School Science Lessons
Astronomy experiments
Updated: 2008-04-21
Please send comments to: J.Elfick@uq.edu.au
Table of Contents
7.1.0 Instruments for astronomy
7.4.0 Sundials
7.14.0 Stars and planets
7.28.0 Celestial phenomena
7.36.0 Effects of the Earth's motion
7.44.0 Models and demonstrations
7.51.0 Space science
7.1.0 Instruments for astronomy
7.1 Simple refracting telescope
7.2 Simple reflecting telescope
7.3 Simple theodolite or astrolabe,
sextant
7.4.0 Sundials
7.4 Demonstration sundials
7.5 Flowerpot sundial
7.6 Find north by the length of a shadow during
the day
7.7 Sunrise and sunset
7.8 Make a sundial
7.9 Measure the altitude of the Moon and
the Sun
7.10 Make a range finder
7.11 Make a model earth
7.12 Time zones and sidereal time, ships watches
7.12.1 Great circles
7.13 Find due north
7.68
Demonstration sundials (Southern hemisphere)
7.69 Sundial for your home
7.70 Universal globe sundial
7.70B Parallel rays of the sun
7.70.5 Building sundials
7.70.6 Make a pocket sundial
4.42 The sun and sundials (primary)
7.14.0 Stars and planets
3.3.3 Astronomical unit, AU
3.8.0 Ellipse
7.14 Find the main constellations
7.14.1 List of constellations
7.15 Magnitude
7.16 Albedo
7.17 Azimuth and altitude, the
horizontal system
of co-ordinates
7.18 Find constellations from north of
the
equator, Northern hemisphere
7.19 Find constellations from south of
the
equator, Southern hemisphere
7.20 The equatorial system of
co-ordinates, latitude
and longitude, declination and right ascension, zenith, star chart for
the tropics
7.21 Apparent daily rotation of the sky, axis of
rotation of the Earth
7.22 Ecliptic, apparent yearly path of the Sun
against the background of stars
7.23 Obliquity of the ecliptic
7.24 Is Pluto a planet?
7.25 Model of the solar system
7.26 The "Morning Star"
and the "Evening Star"
7.27 Movements of planets
7.76 Make a constellarium
7.76B Umbrella constellarium
7.77 Seasonal shift of the sky
7.78 Tell the time and the date by the stars
7.78A Star calendar
7.78B Star clock
6.20 The Southern Cross constellation
(primary)
7.28.0 Celestial
phenomena
7.28 The phases of the Moon and its
apparent
position in the sky
7.29 Observe the Moon
for four weeks
7.30 Observe the
positions of the Moon
7.31 Observe "the man in the Moon"
7.32 Observe the rising and setting moon
7.33 Observe a solar
eclipse
7.34 Observe a lunar eclipse
7.35 Rotation period of the Sun
6.19 The moon and tides (primary)
7.36.0 Effects of the Earth's motion
2.239.3
Foucault pendulum
7.36 Foucault pendulum
7.37 Miniature
Foucault
pendulum
7.38 Seasonal change of position of the Sun,
solstice
7.39 Photograph star trails
7.40 Astrology and the zodiac
7.41 Circumference of the Earth, the method of
Eratosthenes, 250 B.C.
7.42 Equinox, celestial co-ordinate
system, latitude
and longitude, right ascension, precession of the equinoxes
7.43 Find the north-south line from the
Sun
7.51.0 Space science
4.129
Magnifying power of a lens
7.12 Star of Bethlehem and birth of
Jesus
7.14 Navigation data used by a ship at sea
7.16 Diurnal aberration of a star
7.51 Discover action-reaction on roller
skates
7.52 Build action reaction engines
7.53 Discover thrust
7.54 Discover weightlessness, reference
systems
7.55 Angle, degree, arc minute,
arc second, radian
7.56 Light year
7.106 Satellite launcher
7.107 Kepler's laws of planetary motion
(Johann Kepler 1571-1630)
7.108 Newton's universal law of gravitation,
gravitational
constant, G
7.109 Gravitational potential energy
7.44.0 Models and demonstrations
7.44 Phases of the Moon and lunar
eclipses
7.45 Simulated solar eclipse
7.46 Why an eclipse does not occur at
every new
and full moon
7.47 The cause of the seasons
7.48 Differences in the length of
day and night
7.49 Effects of the angle of the Sun's
rays on the
Earth
7.50 Calendars
7.101
Make a spectroscope for materials analysis
15.3.0.2 Rotational and
translational kinetic energy of the earth
7.12 Star of Bethlehem and birth of Jesus
If Jesus was born Sunday, 1 March, 7 BC, this was the year of the
triple conjunction of the same two planets when in 27 May, 5 October
and 1 December, Jupiter moved close to Saturn in the constellation
Pisces. The conjunctions were first calculated by the astronomer
Johannes Kepler in 1603. The first conjunction may have started the
magi on their journey to Israel. The second conjunction may have guided
them. The third conjunction in December may have pointed to the birth
of Jesus. However, there was also a conjunction of Venus and
Jupiter in Leo in June 2 BC. In AD 314 Emperor Constantine the Great
changed the date of the birth of Jesus from 1 March to 25 December to
be the same date as a pagan sun festival. The star seen in the east to
guide the wise men is only mentioned in the Gospel according to St.
