The Solar System: our corner of the Universe
http://www.nasa.gov/images/content/136063main_bm4_high.jpg Slide 2
The Solar System For thousands of years ancient astronomers saw
points of light that appeared to move among the stars. They called
these planets, meaning wanderers, and named them after the Roman
gods. If you look up at a clear night sky, you too will be able to
see many of the planets that the ancient astronomers saw. You might
also see an assortment of space junk and satellites that also move
in the night sky. Slide 3 Theories of the solar system Pythagoras a
Greek scientist who lived in the sixth century BC suggested that
the Earth was the centre of the universe Aristotle (384322 BC),
Hipparchus (died after 127 BC) and Ptolemy (127145 AD) proposed
more detailed models in which Earth was placed at the centre of the
solar system This type of model is known as the geocentric
(geo-earth) or Ptolemy model Slide 4 Geocentric Model
http://en.wikipedia.org/wiki/Image:Ptolemaicsystem-small.png Slide
5 Geocentric Model Science Focus 1: Coursebook Slide 6 Theories of
the solar system Another ancient Greek, Aristarchus (310230 BC)
questioned the geocentric model and proposed a model where the
Earth and other planets revolved around the Sun This is known as a
heliocentric model (helio = Sun) The geocentric model continued to
be favoured until the end of the fifteenth century In the 1530s,
Polish astronomer Nicolas Copernicus (1473 1543) agreed with
Aristarchus Slide 7 Heliocentric Model
http://en.wikipedia.org/wiki/Image:Heliocentric.jpg Slide 8
Heliocentric Model Science Focus 1: Coursebook Slide 9 Theories of
the solar system Galileo (15641642) was a strong supporter of
Copernicuss ideas, in 1609 he used a telescope for the first time
to make detailed observations of the Moon and planets; his
observations exposed errors in the geocentric model Tycho Brahe
(15461601) didnt support the heliocentric theory and took numerous
detailed measurements of the positions of stars and planets in an
attempt to improve the geocentric model Using Brahes data, German
astronomer Johannes Kepler (15711630) finally showed the
heliocentric model was correct Slide 10 The solar system The term
solar system takes its name from the object at the centre of it
allthe Sun, also known as Sol The nine planets of the solar system,
in order starting from closest to the Sun, are: Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto* (*now
known as a dwarf planet) A mnemonic device to remember the order
could be: My Very Elegant Mother Just Served Us Nine Pizzas What is
your mnemonic device? Slide 11 The solar system The planets each
orbit the Sun, rotating on their axes as they do so The time taken
for a planet to spin once on its axis is called its day, and the
time taken to orbit the Sun once is called its year All the planets
have days and years of different lengths Slide 12 How the planets
move The four innermost planets are called terrestrial (meaning
Earth- like) and orbit the Sun in almost circular orbits The larger
outer planetsJupiter, Saturn, Uranus and Neptuneare known as the
gas giants (or Jovian planets), because their outer layers are
composed of gases such as hydrogen and helium, and they move in
elliptical or oval orbits All planets move in the same plane (a
large imaginary flat surface) except for Pluto, whose orbit is
tilted by about 17 compared to the other planets orbits Slide 13
http://solarsystem.jpl.nasa.gov/multimedia/gallery/vis_orb.jpg
Slide 14
http://solarsystem.jpl.nasa.gov/multimedia/gallery/outer_orb.jpg
Slide 15 Sun http://en.wikipedia.org/wiki/Image:Sun920607.jpg
MythologyThe Sun God. Greeks Called it Hellos Mass333 400 times the
mass of the Earth Diameter1 392 000 km (109 x Earths diameter)
Gravity28 times that on Earth Surface Temperature 6000C (average).
