Download The Official Magazine of the University of St Andrews Astronomical Society

The Official Magazine of the University of
St Andrews Astronomical Society
Contents
President’s Pen
2
UKSEDS Conference
2
Orion – Mythology
4
Orion – Science
5
Blue Dot
7
Space Quiz
10
The Universe
11
Star Article:
10 Things To Do to Make You Feel More Connected to Space 12
The Cosmic Ray Conundrum
13
For Sale
14
Lucky Charms Found in St Andrews
15
Editor’s Note
15
Planetary Motion
16
1
President’s Pen
It’s been an action-packed start to the year - beach games, cinema nights, talks,
conferences, observing…Astrosoc has been busy! My personal highlight so far has
been the UKSEDS conference (more on that later) although the cinema night proved
popular. Unfortunately there haven’t been many clear observing nights this semester
but we’re still hoping for a few before Christmas. Don’t worry though, the fun doesn’t
stop here – we’ve plenty more lined up to keep you entertained! If you’ve got ideas
for events or want to discuss anything at a committee meeting just send us an email,
it really is that easy!
Katie
UKSEDS Conference
El Prez, Katie Dunlop, gives us a summary of Astrosoc’s recent adventure into the
exciting world of space conferences.
This semester Astrosoc affiliated with UKSEDS (UK Students for the Exploration and
Development of Space), the UK branch of an international organisation with strong
ties to space industry and academia. One of the perks of this was the chance to
attend the SEDS annual conference, held at the Open University in November. The
conference featured talks from prominent figures in the UK space industry, a careers
fayre and the opportunity for some unashamed networking. This seemed like the
perfect chance to kick start my career and so I, along with five other “enthusiastic”
members, undertook the long and arduous journey to the little known paradise that
is…Milton Keynes.
In all honesty, after waking up at some unearthly hour and then spending eight hours
on a train, Milton Keynes is not an ideal destination in anyone’s books. Purpose-built
in the 1960s, the city centre seems to be made entirely from concrete and was
promptly nicknamed ‘Sim City’ by a none-too-impressed member of our group!
However, things began to improve once we arrived at our hotel. Not only was the
accommodation nicer than we had expected, but we were sharing the building with
2
the Bulgarian Under-21 football team! (It’s a hard life representing the society, but
someone has to do it…) However we hadn’t ventured so far from home just to spend
a night on the town with some dashing young Bulgarians, and so we got some much
needed sleep before the conference the next day.
On arrival at the conference we were presented with some “goody bags” (always a
good start when you’re a poor student) and directed towards some tea and chocolate
biscuits (they know us students too well!). It was interesting to meet other students
from across the country who shared the same interests and career goals, although a
great number of them were engineering students. The day soon got underway, with
lectures on a variety of topics ranging from the development of the UK space industry
to student research opportunities in Scandinavia! My personal favourite was the
presentation by ‘Surrey Satellite Technology’, a world leader in the design,
manufacture and operation of high performance small satellites. I hadn’t previously
considered a career in satellite engineering, but the diversity of the company’s
activities proved inspirational and during the lunch break I headed to their stall at the
Careers Fayre to find out more. Held in the same venue as the sumptuous (and free!)
buffet lunch, the fayre featured some big names such as EADS Astrium, LogicaCMG
and Surrey Satellite Technology Ltd. There were also representatives from the
Swedish Institute of Space Physics and the British Interplanetary Society, among
others. The six of us spent the lunch break dotting from stall to stall asking for
careers advice and stuffing enough free stationery to last a lifetime into our pockets!
After another few hours of lectures in the afternoon we headed back to the hotel to
get ready for the evening’s scheduled social event. UKSEDS had hired the top floor
of a club in the city centre and we St Andreans wasted no time in showing everyone
how a night out should be done! The club hosted one of the most impressive vodka
bars I’ve ever seen (birthday cake flavoured vodka shot anyone?) and over a few
“quiet” drinks we soon got to know the other conference attendees.
The morning came far too quickly and soon we were packing our suitcases and
starting the marathon journey back to St Andrews. The trip had been great fun, and
the conference allowed several of us to get a better idea of where we’re heading after
university.
3
I would like to take this chance to thank the Physics & Astronomy Student Staff
Council and the Students’ Union for the generous grants that allowed us to attend the
conference.