Matthew.
7.14 Navigation data used by a ship at sea
Position: 10.23 UTC (Co-ordinated Universal Time (UTC) replaced
Greenwich Mean Time (GMT) as the World standard for time in 1986. It is
based on atomic measurements rather than the earth's rotation.
Greenwich Mean Time (GMT) is still the standard time zone for the Prime
Meridian (Zero Longitude).
20o57.05' S
039o52.82' W
Course: 32o
Speed: 18.8 Kts (knots)
Relative wind: 55 Km \ h
Depth of sea: 47 metres (154 feet)
N | | NE | | E
Ships time: 07.29
Water temperature: 25oC
Air temperature: 29oC
Conditions: Cloudy sky
Air pressure hPa
Beaufort Wind Scale 3 (Beaufort number 0 --> 12) (See Interesting
websites "Beaufort scale")
Wind direction: 8 km / h from South
Barometer: 1015 mb, 761 mm Hg, 30.00 inch
Tendency: Slowly increasing
7.16 Diurnal aberration of a star
An observer at the equator can observe a movement of any star to the
east at a rate of 0.32 seconds of arc per day due to the rotation
of the Earth on its axis. However, that observed movement reduces to
zero as the observer approaches the poles. Diurnal aberration of
a star is the direct evidence that the earth is not fixed in space.
7.68
Demonstration sundials (drawn for the Southern hemisphere)
Place an upright metre stick in the ground so that it is not likely to
be shaded from the sun. Mark the position of the top of the metre stick
on the ground at hourly intervals.
See diagrams 7.68A, 7.68B
7.69 Sundial for your home
See diagram 7.69
Make the base with a flat rectangular piece of wood, metal or
polystyrene. The gnomon ABC consists of a thin triangular piece of
metal or plastic and such that angle ABC = latitude of the place at
which the dial is being set up and angle ACB = 90o.
Use a spirit level to test that the base is horizontal. The central
line must lie along the north south line, i.e. the meridian. Erect the
gnomon vertically so that the hypotenuse points towards the Pole Star
in the Northern hemisphere and the celestial south pole in the Southern
hemisphere. For approximate results, make the hour markings by noting
the position of the shadow of the gnomon at hourly intervals, using a
watch set to local mean time. You can obtain more accurate results if
the markings are made on 15 April, 15 June, 1 September or 24 December,
when there is no difference between watch time and dial time. Errors of
up to 16 minutes are possible if you make markings on other dates. For
accurate hour markings, find the angles the markings make with BC using
the following formulae: tan IOC = tan 15osin lat.; tan IIBC
= tan 30osin lat; tan IIIBC = tan 45osin lat.;
tan IVBC = tan 60o sin lat; tan VBC = tan 75osin
lat.; tan VIBC = tan 90o sin lat. Since the markings are
symmetrical about the central line XY you do not need to calculate
other angles. If the base of the dial is erected vertically then the
angle between the gnomon and the base must equal 90o minus
latitude of that
place.