From 4500 to 2000000C up to 15000000C in the core. Period of
rotation (day)Equator 26 Earth days, poles 37 Earth days Tilt of
axis122 Slide 16 Mercury
http://en.wikipedia.org/wiki/Image:Reprocessed_Mariner_10_image_of_Mercury.jpg
MythologyGod of travel, commerce and thieves Mass0.056 times that
of Earth MoonsNone Diameter4878 km ( = 0.38 x Earths diameter)
SurfaceSimilar to Earths moon Gravity0.38 times that on Earth
Surface Temperature 170C to 430C Period of rotation (day)59 Earth
days Tilt of axis0 Distance from Sun0.39 AU (58 million kilometres)
Time to orbit Sun (year)88 Earth days Slide 17 Venus
http://en.wikipedia.org/wiki/Image:Venus-real.jpg MythologyGoddess
of love and beauty Mass0.815 times that of Earth MoonsNone
Diameter12 103 km ( = 0.95 x Earths diameter) Surface Extensive
cratering, volcanic activity. Gravity0.9 times that on Earth
Surface Temperature460C Period of rotation (day)243 Earth days Tilt
of axis30 Distance from Sun0.72 AU (108 million kilometres) Time to
orbit Sun (year)225 Earth days Slide 18 Earth
http://en.wikipedia.org/wiki/Image:The_Earth_seen_from_Apollo_17.jpg
MythologyGaiamother Earth Mass 1.0 times that of Earth (5 980 000
000 000 000 000 000 000 kg) MoonsOne (the Moon) Diameter12 756 km
SurfaceTwo-thirds water, one-third land Gravity1.0 times that on
Earth Surface Temperatureaverage 22C Period of rotation (day)1
Earth day Tilt of axis23.5 Distance from Sun1 AU (150 million
kilometres) Time for light to reach Earth8 minutes Time to orbit
Sun (year)365.25 Earth days Slide 19 Mars
http://en.wikipedia.org/wiki/Image:2005-1103mars-full.jpg
MythologyGod of war Mass0.107 times that of Earth Moons 2
(Phobosdiameter 23 km, Deimos diameter 10 km) Diameter 6794 km ( =
0.53 xEarths diameter) Surface Soft red soil containing iron oxide
(rust). Cratered regions, large volcanoes, a large canyon and
possible dried-up water channels. Gravity0.376 times that on Earth
Surface Temperature 120C to 25C Period of rotation (day)1.03 Earth
days Tilt of axis25.2 Distance from Sun1.52 AU (228 million
kilometres) Time to orbit Sun (year) 687 Earth days Time to reach
Mars9 months Slide 20 The terrestrial planets
http://solarsystem.nasa.gov/multimedia/gallery/terr_sizes.jpg Slide
21 Jupiter http://en.wikipedia.org/wiki/Image:Jupiter.jpg
MythologyRuler of the Gods Mass318 times that of Earth Moons At
least 28 moons and four rings, including the four largest moons:
Io, Ganymede, Europa and Callisto. These are known as the Galilean
moons. Diameter142 984 km ( = 11.21 x Earths diameter)
SurfaceLiquid hydrogen Gravity2.525 times that on Earth Surface
TemperatureCloud top 150C Period of rotation (day)9 hours 55
minutes Tilt of axis3.1 Distance from Sun5.2 AU (778 million
kilometres) Time to orbit Sun (year)11.8 Earth years Slide 22
Saturn
http://en.wikipedia.org/wiki/Image:Saturn_from_Cassini_Orbiter_%282007-01-
19%29.jpg MythologyGod of agriculture Mass95.184 times that of
Earth Moons At least 30 moons and rings in seven bands Diameter120
536 km (= 9.45 x Earths diameter) SurfaceLiquid hydrogen
Gravity1.064 times that on Earth Surface Temperature180C Period of
rotation (day)10 hours 39 minutes Tilt of axis26.7 Distance from
Sun9.6 AU (1400 million kilometres) Time to orbit Sun (year)29.5
Earth years Slide 23 Uranus
http://en.wikipedia.org/wiki/Image:Uranusandrings.jpg
MythologyFather of Saturn Mass14.54 times that of Earth MoonsAt
least 21 moons and 11 rings Diameter51 200 km (= 4.01 x Earths
diameter) SurfaceLikely to be frozen hydrogen and helium
Gravity0.903 times that on Earth Surface Temperature220C Period of
rotation (day)17 hours 14 minutes Tilt of axis98 Distance from
Sun19.2 AU (2875 million kilometres) Time to orbit Sun (year)84
Earth years Slide 24 Neptune
http://en.wikipedia.org/wiki/Image:Neptune.jpg MythologyGod of the
sea Mass 17.15 times that of Earth Moons8 moons and 5 rings
Diameter49 528 km ( = 3.88 x Earths diameter) SurfaceFrozen
hydrogen and helium Gravity1.135 times that on Earth Surface
Temperature220C Period of rotation (day)16 hours 7 minutes Tilt of
axis29.3 Distance from Sun30.1 AU (4500 million kilometres) Time to
orbit Sun (year)165 Earth years Slide 25 The gas giants
http://solarsystem.jpl.nasa.gov/multimedia/gallery/gas_sizes.jpg
Slide 26 Pluto (dwarf planet)
http://en.wikipedia.org/wiki/Image:Pluto.jpg MythologyGod of the
underworld Mass0.002 times that of Earth Moons1 (Charon)
Diameter2300 km ( = 0.18 x Earths diameter) SurfaceIcy crust of
methan Gravity0.061 times that on Earth Surface Temperature223C
Period of rotation (day) 6 Earth days Tilt of axis122 Distance from
Sun39.6 AU (5914 million kilometres) Time to orbit Sun (year)249
Earth years In July 2015 (10 years after launch) the New Horizons
spacecraft will capture the first up-close imagery of Pluto, its
moons and a region of the outer solar system called the Kuiper
Belt. Slide 27 Eris (dwarf planet) Eris (centre) and Dysnomia (left
of centre). Discovered January 5, 2005, from images taken on
October 21, 2003 MythologyGreek goddess of strife Mass Moons1
(Dysnomia) Diameter2600 km ( 400 km) Surface Gravity Surface
Temperature243 and 217 degrees Celsius Period of rotation (day)>
8 h? Tilt of axis Distance from Sun37.78 AU to 97.56 AU Time to
orbit Sun (year)556.7 Earth years
http://en.wikipedia.org/wiki/Image:Eris_and_dysnomia2.jpg Slide 28
http://www.solarviews.com/cap/misc/obliquity.htm Comparing tilt of
axis Slide 29 The planets to scale. The rings of the gas giants are
not shown. Slide 30
http://solarsystem.jpl.nasa.gov/multimedia/gallery/solarsys_scale.jpg
(Distance between objects not to scale) Slide 31 How small are we?