Orion – Mythology
In the first of a two-part article, Anna Louise Richards explains to us the ancient
stories that surround one of the most well known night sky constellations.
Orion is one of the most recognisable constellations
in the sky and unfortunately his story is also one of
the most convoluted, with many uncertainties and
variations occurring in regards to his birth and death. I
have tried to fit as many of the stories related to Orion
in as possible, whilst making the story understandable
and continuous.
Orion was the son of Poseidon, god of the sea, and
Euryale, a daughter of Minos. He was a handsome
giant gifted with the ability to walk on water and a
magnificent hunter. He served under King Oinopion on the island of Chios as a
huntsman until one day he caught sight on his beautiful daughter, Merope. Despite
clearing the island of all wild beasts and bringing the spoils of his endeavours to his
beloved as gifts, Oinopion refused the marriage. One day, having gotten drunk, he
4
forced his way in Merope's rooms and raped her. As a punishment for this Oinopion
enlisted the help of the god Dionysos to throw Orion into a deep sleep, during which
Oinopion blinded him. Desperate to restore his sight and return to life as a hunter
Orion travelled across the sea to Lemnos, the home of Hephaistos god of metalwork
and sculpture, and begged for his help. Lending Orion his assistant Kedalion,
Hephaistos told Orion to travel to the golden palace of Helios, the Titan god of the
sun and sight, whose powerful beams would restore his sight.
After returning to Chios and unsuccessfully trying to find King Oinopion in order to
extract revenge, Orion retired to the island of Delos where he became the
companion of Artemis, goddess of the hunt. However, her twin brother, Apollo,
became jealous of their relationship and one day he challenged Artemis to hit a
small dot that was in the middle of the sea. Never one to pass up a chance to show
of her skills Artemis shot at the dot, little knowing that it was actually the head of
Orion, who was swimming in the sea. In her grief she asked Zeus to place Orion as
a constellation in the sky, along with his hunting dogs and a hare to chase. Thus
Orion takes pride of place in the sky, an icon of strength for all to see.
References:
http://www.theoi.com/Gigante/GiganteOrion.html
http://www.ufrsd.net/staffwww/stefanl/myths/orion.htm
Orion – Science
In the second piece of this two-part article on Orion, Emily Ramsden explains to us a
bit of the science surrounding the Orion constellation.
Orion is positioned on the celestial equator, meaning that you can see him from
declinations 67 South all the way to 79 North, but only during the winter, and he is
the 26th largest constellation in the sky out of the official number of 88. The Hunter is
5
highest in the sky at 10pm from December to January, so there is no excuse not to
have a quick look when you’re out at night!
Betelgeuse (which can be
pronounced in a variety of ways, but
my personal favourite is ‘beetle
juice’) is the red star of his right
shoulder (the top left star). It’s a
variable red supergiant with
magnitudes between 0 and 1.3 in a
cycle of six years. It’s 430 light years
away.
Rigel is the bright blue star of Orion’s left thigh (the bottom right star). It’s a blue
supergiant with a magnitude of 0.2, is the brightest star in the constellation, and the
seventh brightest star in the sky. It’s 770 light years away.
Now of course everyone recognizes Orion’s belt first off, but if you look below the
middle belt star, to the bright stars in a vertical line below it, you will see Orion’s
sword. I point this out because in the area of the sword lies The Orion Nebula,
otherwise known as M42. The Orion Nebula is a stunning cloud of glowing gas,
where baby stars are forming, and is a fairly distant 1500 light years away. It is
visible to the naked eye, but you might want to use binoculars or a telescope to bring
out all the beautiful detail. If you want a good look, why not suggest it at the next
observing night?
References:
http://www.biochem.szote.u-szeged.hu/astrojan/orion.jpg
Stars and Planets – Ian Ridpath
6
Blue Dot
Jonathan Pattrick has brought to our attention a fantastic, but little known, image
which might help you change your perspective on the Earth and its place in the
Universe.
Studying astronomy and the astronomical distances concerned regularly reminds us
of how incomprehensibly large the universe actually is and often puts things into a
different perspective than we are normally used to. I feel this is best put across by
the astronomer Carl Sagan and his words regarding a photo of the Earth taken from
Voyager 1. I therefore would like to share the following with you and hope you find it
as capturing and thought-provoking as I did.