7.70 Universal globe sundial
See diagram 7.70A
With a globe of the earth you can make a sundial that shows the season
of the year, the regions of dawn and dusk, and the hour of the day
wherever the sun is shining. The globe is rigidly oriented as an exact
model of the earth in space, with its polar axis parallel to the
earth's axis, and with your own town "on top of the world". First turn
the globe until its axis lies in your local meridian, in the true north
and south plane. Find this by observing the shadow of a vertical object
at local noon, or by observing the Pole Star on a clear night, or by
consulting a magnetic compass, if you know the local variation of the
compass, the magnetic deviation. Turn the globe on its axis until the
circle of longitude through your home lies in the meridian. Tilt the
axis around an east west horizontal line until your home town stands at
the very top of the world. Now your meridian circle connecting the
poles of your globe lies vertically in the north south plane. A line
drawn from the centre of the globe to your local zenith will pass
directly through your home spot on the map. Lock the globe in this
position and let the rotation of the earth do the rest. Be patient and
do not turn the globe at a rate greater than that of the turning of the
earth. However, it will take a year for the sun to tell you all it can
before it begins to repeat its story. When you look at the globe fixed
in this proper orientation you can see half of it lighted by the sun
and half of it in shadow. These are the actual halves of the earth in
light or darkness at that moment. An hour later, the circle separating
light from shadow has turned westward and its intersection with the
equator having moved 15o to the west. On the side of the
circle west of you, the sun is rising; on the side east of you, the sun
is setting. You can count the hours along the equator between your home
meridian and the sunset line and estimate how many hours of sunlight
remain that day. Look to the west of you and see how soon the sun will
rise there. As you watch the globe day after day, you will become aware
of the slow turning of the circle northward or southward, depending
upon the time of year.
7.70B Parallel rays of the sun
BE CAREFUL! DO NOT LOOK AT THE SUN
THROUGH THE TUBE AS DIRECT SUN RAYS CAN DESTROY THE RETINA OF YOUR EYE.
1. To show that the sun's rays are parallel as they fall on the earth,
on a bright morning, point a piece of pipe or a cardboard tube at the
sun so that it casts a small, ring shaped shadow. If at the same moment
a person 120o east of you, one third of the way round the
world, performs the same experiment, that person points the tube
westward at the afternoon sun. Yet that tube and yours approximately
parallel. If you point the tube at the sun in the afternoon, and
someone far to the west simultaneously does the same in the morning,
that tube will approximately parallel to your tube. So when our globes
are properly set up, people all over the world who are in sunlight will
see them illuminated in just the same way.
2. You can tell from the global sundial how many hours of sunlight
any latitude receives on any particular day. Count the number of 15o
longitudinal divisions that lie within the lighted circle at the
desired latitude. Thus, at 40o north latitude in summer the
circle may cover 225o of longitude along the 40th parallel,
representing 15 divisions or 15 hours of sunlight. However, in winter
the circle may cover only 135o, representing nine divisions
or nine hours. As soon as the lighted circle passes beyond either pole,
that pole has 24 hours of sunlight a day, and the opposite pole is in
darkness.
7.70.5 Building sundials
See diagram 7.70.5
The gnomon is the part of the sundial that produces the shadow. The top
edge of the gnomon must slant upward away from the base, or horizontal,
at an angle equal to the latitude of the observer and towards the South
for an observer in the Southern hemisphere. The gnomon must be aligned
along the N-S meridian. The hour lines are marked on the other part of
the sundial, called the time plane. The configuration of the gnomon and
the time plane identifies the type of sundial that has been
constructed. In the diagram, the shaded area represents a sundial. The
top edge of the gnomon is parallel to the earth's axis and the angle,
gamma, between the top edge of the gnomon and the horizontal is equal
to the latitude of the observation site. A horizontal sundial has
the hour lines are marked on a time plane horizontal to the earth's
surface. You can use the data in Table 3 to construct your horizontal
sundial. The table contains hour angles for some cities and towns in
Queensland, Australia, calculated by using spherical trigonometry. Note
how the hour angles vary with latitude.