source: Celestia (application) (Distance between objects not to
scale) Earth Slide 32 How small are we? source: Celestia
(application) (Distance between objects not to scale) Slide 33
Relative distance of planets Sun = 1300mm diameter (blown up
garbage bag) Mercury = 4.5mm (coffee bean) 54m from Sun Venus =
11.3mm (small blueberry) 101m from Sun Earth = 11.9mm (small
blueberry) 139m from Sun Mars = 6mm (pea) 213m from Sun image
source: Google Earth Slide 34 Relative distance of planets Jupiter
= 133.5mm (large grapefruit) 727m from Sun Saturn = 112.5mm (large
orange) 1332m from Sun Uranus = 47.7mm (Kiwi) 2681m from the Sun
Neptune = 46.2mm (nectarine) 4200m from the Sun Pluto = 2mm (grain
of rice) 5522m from the Sun image source: Google Earth Slide 35
Earths movement in space The ancient civilisations defined the
days, seasons, months and years by following the movements of the
Sun and Moon. Babylonians, Mayans, indigenous Australians and many
other cultures all developed complex ways to predict seasonal
changes. This enabled people to plan when to plant crops or move to
a new location in search of seasonal foods. Survival depended on
this ancient scientific knowledge of the Earths movement in space.
Slide 36 Earths movement in space The earth spins on its axis,
causing alternating day and night When Earth is in the position
shown, days are shorter in the southern hemisphere and longer in
the northern hemisphere. Science Focus 1: Coursebook Slide 37
Earths movement in space: one year The time taken by a planet to
orbit (travel around) the Sun is called a year. Earth spins on its
axis while it orbits the Sun The Earth spins once on its axis in a
day, and takes a year to orbit the Sun. Science Focus 1: Coursebook
Slide 38 Earths movement in space: seasons As the Earth orbits the
Sun, the tilt causes different parts of the Earth to experience
different heating effects At the summer solstice, days are longest,
and at the winter solstice, days are shortest. Between these two
times, at the two equinoxes, day and night are of equal length.
Science Focus 1: Coursebook Slide 39 Aboriginal seasons
Bininj/Mungguy (local Aboriginal people) recognise six seasons in
the Kakadu region: Gunumeleng - Pre-Monsoon Storm Season Gudjewg -
Monsoon Season Banggerreng - Knock 'em down storm Season Yegge -
Cooler but still humid Season Wurrgeng - Cold Weather Season
Gurrung - Hot Dry Weather
http://www.environment.gov.au/parks/kakadu/artculture/seasons.html
Slide 40 We choose to go to the moon. We choose to go to the moon
in this decade and do the other things, not because they are easy,
but because they are hard, because that goal will serve to organize
and measure the best of our energies and skills, because that
challenge is one that we are willing to accept, one we are
unwilling to postpone, and one which we intend to win, and the
others, too. (John F. Kennedy -- September 12, 1962) The Moon
http://www.youtube.com/watch?v=e08r5IRTbjE Slide 41 The Moon
MythologyGod of the night Mass0.012 times that of Earth Diameter
3476 km ( = 0.27 x Earths diameter) Gravity0.16 times that on Earth
Surface Temperature230C to 123C Period of rotation (day) 27.3 days
Tilt of axis5 Distance from Earth384,403 kilometres Time to orbit
Earth29.5 days Time to reach Moon3 days Date first visitedJuly 20,
1969 Notice that the time for the Moon to orbit the Earth is nearly
the same as the time it takes to spin once on its axisthis results
in us only ever seeing the one side of the Moon from Earth. The
other side is often called the dark side of the Moon since it had
never been seen until the Apollo missions. Slide 42 What does the
Moon do? The Moon has a great impact on life on Earth It changes
appearance over the course of one Earth month It is responsible for
the tides It is involved in solar and lunar eclipses Slide 43
Phases of the Moon The Moon takes about a month to orbit the Earth,
and spins at a similar rate, and therefore we always see the same
face of the Moon. How much of the Moons face we see depends on
where it is in its orbit around the Earth. We call these different
views phases. Imagine yourself on the Earth, under point A looking
towards Moon A. Because the Sun is directly behind the Moon, you
see nothing of the Moon. Now imagine yourself on Earth under point
C, looking directly towards Moon C. From here you would see only
half the Moon. Science Focus 1: Coursebook Slide 44 The Moon and
the tides As early as the second century BC, the Chinese had
recognised a connection between tides and the Moons cycle. About
twice a day the sea level rises to a high tide and falls to a low
tidethe average time between two high tides is 12 hours 25 minutes.