The photo itself was taken as Voyager was leaving the solar system and is from a
distance of more than 4 billion miles from Earth, showing our planet as a faint point
of light taking up 0.12 pixels of the original photo. It was named Pale Blue Dot.
7
Carl Sagan wrote, of this image:
“Because of the reflection of sunlight off the spacecraft, the Earth seems to be sitting
in a beam of light, as if there were some special significance to this small world. But
it's just an accident of geometry and optics. The Sun emits its radiation equitably in
all directions. Had the picture been taken a little earlier or a little later, there would
have been no sunbeam highlighting the Earth.
And why that cerulean color? The blue comes partly from the sea, partly from the
sky. While water in a glass is transparent, it absorbs slightly more red light than blue.
If you have tens of meters of the stuff or more, the red light is absorbed out and what
gets reflected back to space is mainly blue. In the same way, a short line of sight
through air seems perfectly transparent. Nevertheless - something Leonardo da
Vinci excelled at portraying - the more distant the object, the bluer it seems. Why?
Because the air scatters blue light around much better than it does red. So the bluish
cast of this dot comes from its thick but transparent atmosphere and its deep oceans
of liquid water. And the white? The Earth on an average day is about half covered
with white water clouds.
We can explain the wan blueness of this little world because we know it well.
Whether an alien scientist newly arrived at the outskirts of our solar system could
reliably deduce oceans and clouds and a thickish atmosphere is less certain.
Neptune, for instance, is blue, but chiefly for different reasons. From this distant
vantage point, the Earth might not seem of any particular interest.
But for us, it's different. Look again at that dot. That's here. That's home. That's us.
On it everyone you love, everyone you know, everyone you ever heard of, every
human being who ever was, lived out their lives. The aggregate of our joy and
suffering, thousands of confident religions, ideologies, and economic doctrines,
every hunter and forager, every hero and coward, every creator and destroyer of
civilization, every king and peasant, every young couple in love, every mother and
father, hopeful child, inventor and explorer, every teacher of morals, every corrupt
politician, every "superstar," every "supreme leader," every saint and sinner in the
history of our species lived there - on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood
spilled by all those generals and emperors, so that, in glory and triumph, they could
8
become the momentary masters of a fraction of a dot. Think of the endless cruelties
visited by the inhabitants of one corner of this pixel on the scarcely distinguishable
inhabitants of some other corner, how frequent their misunderstandings, how eager
they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some
privileged position in the Universe, are challenged by this point of pale light. Our
planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all
this vastness, there is no hint that help will come from elsewhere to save us from
ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at
least in the near future, to which our species could migrate. Visit yes. Settle, not yet.
Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character building experience.
There is perhaps no better demonstration of the folly of human conceits than this
distant image of our tiny world. To me, it underscores our responsibility to deal more
kindly with one another, and to preserve and cherish the pale blue dot, the only
home we've ever known.”
Carl Sagan (1934-1996)
Contact the Committee
President
Katie Dunlop (kld27)
Vice-President
Colin Simpson (ccs2)
Treasurer
Emily Ramsden (evr)
Secretary
Ciara Quinn (cq9)
Observing Directors
Ciara Quinn & David Mundy (dhm5)
Webmaster
Gerrard Brown (gmb24)
Magazine Editor
Colin Simpson
1st Year Rep
Frances Crimin (fc87)
Ordinary Members
Lydia Jagger (ljj4) & Darren Watters (dcw7)
9
Space Quiz
Question 1: What is the largest planet in the solar system?
a) Jupiter
b) Saturn
c) Earth
Question 2: What is the nearest star to the Sun?
a) Sirius
b) Vega
c) Proxima Centauri
Question 3: The 'War of the Worlds' is about an attack from which planet?
a) Saturn
b) Pluto
c) Mars
Question 4: The first moon landing occurred in July of what year?
a) 1959
b) 1969
c) 1979
Question 5: Who discovered the planet Uranus in 1781?
a) William Herschel
b) Carl Sagan
c) Edwin Hubble
Question 6: Who was the first man in space?
a) John Glenn
b) Timothy Leary
c) Yuri Gagarin
Question 7: What was the name of the first dog in space?
a) Lassie
b) Laika
c) Rasputin
Question 8: The Milky Way's centre is in the direction of which constellation?
a) Sagittarius
b) Ursa Major
c) Leo
Question 9: What is the atmosphere of Mars primarily composed of?
a) Carbon Dioxide
b) Oxygen
c) Nitrogen
Question 10: What is the name of Pluto's only known moon?
a) Betelgeuse
b) Charon
c) Christy
Answers can be found on trusty old Wikipedia. No joke…
10
The Universe
Frances Crimin shares her thoughts with us on the wonders of the vastness of the
Universe we live in.