Table 3: Hour angles for the horizontal sundial
| Time AM |
Time PM |
Brisbane |
Rock-
hampton |
Mackay |
Towns-
ville |
Cairns |
Too-
woomba |
Longreach |
Mt. Isa |
| 11 hours or |
13 hours |
07.0 |
06.1 |
05.5 |
5.0
|
07.5 |
07.1 |
06.1 |
05.4 |
| 10 hours or |
14 hours |
17.8 |
12.9 |
11.7 |
10.8 |
09.5 |
13.0 |
12.9 |
11.5 |
| 09 hours or |
15 hours |
27.6 |
21.7 |
19.8 |
18.2 |
16.2 |
27.9 |
21.7 |
19.4 |
| 08 hours or |
16 hours |
38.4 |
37.5 |
31.9 |
29.7 |
26.7 |
38.8 |
37.5 |
31.4 |
| 07 hours or |
17 hours |
59.7 |
56.0 |
53.3 |
50.8 |
47.3 |
60.0 |
56.0 |
52.7 |
On a square sheet of cardboard draw a line perpendicular to one edge to
represent the 12h 00 m hour line. Use a protractor to draw lines
spreading out from the 12h 00 m hour line at the angles in the table if
you are in one of the places in Table 3. If you live in Queensland
outside these places, find out the latitude of your place and estimate
the hour angles, e.g. the hour angle corresponding to 11 AM and 1 PM
for Maryborough would be somewhere between 7.0o (Brisbane)
and 6.1o (Rockhampton). Label the hour lines as in the
diagram. Use another piece of cardboard to cut out the gnomon with one
angle equal to the latitude of your location. Attach the gnomon to your
sundial base along the 12h 00 m hour line with the angle equal to your
latitude pointing North. The angle shown in Figure 3 is the latitude of
Brisbane. Align the gnomon along the N - S meridian.
7.70.6 Make a pocket sundial
Cut a wire coat hanger in half and set the angle to the latitude of
your location. Attach the coat hanger to a cardboard base marked with
the hour lines and align the gnomon north south. Use the sundial to
investigate the altitude of the sun and the passage of time during the
day. Maintain daily records of the progress of sunrise and sunset to
the North and South.
7.76 Make a constellarium
See diagram 7.76Bd: Northern hemisphere, Southern hemisphere
7.76.1 A constellarium is a simple device used in teaching the shapes
of various constellations. Use a cardboard or wooden box and remove one
end. Draw the shapes of various constellations on pieces of dark
coloured cardboard large enough to cover the end of the box. Punch
holes on the diagrams where the stars are located in the
constellations. Place an electric lamp inside the box. When the lamp is
turned on and various cards are placed over the end of the box, the
constellations may be seen clearly.
Another way is to obtain several tin cans into which an electric lamp
may be fitted. Holes are punched in the bottoms of the cans to
represent the stars in various constellations. When the lamp is placed
inside a can and switched on, the light shows through the openings and
the shape of the constellations may be observed. The cans may be
painted to prevent rusting and kept from year to year.
7.76B Umbrella constellarium
Since an umbrella has the shape of the inside of a sphere, it
can be made into a constellarium that will illustrate portions of the
heavens and how they move. You will need an old umbrella that is large
enough for this purpose.
The Northern hemisphere: Using chalk, mark the North Star, or Polaris,
next to the centre on the inside of the umbrella. Consult a star map,
and mark the star positions for various constellations with crosses.
When you have filled in all the polar constellations, you can paste
white stars made from gummed labels over the crosses, or you may paint
the stars in with white paint. Later you can draw dotted lines with
white paint or chalk to join the stars in a given constellation. If the
handle of the umbrella is rotated in a counter clockwise direction, you
will see how the various stars trace a circular path about the Pole
Star.
The Southern hemisphere: South of the equator, the umbrella should be
pointed towards the southern celestial pole and we will therefore have
to turn it clockwise. As in the Northern hemisphere, the stars will
rise in the east and set in the west. In the diagram above you can see
some of the more prominent stars and constellations marked on the
umbrella.
7.77 Seasonal shift of the sky
As the earth travels in its orbit around the sun the constellations
seem to move across the sky. The materials required for observing the
shift are a star chart and a plumb line. Make observations as described
in 7.75, except that you make only one set of observations and record
the time. At least one month later, repeat the same observations in the
same way, at as nearly the same time of night as possible. When you
compare the two observations made at the same time of night, what
change do you see in one month, or more? How much change would occur in
one year, if the same rate continues? What does this mean, when you
recall that we tell time by the sun? Will there be a time of year when
you cannot see Orion, for example at all? Answer the same questions for
the Big Dipper and North Star, if you are north of the equator. What
about the Southern Cross if you are south of the equator?
7.78 Tell the time and the date by the stars
Because the stars appear to rotate one full revolution in 24 hours,
they can be useful in telling time, at least during those hours of
darkness when the stars are visible to us. Because the stars also make
one full revolution in a year, they can be used to tell us the time of
the year. And so we have not only a star clock, but also a star
calendar.
