Pre and post-visit activities Navigating by the stars
Vocabulary List
Adult Education at Scienceworks
Pre-visit Activity 1: What is longitude and latitude?
Activity 2: Using the Southern Cross to find South
Activity 3: Measuring your latitude using hand-spans
Activity 4: Measuring your latitude using a quadrant
Post-visit Activity 5: Space spin-offs (Certificate I & II)
Activity 6: Where on Earth are you? (Certificate II)
These activities are designed to familiarise Certificate I and II students with the concepts and
vocabulary they will encounter when they visit Scienceworks to see the Guiding Lights planetarium
show, and to reinforce and extend their knowledge afterwards.
You may need to modify or extend some of the ideas presented to best suit the needs of your
students or student groups. Students should become familiar with the following words and their
meanings, particularly those used in the planetarium show synopsis and on-site activities, before
they visit Scienceworks.
Navigating by the stars
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Vocabulary list - Navigating by the stars
Adult Education at Scienceworks
Navigating by the stars
Words
Activities
Words
Activities
accurate, accuracy, accurately
adapted
celestial
charted
complementary (techniques)
connect, connection
demonstrates
(to) determine
device
earthbound
effect, effected
instruments
invent, invention
launch objects
navigate, navigating, navigation
orbit, orbiting
to orient (themselves)
predict
relatively recent times
satellites
solution
sophisticated
splendour
straightforward
unprecedented
utilized (utilised)
Show
Synopsis
coordinate (terrestrial coordinate
system)
devised
horizontal, horizontally
international convention
parallel
prime meridian
reference lines
sphere, spherical
terrestrial / celestial
vertical, vertically
Activity 1
altitude
arc
axis
constellation
hemisphere
intersection
right angle
Activity 2
angular distance
Activity 3
Activity 4
chronometer
cross-staff
GPS (Global Positioning System)
kamal
latitude
longitude
quadrant
sextant
Scientific
terminology
brass
heavenly body
locate
secure
tabulated value
accurate
chronometer
illustrating
influenced or affected
instruments
invent, invention
latitude
navigational system
revolution, revolutionised
spin-off
On-site & Postvisit
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Activity 1: What is longitude and latitude?
Background information
Due to the enthusiasm of our great explorers about 500 years ago, the demand for
accurate maps and charts increased. It was only about a century ago that an
international convention devised a terrestrial coordinate system using the lines of
longitude and latitude. There are two main (imaginary) reference lines that divide the
Earth vertically and horizontally and are marked 0 degrees. The equator is one of them
and divides the Earth into two equal halves. The equator marks 0 degrees latitude and
the lines of latitude run parallel to one another, measuring the distance, north or south
from the equator. The North Pole lies at a latitude of 90 degrees North and the South
Pole lies at a latitude of 90 degrees South.
Adult Education at Scienceworks
Recognised latitude lines:
Navigating by the stars
The Tropic of Cancer
The Tropic of Capricorn
The Arctic Circle
Antarctic Circle
23.5
23.5
66.5
66.5
degrees
degrees
degrees
degrees
N
S
N
S
The Tropic of Cancer and the Tropic of Capricorn mark the furthest points north and
south of the equator where the Sun's rays fall vertically. The Arctic Circle and the
Antarctic Circle mark the furthest points north or south of the equator where the Sun
appears above the horizon each day of the year. Inside the Antarctic and Arctic Circles,
the Sun does not appear above the horizon for the winter months and never drops
below the horizon during the summer months.
The other 0 degree (imaginary) reference line is the line that runs vertically through the
North Pole, the South Pole and Greenwich in England. This line is called the prime
meridian. The prime meridian was chosen to go through Greenwich because Greenwich
Observatory played a major part in determining longitude at sea. Imaginary lines that run
from the North Pole to the South Pole divide the Earth into sections. These imaginary
lines are called lines of longitude or meridians and are measured east or west of the
Prime Meridian.
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Adult Education at Scienceworks
Using this coordinate system, one can locate any place on Earth with accuracy.
Some examples:
The latitude and longitude for:
a)
Melbourne
b)
Los Angeles (USA)
c)
Kenya
d)
Paris
38
34
1
48
degrees S, 145 degrees E
degrees N, 118.5 degrees W
degree N, 38 degrees E
degrees N, 2.20 degrees E
What you need
• Spherical object eg. foam ball, blown up balloon
• Texta
• Earth globe
• String
• Sticky-tape
Navigating by the stars
What to do
Use an Earth globe to help you do the following activity.
1 Mark in the North and South Pole on your spherical object.
2 Mark and label the equator half way around your spherical object as best as you can
either using a texta or sticking a piece of string horizontally around the diameter.