Think of a sunny beach with fine, sparkly sand stretching on for miles ahead.
Imagine picking up a handful of the sand and counting the grains, one by one,
as they fall through your fingers.
Now count all the grains on the beach as far as you can see into the distance.
After that, try counting all the grains of sand on beaches you have visited,
and think of all the ones you have not.
There are more stars in the Milky Way than there are grains of sand on the
Earth.
And that is only one little galaxy in our infinite universe.
Incomprehensible, phenomenal, beautiful. That is The Universe we live in.
11
*Star Article*
10 Things To Do to Make You Feel More Connected to Space
Have you ever found yourself feeling disconnected from your intellectual pursuit of
the wonders of space, say when counting the number of boxes under a graph? If so
don’t worry, as Frances Crimin presents 10 things to do to get back that connection.
1. Stick glow in the dark stars on your ceiling (you don't have to worry about
them being taken down in halls since you can't see them during the day)
2. Eat Milky Ways. And other Galaxies.
3. Watch Star Trek, and have a giggle at the same time.
4. Ask someone a question you've always wanted to know about the
universe (preferably someone who may know and not just a random stranger
who will get a bit scared).
5. Sit outside all night, just staring at the moon. Wrap up warm.
6. Draw stars on your face. And your hands. And all over your tutorial
questions.
7. Think about what you would name a star/planet/galaxy if you ever
discover one. Then buy a goldfish and call it that instead, until you find one.
8. Draw a picture of the 'inside' of a Black Hole.
9. Google a map of the stars above your house, print it off, run outside and
try to identify them.
10.
Listen to 'Drops of Jupiter' and dance about with your eyes closed.
'Tell me did you finally get the chance to dance along the light of day And
head back toward the Milky Way'... It also works with 'Lucy in the Sky with
Diamonds'.
12
The Cosmic Ray Conundrum
John Ilee presents to us the mysteries, and possible explanations, of the most mindbendingly energetic particles known to man.
Something in the Universe is creating particles with
energies higher than anything ever thought possible.
These subatomic particles pack the same kinetic
energy as a cricket ball moving at 50mph into
something 10-15 times smaller. Just think about that for
a minute, 0.0000000000000001 times smaller.
By
comparison, the most powerful particle accelerator (in
Fermilab) produces particles with energies 300 million
times smaller than these ‘Ultra-High-Energy’ cosmic rays.
Now comes the conundrum – what could be producing these? How could we find
out? Well, if you were investigating the highest energy particles known to mankind, it
would seem sensible that you would need the biggest observatory known to
mankind…
This is where the Pierre Auger Observatory
comes in. It was named after the person who
first discovered the phenomenon of a cosmic
ray (He theorised that they were all gamma
rays, hence the name, cosmic ‘ray’).
Located
in Argentina, the Auger observatory covers an
area of approximately 3000km2 – twice the size
of the area of Greater London. It detects the faint fluorescence light given off by the
air showers, and also the particles in the air showers themselves. It comprises of
1600 water tank detectors and several optical detectors to record data on these
events.
In the past few weeks, the Collaboration released a paper outlining that they had
matched the arrival directions of the ultra-high-energy particles with locations of
13
known Active Galactic Nuclei, galaxies at edge of the known universe with
monstrous black holes at their centre. The mechanisms that cause the particles to
be accelerated to such high energies are not well understood, but huge gravitational
and magnetic fields are thought to play an important role in the process.
For Sale
A little scrapped for cash, the Physics and Astronomy Department have no choice
but to sell some of their beloved possessions. Gareth Pritchard has scouted out
some of the best deals for your convenience.
