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Foundations of Astronomy
Science and Religion in Schools Project - Unit 4a
The Scientific Account of the Beginning
The Sun
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Ball of super-hot gas
Core temperature 16 million
degrees ºC
Roughly 4.5 billion years old
Will last another 4.5 billion
years
A very typical star
The Solar System
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In this image, the planets are in the correct order
The relative sizes of the planets is about right, but the
distances are not
The Sun is the arc on the far left!
Mercury
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0.4 times Earth’s diameter
No atmosphere worth mentioning
Surface temperature 1700C on
average
Mercury rotates two times for
every three orbits round the Sun
Takes 88 days to orbit the Sun
Distance from the Sun is about
0.4 times that of Earth
Venus
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Clouds are too thick to see the
surface
Venus is bright as these clouds
reflect a lot of the sun’s light
Surface of Venus is hot (4600C)
Atmospheric pressure is about 90
times that on Earth
Surface features only ‘seen’ by
radar
Guess where?
Meteorites
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Lumps of rock from space that
generally burn up in the atmosphere
Some large ones make it to the
surface and can cause damage
The Moon
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Orbits the Earth
No atmosphere
Some water, as ice
Craters due to being hit
by meteorites
Probably made when a
giant meteor hit the
Earth and blasted part
of the crust into space
Phases of the Moon
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Moon keeps the same face
to the Earth
Time it takes to turn on its
axis, same as the time
taken to orbit Earth
Phases dependent on how
much of the Moon visible
from Earth is lit by the Sun
Mars
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Atmosphere is carbon dioxide
Atmospheric pressure is
0.75% of Earth’s
Smaller than Earth, but about
the same size of land area
Being well explored by
unmanned probes
Martian Surface
Olympus Mons
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Olympus Mons is the large
volcano in the top left
The pale features are
clouds drifting over the
region
Jupiter
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Largest planet in the solar
system
Composed entirely of gas
Black dot is the shadow of
Europa
Large red dot is a hurricane
- bigger than Earth
11 times the diameter of
Earth and a thousand times
more massive
Saturn
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Beautiful gas giant
Nearly as big as Jupiter
Ring system can clearly be
seen from Earth with even a
small telescope
Saturn’s rings
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Complex structure of rings
Large gap is the Cassini
division
The F ring contains
shepherd moons
The Moons lap each other
every 25 days
Can cause the rings to be
‘braided’
Uranus
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True colour image from Voyager 2
makes Uranus seem bland
Infra-red image from the Hubble
Space telescope shows more
activity and the thin ring system
Hubble image shows cloud
structure
Also that Uranus rotates on it side so it ‘rolls’ around the Sun, unlike
the other plants
Neptune
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Final gas giant
Similar in size to Uranus
Great dark spot was thought to be
a storm system, but could be a
‘hole’ like the hole in Earth’s ozone
layer
High altitude ‘wispy’ clouds can
also be seen
Pluto
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Pluto’s orbit crosses that of Neptune
Also highly angled with respect to the other planets
Pluto’s moon Charon was discovered in 1978
New planet?
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Discovered on 14 November 2003
Far beyond Pluto
Orbit yet to be worked out
Status as a planet to be determined
(is it big enough?)
Provisionally called Sedna, the Inuit
goddess of the sea, who was
believed to live in the cold depths of
the Arctic Ocean
The Milky Way
Andromeda Galaxy
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Nearest galaxy to the Milky Way
Still about 2 million light years away
In about 3 billion years, Andromeda
will collide with our galaxy
Can be seen with the naked eye on
a dark night
Deep Field
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One of the most important
pictures ever taken
Hubble space telescope
Try to count the number of
galaxies!
This patch of sky could easily
be covered by the end of your
finger at arm’s length