It was not until Newton proposed a theory of gravity in 1687 that
tides were understood to be the result of the Moons gravitational
pull on the Earth. Slide 45 The Moon and the tides The
gravitational force between two objects is only noticeable when one
or both objects are very large, as is the case with the Moon and
the Earth. The Moon attracts the oceans towards it, enough to cause
a bulge in the oceans facing the Moon. If this were the only effect
there would only be one high tide and one low tide a day, not two.
The Earths rotation, however, causes a similar bulge on the other
side of the Earth. Science Focus 1: Coursebook Slide 46 Solar
eclipse The word eclipse comes from the Greek word for abandonment
the eclipse was seen as the Sun abandoning the Earth. There are
three types of solar eclipses. Slide 47 Solar eclipse A - total
solar eclipse is when the Sun is covered by the Moon. B - annular
solar eclipse occurs when the Moon is at its greatest distance from
the Earth. C - partial solar eclipse is when the Moon covers only
part of the Sun. All solar eclipses occur when the Moon comes
between the Earth and the Sun and the Moons shadow falls on the
Earth. http://en.wikipedia.org/wiki/Image:Eclipses_solares.en.png
Slide 48 Solar eclipse, as seen from the International Space
Station - March 29, 2006.
http://en.wikipedia.org/wiki/Image:Eclipse_fromISS_2006-03-29.jpg
Slide 49 Solar eclipse On August 1, 2008 a total eclipse will be
visible from a narrow corridor through northern Canada (Nunavut),
northern part of Greenland, Siberian part of Russia, western
Mongolia, and China. Slide 50 Lunar eclipse A lunar eclipse occurs
whenever the Moon passes through some portion of the Earth's
shadow. This can occur only when the Sun, Earth, and Moon are
aligned exactly, or very closely so, with the Earth in the middle.
Hence, the Moon is always full during a lunar eclipse. A lunar
eclipse occurs at least two times a year, whenever some portion of
the Earth's shadow falls upon the Moon. Slide 51 Lunar eclipse The
Moon does not completely disappear as it passes through the umbra
because of the refraction of sunlight by the Earth's atmosphere
into the shadow cone; if the Earth had no atmosphere, the Moon
would be completely dark during an eclipse. The red colouring
arises because sunlight reaching the Moon must pass through a long
and dense layer of the Earth's atmosphere, where it is scattered.
Science Focus 1: Coursebook Slide 52 On August 28, 2007 a total
lunar eclipse will be visible in its entirety for all of Eastern
Australia and New Zealand. The partial eclipse begins at 18:51, and
the total eclipse occurs from 19:52 until 21:22 (EST).
http://sunearth.gsfc.nasa.gov/eclipse/LEmono/TLE2007Aug28/TLE2007Aug28.html
Slide 53 The Solar System How long would it take you to travel to
Pluto? How long would it take you to travel to Pluto? How far from
Earth is the furthest manmade object? How far from Earth is the
furthest manmade object? What would happen if we no longer had the
Moon? What would happen if we no longer had the Moon? When is the
next total solar eclipse in Australia? When is the next total solar
eclipse in Australia? Slide 54 References NASA (2007). NASA. URL:
www.nasa.gov. (Accessed August 15 2007) NASA (2007). NASA. URL:
www.nasa.gov. (Accessed August 15 2007)www.nasa.gov Whalley, K.,
Phillips, G., Rickard, G., Monckton, S., & Robrson, P. (2005).
Science Focus One. Sydney: Pearson Education Australia. Whalley,
K., Phillips, G., Rickard, G., Monckton, S., & Robrson, P.
(2005). Science Focus One. Sydney: Pearson Education Australia.
Wikipedia. (2007). Solar System. Wikipedia.
URL:http://en.wikipedia.org/wiki/Solar_system. (Accessed August 15
2007) Wikipedia. (2007). Solar System. Wikipedia.
URL:http://en.wikipedia.org/wiki/Solar_system. (Accessed August 15
2007)http://en.wikipedia.org/wiki/Solar_system