7.78A Star calendar
See diagram 7.78BN: Northern hemisphere | See diagram 7.78BS: Southern hemisphere
The dates round the edge of the star chart for
the Northern hemisphere
show when the corresponding part of the heavens is due north at
midnight. For the Southern hemisphere the dates show the part which is
due south at midnight. Knowing this you can easily rotate the star map
so that it corresponds to what you see in the sky. If you are north of
the equator and you have to rotate the map 15o clockwise
from the midnight position, the time is 1 a.m.; if you have to rotate
it 30o counter clockwise, the time is 10 p.m. South of the
equator it is the other way round since you are facing south. If you
have to turn the map 15o clockwise from the midnight
position it means that the time is 11 p.m. The times determined this
way are sun times and they may differ from your local standard time.
7.78B Star clock
Separate sets of diagrams are given below for the
northern and Southern hemispheres, one clock for each month. The nine o'clock positions of
the star clock's hand are marked of f at the middle of some months. Can
you fill in the nine o'clock positions for May, August and November?
Try to fill in midnight positions for June, September and December. In
the Southern hemisphere, locate roughly the southern celestial pole.
7.91 Star
trails in colour
The stars are as colourful as land subjects, but this is not generally
known because dark adapted eyes have low sensitivity to colour. High
speed colour film and a camera with at least an f 3.5 lens will record
the red star Betelgeuse in the constellation Orion, the yellow star
Capella in the constellation Auriga, and the gold star Albireo in the
constellation Cygnus. The constellation Cassiopeia contains two blue,
one white, one golden, and one green star. A good camera that can make
time exposures, a rigid tripod, and fast film are all you need. The
simple star charts in this book will help you to identify the
constellations. Your local public library may have books on amateur
astronomy which contain similar charts. Dial indicators that show all
the constellations overhead when the dial is set for the month, day,
and hour, are also obtainable in some countries. The earth rotates 15o
per hour, or 10 every 4 minutes. To us on the earth, it is easier to
appreciate this movement by assuming that the stars move. Furthermore,
the stars appear to rotate around your celestial pole. Each star near
the pole traces a tight circle in its movement, and as the distance
from the pole increases, the radius of curvature increases until the
stars above the equator appear to travel in straight lines. A star is a
true point source of light and no movement of the camera can be
tolerated unless you want pigtails for star images. All trouble can be
avoided if you mount your camera on a rigid tripod, cover the lens with
a cardboard, use a long cable release to open the shutter on time or
bulb, wait 3 seconds or so for the camera to stop moving, and then
remove the cardboard from in front of the lens. At the end of the
exposure, again cover the lens with a cardboard before closing the
shutter. Commercial processing laboratories will probably not recognize
star images for what they are and, unless you instruct them otherwise,
will return your negatives unprinted.
7.92 Photograph constellations
See diagram 7.92B
1. Photographs of constellations add an aesthetic purpose to
photographing star trails. The results make beautiful prints and slides
in both black and white and colour, and they prove to be a very
effective teaching medium. There are many techniques for photographing
constellations, but a favourite is as follows: select a particular
constellation, set up the camera, and expose for 30 minutes with high
speed black and white film, 400 ASA and a lens opening of f 11; then
cover the lens for 2 minutes, open it to f 4, and throw it slightly out
of focus; finally, uncover the lens for 3 more minutes. A diffusion
screen over the lens for the final exposure works just as well as
throwing the lens slightly out of focus. The resulting picture shows a
constellation that appears to be plunging through space with a tail
following each star.
2. Underexposed and discarded 35 mm film slides can be perforated
with a pinpoint in the form of various constellations. The slides can
be projected on to a screen or used in a viewer, and students can try
to identify the constellations. The slides can also be dropped into a
slot made in a mailing tube and held up to the light.
7.93 Photograph satellites
Satellites are a joy to photograph. Use the same camera technique as
for star trails, see above. Kodak Tri-X Pan film is an excellent
choice. Use Kodak HC-110 developer, diluted 1: 15 at 24oC
for 4 minutes. The main problem is to know ahead of time where to aim
your camera. There are several sources for this information: many
newspapers publish daily the times, the degrees above the western or
eastern horizon, and the direction of travel for all visible
satellites. Also, local astronomical observatories and amateur
astronomical clubs may be able to furnish the required data for you.
Satellite photography is particularly rewarding when the satellite path
crosses a well known constellation, or if you are extremely lucky,
perhaps two satellites will cross within your photograph. It is this
unknown factor that continues to attract the amateur, as well as the
professional, astronomical photographer.
