (one revolution around the sun) – being sure to Students add the
keep the north pole always pointed to the North Star, Polaris? Let’s see!
following words to their
dictionaries:
Hands On Lab:
 23°
Observe: (10 minutes) S. conduct the investigation, make observations, etc.
 Direct light
Distribute a globe and light source to each lab table. Keeping the globe tilted
 Earth
toward a point in the classroom that will symbolize the north star, Polaris, the
 Earth’s tilt
students will work in small groups to maneuver the globe around the light source.  Equator
The students will notice that light travels in a straight line from the source.
 Globe
Students will observe that the surface of the Earth is curved. Light will not wrap
 Hemisphere
around the Earth, but if it hits a curved surface, the light will be “spread” over a
 Model
larger area. They will notice which hemisphere is tilted toward and away from the
 Northern
sun during various points of the Earth’s revolution. Are there times when the
Hemisphere
Northern Hemisphere is tilted toward the sun? Which direction does the Southern
 North Star, Polaris
Hemisphere point at that time? Does the Southern Hemisphere ever tilt toward
 Southern
the sun? Where is the Northern Hemisphere tilt at that time. When does each
Hemisphere
hemisphere receive the most amount of direct sunlight? When does it receive the
least sunlight? Are there ever times when neither hemisphere tilts toward the
sun? Which hemisphere gets the most sunlight at those times? What seasons
Teacher monitors group
occur when neither hemisphere tilts toward the sun?
activities and assists Lab
Explain: (15 minutes) (Small groups) S. discuss observations and their
Groups in moving the
explanation for these observations in small groups then develop a written
globes in a
explanation
counterclockwise orbit
Students will discuss what they have observed with their small groups and
around the light source
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Debra Kosloski
Lesson
Segment &
Time Est.
Materials
Instructional Sequence
now record their observations; including a drawing of the Earth at 4 major
positions (Where the Northern Hemisphere receives the most direct sunlight,
the least sunlight and the two locations where neither hemisphere is tilted
toward the sun, so that they receive about the same amount of sunlight).
Closure
(Explain,
con’t)
20”
Illuminated
Model of
the Earth
and Sun
Illuminated
Model of the
Earth and Sun
Explain/Debrief (20 minutes): Whole-class discussion of small group
observations/explanations using a Illuminated Model of the Earth and Sun.
Provide the scientific explanation to students.
1. What position of the Earth provides the most direct sunlight to the Northern
Hemisphere? What season is occurring in the Northern Hemisphere at that
position? What is happening in the Southern Hemisphere at this time? What
season are they experiencing?
2. If you were to move the globe one fourth of its revolution around the sun,
going counter clockwise, which hemisphere receives the most direct sunlight?
What season is the Northern Hemisphere experiencing? The Southern
Hemisphere?
3. Now move your globe so that it is now halfway around the orbit and note
which hemisphere, if any, is tilted toward the sun now? Where is the other
hemisphere tilted? Which season is occurring in each hemisphere?
4. Move the globe so that it is ¾ of the way around the “sun”. Which hemisphere
is receiving the most direct sunlight?
5. When did the two hemispheres receive the same amount of direct sunlight?
This was when neither hemisphere was tilted toward the sun. During the spring
in the Northern Hemisphere (fall in the SH) and again when the Northern
Hemisphere was having its fall (spring in the SH). There are two days during
the year when each hemisphere gets an equal amount of day and night. We
call that an Equinox. The Northern Hemisphere has its Spring (or Vernal)
Equinox on March 22, and its Fall or (Autumnal) Equinox in the fall on
September 22. What do you think is happening in the Southern Hemisphere
when the NH experiences its equinoxes?
6. During the summer, the days get longer until June 21st, the longest day and
shortest night in the Northern Hemisphere. During the winter the days
Teacher/Student
Actions
(the “sun”).
Students work in lab
groups to simulate the
Earth’s revolution around
the sun using a globe and
a lamp. They collect data
on their observations of
where the most “direct
light” strikes the globe as
it orbits. Students will
include a drawing of the
Earth and “sun” where
the Northern Hemisphere
would be experiencing
Winter, Spring, Summer
and Fall.
Teacher demonstrates
the revolution of the
Earth as it orbits the sun
using a Trappensee
Brand Illuminated Model
of the Earth and Sun.
Students use their
observations/notes to
answer the questions to
the right and summarize
their understandings.
Students include the
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Debra Kosloski
Lesson
Segment &
Time Est.
Materials
Instructional Sequence
continue to get shorter until December 21st, when the NH has its shortest day
and longest night.
7. Label your drawings with the seasons and the equinoxes for NH and SH.
Assessment
5”
Paper & Pencil
Teacher/Student
Actions
following words in their
lists w/ definitions:
 Autumnal (Fall)
Equinox
 Equinox
 Vernal (Spring)
Equinox
Cool Down: (5 minutes)
Exit Ticket-
1. Why does the Earth experience seasons?
2. Draw a sketch of the Sun and the Earth when the Northern Hemisphere is
experiencing its summer. What is the Southern Hemisphere experience
when Earth is in this position?