3 Add lines of latitude 30 degrees S, 30 degrees N, 60 degrees S and 60 degrees N.
(The lines of latitude are measured from the equator. Use the diagram on page 9
as a reference. )
4 Mark in and label The Tropic of Cancer (23.5 degrees N) and the Tropic of
Capricorn (23.5 degrees S).
5 Mark in and label the Arctic Circle (66.5 degrees N) and the Antarctic Circle (66.5
degrees S).
6 Mark and label the prime meridian that passes vertically through the North and
South Pole. (The lines of longitude are measured from the prime meridian, which
passes through Greenwich, England.)
7 Mark in lines of longitude 45 degrees E, 90 degrees E and 135 degrees E,
45 degrees W, 90 degrees W, 135 degrees W.
8 Find out the longitude and latitude of three different places you would like to visit and
mark the (approximate) positions using the scale on your model.
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Activity 2: Using the Southern Cross to find South
Background information
One of the things that that makes finding stars and constellations difficult is that the stars
seem to move slowly across the sky during the night, rising in the East and setting in the
West, just like the Sun during the day. From Southern Australia, if you watched the stars
for a few hours they would move like this (if you are facing South):
Adult Education at Scienceworks
East
SCP
West
Horizen
Some stars travel in a large arc across the sky, then disappear below the horizon. Other
stars never 'set' below the horizon but trace a circle in the sky. At the centre of these
circles is a point called the South Celestial Pole. This part of the sky is directly above the
South Pole of the Earth. That is, if you stood at the South Pole, the South Celestial Pole
would be directly overhead. During summer at the South Pole the Sun circles the sky and
never sets meaning it is daytime continuously. During winter the Sun never rises and it is
constantly night.
Navigating by the stars
In the Northern Hemisphere, a star called Polaris or the Pole Star marks the North
Celestial Pole. There is no star near the South Celestial Pole, so instead southerners
must use the Southern Cross to find South.
Once you are familiar with finding the Southern Cross, it can be used to find the direction
of south, at any time of night, at any time of year because the Southern Cross never sets
in our night sky, when viewed from the Southern part of Australia.
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What to do
To find South:
1 Find the Southern Cross.
2 Draw an imaginary line through the long axis of the Southern Cross beginning with
the star that marks the top of the cross (note: during summer the Southern Cross is
low in the sky and therefore upside-down).
3 Extend the line four and a half times the length of the cross.
4 This will bring you to the point in the sky called the South Celestial Pole.
5 From this point, drop a line vertically down to the horizon. This gives you the
direction of true South. (Compasses find magnetic north/south, not True North/South,
so a compass will measure magnetic south to be 11 degrees west of True South
in Victoria.)
Adult Education at Scienceworks
SCP
S
Alternative method of finding South:
This method involves using the two bright Pointer stars - Alpha Centauri and BetaCentauri - that lie near the Southern Cross in the constellation of Centaurus.
•
Navigating by the stars
•
After step 2 above, draw a perpendicular bisector between the two Pointers, that is,
a line starting at the mid-point between the two Pointers and coming out at right
angles. This line should cross the line you drew in step 2.
The intersection of these two lines is close to the South Celestial Pole.
SCP
S
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Activity 3: Measuring your latitude using
hand-spans
Background information
Latitude is the angular distance of a location north or south of the equator. The latitude
for Melbourne is about 38 degrees. The latitude of a location can be determined using
the stars, by measuring a height of a Celestial Pole above the horizon. In the Southern
Hemisphere we use the South Celestial Pole. If you are unfamiliar with using the
Southern Cross to find the South Celestial Pole, refer to Activity 4 in this education kit.
Adult Education at Scienceworks
In the Northern Hemisphere, the North Celestial Pole is used to measure latitude. The
North Celestial Pole is marked by the star Polaris. The distance measured from the
horizon to Polaris in degrees is equal to the latitude of a location in the Northern
Hemisphere.
You can make approximate angular measurements using your fingers and hands at
arms length which then allows you to find the positions of particular stars and
constellations, and even measure your latitude.
Measuring large angles:
Outstretch one arm so that it is parallel with the horizon. This arm will act as your
baseline. Hold your other arm straight up beside your head. Both arms are now at right
angles. A 45 degree angle can be made by moving your upright arm to half the 90
degree angle. With practice you can even divide the 90 degree angle into thirds and
measure a 30 degree angle.
Measuring smaller angles:
One finger width at arms length covers about two degrees of sky and can be used to
measure small distances between stars.
Navigating by the stars
Half a hand-span (at arms length) is the distance across the knuckles of one hand.
It covers about 10 degrees across the sky.