7.101 Make a spectroscope for materials
analysis
See also 2.222
By using a sensitive instrument called a spectroscope, scientists are
of ten able to analyse the composition of materials located a great
distance away. The spectroscope has been used to determine the
composition of the sun and other stars and of the atmosphere of many of
the planets. Spacemen in the future will use this kind of device to
analyse the chemical composition of their immediate surroundings. Light
entering a spectroscope is split up by a diffraction grating to form
coloured bands, which we call a spectrum. Since each chemical element
shows certain characteristic bright Shoe box spectroscope lines in its
spectrum the material can thus be easily identified. The materials
required are a shoe box, replica grating, see science supply
catalogues, some masking tape, and a double edged razor blade broken in
two. Cut a hole of about 2 cm diameter in the middle of one end of the
box. Use tape to fix a piece of replica grating over the hole from the
inside. Cut a 2.5 cm X 0.5 cm slit, which should be parallel to the
lines of the grating, in the middle of the other end. Cover the slit
from the outside with a finer slit made from two halves of a razor
blade, edges facing each other. The two halves are held together and
fixed to the box with tape. The width of the slit should be about the
same as the thickness of a razor blade and is finally adjusted for the
best results, see diagram. Look through the spectroscope at various
luminous gases such as neon and argon in lamps or signs. Notice the
bright lines in the spectrum, which indicate that each element has its
own pattern.
7.106 Satellite launcher
See diagram 7.106
Materials required are a bucket, a football, a coat hanger, or other
suitable wire, sinker or weight, a piece of string and a test-tube or a
cap of some sort.
Place the ball securely in the bucket. Bend the wire so that about 30
cm of it is straight and the rest is curved into a circular base as
shown in the sketch. Using masking tape, secure the circular portion on
the ball, allowing the straight, 30 cm portion to stand upright in the
centre of the top of the ball. Attach the sinker or weight to the
string. Fasten the other end of the string to the test-tube or cap with
tape. Invert the cap on top of the upright wire, see diagram. Explain
that the ball represents the earth, and the sinker represents the
satellite. All that it takes to set the sinker into motion in any
direction is the tap of a finger. Let the students find out what
happens when the satellite is launched in the following different ways:
1. With a slight tap, push the sinker up and away from the surface of
the ball, as shown in the figure. The sinker moves up and then falls
back to the starting point. This is how an object travels when it is
projected at low speed straight up from the earth.
2. With a slight tap, push the sinker of f the surface of the ball at
an angle. Show by a diagram what happens. The sinker moves away from
the ball and then falls back at some distance from the starting point.
The distance spanned depends upon the angle of launching and upon the
forcefulness of the tap.
3. With a stronger tap, push the sinker of f the surface of the ball
at an angle. Make a diagram of the orbit. The sinker moves away from
the ball, circles it, and lands. Evidently, a complete orbit passes
through the starting point of the orbit.
7.107 Kepler's laws of
planetary motion
(Johann Kepler 1571-1630)
Law 1. The orbit of a planets is an ellipse, with the sun at one focus
of the ellipse.
Law 2. Each planet moves such that a line connecting the planet to the
sun would sweep equal areas in equal times.
Law 3. The ratio of the square of the time of planetary revolution
(sidereal period) to the cube of its distance from the sun is
constant
for all planets.
7.108 Newton's
universal law of gravitation, gravitational
constant, G
Any two particles of matter attract each other with a force directly
proportional to the product of their masses and inversely proportional
to square of the distance between them,
F = m1m2G/d2
F = force of gravitational attraction
m = mass of a particle
d = distance between the particles
G = gravitational
constant
G = 6.67259 X 10-11 Nm2kg-2
7.109 Gravitational
potential energy
The energy an object possesses because of its position in a
gravitational field is called its gravitational potential energy. On
the Earth the gravitational acceleration is about 9.8 m/s2.
The potential energy of an object at a height h above the ground
= the work required to lift the object to that height. The force
required to lift the object = its weight, so gravitational potential
energy = the weight of an object X times the height it is lifted.