•
Large telescope, one previous careful lady owner. Very high mileage
but in working condition. Partial service history. Requires electrician to ensure
operation. Due to backward wiring, must only be used in Australia. Telescope
operator included with price. Available for pickup only due to size, dome not
included due to sentimental value. £200,000 o.n.o, call JGT research staff on
01334 999 999
•
Medium sized lecture theatre, recently refurbished. Does not meet
requirements for current owner. All mod-cons, with multi-sliding presentation
interface and spacious seating. No windows so a useful purchase for users in
the field of high security or submarines. £A bottle of Oasis o.n.o, call man at
front desk on 01334 123 456
•
Vending machine x2. Confectionary distribution installations. Multiple
sections for different varieties of confectionary. Free large packets of crisps
(out of date) included due to size restrictions. Shake to release. £free o.n.o
call the number on the machine due to the porters not being able to help.
•
Aurora magazine. Up-to-date journal on the goings on within the
University of St.Andrews Astrosoc. Serious and humorous articles. £free, if
you’re reading this you have bought it already….or are you thieving
this…..this is not a library put it down…….i’ll tell…….thank you
14
Lucky Charms Found in St Andrews
The contributor of this article, probably motivated by a
strong surge of review essay related insanity, would like
to be referred to as our ‘reporter on magical creatures –
Ulyesses Black’. Enjoy the following slice of comic relief.
A local group of astronomers have been blessed by the
magnificent discovery of an Irish Leprechaun’s gold. The
pot ‘o’ gold (as it is known) was discovered in one of the
domes within the town’s observatory. The site is an
active research of the legendary Astronomy department
of the University of St Andrews. A spokesman for the legion of extraordinary men &
woman (as the population of St Andrews proudly name them) said ‘This discovery
means that finally we can finally budget for the inclusion of astronomy parties’. The
spokesman, a man who likes to refer to his head as the sun, then went on to say
that, ‘this once in a blue moon event is a massive success for our research staff and
we hope that further discoveries of unicorns and other mythical creatures can be
made in the near future.’
Further to this, an Irish student of the department said that she welcomed the
invasion of the Leprechaun’s who she misses terribly from her homeland. Clara
Guinn was very proud that her countrymen could help improve the already teeming
social climate of the department.
Editor’s Note
I have taken over the position of magazine editor for Astrosoc this year and this is my first
major publication, which I hope builds on the success of the Fresher’s Edition copy of the
magazine.
It has been very nice to see so many articles contributed this year, as getting zero
contributions up to the day of the deadline seems to be a regular source of stress for the
editor. However, I feel that this year has been a good success with plenty being submitted.
15
Planetary Motion
The motions of the planets on the night sky is a somewhat complex process, but
Johannes Biniok takes some time to explain to us in this in-depth article how it all
works.
For a very long time only few knew about the movement of the stars. That
knowledge was secret and with it came great power. The future, people believed,
could be read in the sky. None imagined there could be an underlying principle.
In the following I will introduce and explain planetary motion as first described by
Kepler. How it came about will be addressed and why it still could be useful to know
about that examined. Special emphasis shall be put on the second of his three laws.
Physical astronomy goes back to the first scientific description of planetary motion by
Johannes Kepler (1571 - 1630). Before that Geocentricism was agreed on, but
science was renewed during Renaissance and scientific advances would soon
follow.
The publication of De Revolutionibus Orbium Coelestium, "On the Revolutions of the
Heavenly Spheres", by Nicolaus Copernicus in the 16th century had the necessary
impact for astronomy to evolve [Dreyer 1953].
The author favoured Heliocentrism over Geocentrism and so did astronomers
afterwards. Interestingly it was not because of new scientific discoveries that
Nicolaus Copernicus discarded Geocentrism, but because Heliocentrism appealed
to him in its simplicity [Berger 2001]. Furthermore, "There was no observational
evidence to unequivocally prove, or even indicate, that Earth moved around the Sun"
[Berger 2001].
16
Kepler was confident that Heliocentrism corresponded to reality [Dreyer 1953]. Other
theories he disproved in his Prodromus Dissertationum Cosmographicarum
continens Mysterium Cosmographicum, "Harbinger essay on the World, containing
the World Secret", published in 1596. He was not only confident that Heliocentrism is
correct, but was also convinced there was a reason for the distances, velocities and
relations he found by observation [Dreyer 1953]. Where there is a reason, he was
certain, there is an explanation. Being a religious man, he expected that to be God's
design. Nonetheless he assumed that there was a mathematical description for
planetary motion.