A whole hand-span is an outstretched open hand. It measures 20 degrees across
the sky.
Australian latitudes
Melbourne
Sydney
Brisbane
Adelaide
Perth
Hobart
Darwin
Canberra
~
~
~
~
~
~
~
~
38
34
28
35
32
43
12
35
degrees
degrees
degrees
degrees
degrees
degrees
degrees
degrees
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Adult Education at Scienceworks
What you need
• Clear night
What to do
1 On a clear night, find the Southern Cross and use it to find the approximate position
of the South Celestial Pole. (Refer back to Activity 2)
2 Measure your latitude by measuring the distance between the horizon and the South
Celestial Pole using hand-spans and finger width measurements as accurately as
you can.
3 Discuss how accurate the measurements are. Compare measurements with other
students. Who had the closest value to the tabulated value? Find out why.
Navigating by the stars
Question
1 If you were standing at the a) South Pole what would your latitude be?
b) North Pole
c) equator
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Activity 4: Measuring your latitude
using a quadrant
Background information
A quadrant is a very simple instrument that was used to determine the altitude of a
heavenly body. It was made out of wood or brass and came into widespread use around
1450. It takes its name from its shape which is a quarter of a circle. A cord with a small
weight or plumb bob made of lead or brass hangs down from the right angle which
establishes a vertical line of reference. The quadrant is held at an angle so that the
altitude of a heavenly body could be found from a simple reading on the scale.
Adult Education at Scienceworks
The following activity shows you how to make and use a simple quadrant.
What you need
• A4 cardboard
• Glue
• Scissors
• Worksheet ‘Measuring your latitude using a Quadrant’
• String 25cm
• Sticky tape
• Weight or washer
• Straw cut in half
What to do
1 Stick the worksheet onto the piece of cardboard.
2 Cut around the dark outline.
3 Poke a hole through the point marked ‘X’.
4 Insert the string from the graduated side of the quadrant and stick the string behind
the quadrant using sticky-tape so that it is secure.
5 Tie the small weight onto the other end of the string.
6 Stick a straw with glue or sticky tape so that it lines up with the dotted line.
Navigating by the stars
How to use the quadrant to measure your latitude:
Note: It is advisable to practise using the quadrant to measure the altitude of various
objects (eg. top of a building or church) during the daytime before using it to measure
latitude.
7 Go outside on a clear night and find the Southern Cross. Use the Southern Cross to
locate the South Celestial Pole as accurately as possible. (Refer to Activity 2)
8 Start with holding the quadrant so that the weight hangs down along the zero line on
the scale and the straw lines up with the horizon at eye level.
9 Then look through the straw and locate the South Celestial Pole. Since the quadrant
is no longer horizontal, the string will move.
10 Hold the string in place against the quadrant.
11 Read the number of degrees between 0 degrees and 90 degrees. You now have an
approximate measurement of your latitude. Repeat steps 8-11 three or four times so
that an average value can be calculated. Compare the result to the tabulated value
for your area.
Optional
12 Use your quadrant and star map to check the altitude of given stars on a clear night.
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Worksheet
ed line
x
30
20
Measuring your latitude using a quadrant
g dott
w alon
stra
0
10
x
front
0
10
20
30
40
45
50
60
Navigating by the stars
70
80
Adult Education at Scienceworks
glue straw along dotted line
90
40
50
45
60
70
80
fron
t
90
glue
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Activity 5: Space spin-offs
Certificate I and II
Background information
A space spin-off is an invention originally developed for the space program but then was
adapted to useful things we use every day.
What you need
• Research facilities
Adult Education at Scienceworks
What to do
Research another two space spin-offs that you make use of in your life and answer the
following questions for each one:
Questions
1. What was the object originally invented for?
2. What is the use of this object in every day life?
3. How did this object go from being a space related object to an object people use
every day?
4. Get into groups of four and share your information with the group.
5. Make a list of space spin -offs researched by your group members.
6. Produce a poster illustrating all the spin-offs in your list and display in the classroom.
Navigating by the stars
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Activity 6: Where on Earth are you?
Certificate II
Background information
A space spin-off is an invention originally developed for the space program but then was
adapted to useful things we use every day.
An example of a space spin-off is a ball point pen. It was originally invented for people in
space so they could write up-side-down.
What you need
• Research facilities
Adult Education at Scienceworks
What to do
1. Research the GPS (Global Positioning System).
Find out how this system revolutionised navigation
2. How has this invention influenced or affected your life directly or indirectly?
3. Research the history of navigation and draw a simple time-line that outlines the major
developments in the history of navigation.
4. Research the reasons for and against spending so much money on space research
and exploration and then prepare a debate.
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