In space, the force approaches zero for large distances. so the
gravitational potential energy near a planet is negative because
gravity does positive work as a mass approaches. The small mass
approaching the large mass of a planet it bound to it unless it can get
acces to enough energy to escape. The general form of the gravitational
potential energy of mass m is:
PE = -GM1m2/ r
G = the gravitation constant
M = mass of the planet
m = mass of the approaching object
r = distance between the centers of the planet and the approaching
object
7.14.1 List of
constellations
Latin name, English name
Andromeda, Andromeda
Antlia, Air Pump
Apus, Bird of Paradise
Aquarius (in the Zodiac), Water Bearer
Aquila, Eagle
Ara, Altar
Aries (in the Zodiac), Ram
Auriga, Charioteer
Bootes, Herdsman
Caelum, Chisel
Camelopardalis, Giraffe
Cancer (in the Zodiac), Crab
Canes Venatici, Hunting Dogs
Canis Major, Great Dog
Canis Minor, Little Dog
Capricornus (in the Zodiac), Sea Goat
Carina, Keel
Cassiopeia, Cassiopeia
Centaurus, Centaur
Cepheus, Cepheus
Cetus, Whale
Chamaeleon, Chameleon
Circinus, Compasses
Columba Dove
Coma Berenices, Berenice's Hair
Corona Australis, Southern Crown
Corona Borealis, Northern Crown
Corvus, Crow
Crater Cup
Crux, Southern Cross
Cygnus Swan
Delphinus, Dolphin
Dorado, Swordfish
Draco, Dragon
Equuleus, Little Horse
Eridanus, River Eridanus
Fornax, Furnace
Gemini (in the Zodiac), Twins
Grus, Crane
Hercules, Hercules
Horologium, Clock
Hydra, Sea Serpent
Hydrus, Water Snake
Indus, Indian
Lacerta, Lizard
Leo (in the Zodiac), Lion
Leo Minor, Little Lion
Lepus, Hare
Libra (in the Zodiac), Scales
Lupus, Wolf
Lynx, Lynx
Lyra, Harp
Mensa, Table
Microscopium, Microscope
Monoceros, Unicorn
Musca, Fly
Norma, Level
Octans, 0ctant
Ophiuchus, Serpent Bearer
Orion, Orion
Pavo, Peacock
Pegasus, Winged Horse
Perseus, Perseus
Phoenix, Phoenix
Pictor, Easel
Pisces (in the Zodiac), Fishes
Piscis Austrinus, Southern Fish
Puppis, Ship's Stern
Pyxis, Mariner's Compass
Reticulum, Net
Sagitta, Arrow
Sagittarius (in the Zodiac), Archer
Scorpius (in the Zodiac), Scorpion
Sculptor, Sculptor
Scutum, Shield
Serpens, Serpent
Sextans, Sextant
Taurus (in the Zodiac), Bull
Telescopium, Telescope
Triangulum, Triangle
Triangulum Australe, Southern Triangle
Tucana, Toucan
Ursa Major, Great Bear, Charles's wain
Ursa Minor, Little Bear, Cynosura, Dog's tail (the pole star is alpha in the tail)
Vela, Sails
Virgo (in the Zodiac), Virgin
Volans, Flying Fish
Vulpecula, Fox
History of experiments in this document
Astronomy and space science experiments (this document) is
a revision, updating and expansion of the New UNESCO source book
for science teaching, UNESCO, Paris, Third impression 1979, ISBN
92-3-101058-1 by Dr John Elfick, School of Education, University of
Queensland, Australia assisted by Mr R. Smith, Central Queensland
University, Australia, working under UNESCO contract 8347201.
The first stage in the editing process was done in China and was
published in Chinese as "GUOWAI ZHONGXUE SHIYAN DILI (Overseas Middle
School Experiments - Geography) J. Elfick editor Author(s): Lin Peiying
and Zeng Hongying, Capital Normal University Press, Beijing, December
1996 ISBN 7-81039-805-9/G.662 Price Yuan 7.50. The difficult work of
co-ordination and interpretation was done by UNESCO Assistant Programme
Officers Mr Howard Jiang and Ms Ye Mai. The publication was used for
inservice training and was thoroughly reviewed by geography teachers in
China. This book was on the Ministry of Education, People's Republic of
China "All China Approved Book List for primary and Secondary Schools"
and is on sale to the public in China. This book was designed to give a
wider choice of experiments to teachers of geography in Chinese middle
schools. The amount of descriptive detail in the experiments is
designed to be the minimum needed for doing the experiment by a trained
geography teacher. Each experiment is thought to be one of the simplest
and least expensive ways of displaying the concept. However, a teacher
should check the experimental details in a geography text recommended
for
use in that school system.