3. Which area of the Earth experience less variation of climate during its
seasons?
4. Why does this area have less variation in its seasons?
Students write/draw
their responses on a half
sheet of paper.
Teacher collects
assessment as students
exit the classroom.
Total Time
=60”
Day 2:
(60 minute
class
period)
*Flashlight (one
for each lab
5
Debra Kosloski
Lesson
Segment &
Time Est.
Introductio
n
(Predict,
Explain)
(5”)
Body
(Observe)
(Explain)
15”
Hands On
20”
Materials
pair)
*Student
Science
notebooks
Instructional Sequence
Warm-Up: (5 minutes)
1) What do you predict will happen if you take the beam of a flashlight and point
it straight down on a sheet of white paper?
2) What do you predict will happen if you take the beam of a flashlight and shine
it at an angle onto your white paper.
3) Using a flashlight, act out the two scenarios with your partner. Trace the shape
of the beam of light and label it as straight on or at an angle.
4) Is the shape of the beam of light that you drew on the paper the same or
different? Why?
Laptop or IPad
Cart
Lesson: (15 minutes)
Technology:
Ecliptic
Students will work in Pairs to explore the Computer Ecliptic Simulation to see
Simulator
how the angle of the sun’s rays changes throughout the year. They will notice
http://astro.unl.e that as the angle of the sun’s rays changes from the “normal” of straight on, the
du/naap/motion
ray’s light is spread over a wider area. The same amount of light is received, but
1/animations/se
due to the angle less light and heat energy from the sun is received. Students can
asons_ecliptic.h observe as the website travels through all twelve months and/or manipulate the
tml
program to visit individual months.
AIMS: Pasta
Parallels
http://www.gcis
dk12.org/cms/lib/
TX01000829/C
entricity/Domai
n/75/MS%208
%20Grade%20%20OL%20and
%20PAP/8.4%2
Hands On Activity (30 minutes)
1) Students will create a Key for their graph that associates the number of pasta
strands for the width of the sun beam reaching the earth.
2) Students will place the pasta strands side by side onto each sunbeam to
determine the width of the beam.
3) Students will color the beam on their graph to represent the Graph’s Key.
Complete the graph
4) Students will cut out the circle that represents our Earth and using the brass
fastener, attach it to the graph
Teacher/Student
Actions
Teacher visits each pair
of students to be sure that
they understand the
positioning of the
flashlight beam onto the
paper.
Students manipulate a
flashlight to simulate the
shape to the beam as it is
aimed perpendicular to
the paper and at an angle
(direct and indirect light).
Teacher models the
completion of the key as
the students complete
their own key.
Students will apply
teacher model to the
completion of their own
Key.
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Debra Kosloski
Lesson
Segment &
Time Est.
Materials
Instructional Sequence
Teacher/Student
Actions
0Weather/Pasta
%20Parallels.pd
f
Materials:
1)Pasta Parallel
packet for each
student
2)Several
Strands of Thin
Pasta at each
lab table.
3)Colored
Pencils or
crayons
4)scissors
5)Brass fastener
Closure
(Explain,
con’t)
15 “
Explain (continued):
Students will manipulate the Graph that they created to simulate which
hemisphere of the Earth receives more direct or indirect sunlight during the
year.
1. What do you notice about your ray graph?
2. On June 21, where are the most direct rays of the sun? Where are the most
indirect rays? What seasons are the Northern and Southern Hemispheres having
then?
3. On December 21, where are the most direct rays of the sun? Where are the most
indirect rays? What season are the Northern and Southern Hemispheres having
then?
4. How is the slant of the rays related to the seasons?
5. What kind of clothes do you wear in June? If you were to travel to Australia in
June, what kind of clothes would you take?
Students will manipulate
their Pasta Parallel graph
in order to answer the
questions.
Teacher will visit each
lab pair to insure that
they understand what is
being asked and that they
are manipulating the
graph correctly.
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Debra Kosloski
Lesson
Segment &
Time Est.
Assessment
5”
Total time:
60”
Materials
Instructional Sequence
6. Find the central, most direct rays. What is its farthest point north? What is its
farthest point south? What might the climate be like in this area? Why?
7. What happens to day (or night) in the Arctic (or Antarctic) Circle as it goes
through the different seasons?
8. If the Earth were not tilted, how would that affect us during the year?
9. What are you wondering now?
Cool Down – Exit Ticket
1) Explain how the relationship between the tilt of Earth's axis and its yearly orbit
around the sun produces the seasons.
2) Explain how the Earth’s tilt on its axis changes the length of daylight received
by Earth’s northern and southern hemispheres.
3) Explain how the tilt of the Earth’s axis and its yearly orbit around the sun
changes the amount of direct sunlight received by Earth’s northern and southern
hemispheres.
Teacher/Student
Actions
Students will be able to
answer the questions
independently.
Teacher will collect
student responses as they
exit the classroom.
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