His intention was to find a law connecting celestial objects, but he did not [Dreyer
1953]. Even though he was already certain by 1596 that planetary orbits were
caused by a force emanating from the Sun. He mistakenly thought that the force
should be inversely proportional to the distance. In 1609 Kepler wrote: "The sphere
of influence of the attraction which is in the moon extends as far as the Earth, and
incites the waters up from the torrid zone" [Cunningham 2007]. What Kepler
described are the tides. What he indicated we know as the gravitational force.
Kepler did not find the law connecting the Solar System. Instead he found three
remarkable laws describing planetary motion, hence called "Kepler's Laws".
Law I - From orbs to orbits
Law I is a statement: Planetary orbits are ellipses with the Sun in one of the foci.
Orbits were, until then, regarded as
orbs" meaning "perfect circles" [Berger
2001]. For planetary orbits are not
circles, predictions were not accurate.
To enhance predictions with orbs
"epicycles ", circles on circles, were
implemented. Kepler, on the other
hand, was able to do without any of
the epicycles by turning orbs into orbits, by reducing perfect circles to ellipses
[Berger 2001].
17
Law II - constant area velocity
Law II is in close relation to Law I. While Law I characterises the kind of orbits,
Law II describes how planets actually move.
In equal time intervals equal areas are swept out by an imaginary line connecting
Sun and planet. That means the "area velocity" is constant.
To achieve a constant area velocity, it is necessary for planets to orbit faster nearer
to the Sun and slower farther away. Perihelion is the point where planets orbit with a
maximum velocity, nearest to the Sun. Aphelion is the point farthest away from the
Sun, where the orbiting velocity reaches a minimum. A change in velocity implies
that planets accelerate.
Law III - astronomers' tool
Law III describes the relation between the orbital period of an object and its distance
from the object it is orbiting. It is especially useful for estimating the mass of a planet
that is orbited by moons.
18
O is the orbital period, a is the semi-major axis, M and m are the two masses, G is
the gravitational constant.
The first accurate approximation on the mass of Mars has been calculated using
Law III when Asaph Hall (1829 - 1907) discovered Phobos and Deimos in 1877
[Bracher 2005].
The second very important application is to calculate values for planets based on
relations to other planets: The squares of the time for circulation are proportional to
the cubes of the semi-major axes.
Nowadays that is mainly practised by so-called "hobby astronomers".
The time for circulation can be observed
easily, assuming the necessary equipment.
The distance to the Sun can easily be
calculated using a known Sun-Planet
distance. That would be the distance SunEarth, for that can be calculated using
Triangulation.
Kepler was never much of a practical
astronomer, although he did some
important observation on his own [Nasa 2004]. He could be regarded as an early
theoretical astrophysicist.
For his research on planetary motion Kepler mostly used the extraordinary accurate
observation records Tycho Brahe (1546 - 1601) had left to him [Dreyer 1953]. Only
because of the huge collection of data Tycho Brahe had acquired by observation on
his own, Kepler was able to work on the mathematical descriptions for planetary
motion.
For Kepler's Laws do describe planetary motion accurately, the Geocentric model
collapsed and Heliocentrism took over [Berger 2001]. That left Astronomy - physics
19
in general - without any theory. At that time it was not possible to explain why a
moving Earth does not fall to the centre of the Universe.
Though empirically proved to be accurate, Kepler's model was without theoretical
foundation until Isaac Newton (1643 - 1727) published his theory of Gravitation
[Berger 2001].
Today we face a similar situation. The physics to describe the very smallest
components of the Universe is without any theory, though put together under the
ominous name Quantum Mechanics. We do not know about the "why", but we work
on the "how". Kepler did exactly the same by describing planetary motion. The
explanation came a long time afterwards, but it did come.
History can teach us the scientific results, but also reveal how these came about.
Natural sciences might be mathematically exact, but the historical context should
also be considered.
Science is in progress, very dynamic and not always as clear as the mathematical
result might suggest.
References:
Berger, D (2001) The Failure of Theory: Models of the Solar System National Forum
Bracher, K (2005) Planets and their Moons Mercury 34: page 7
Cunningham, C (2007) Galileo versus Kepler: Two Minds on Tides Mercury 36: page 9
Dreyer, J (1953) History of the Planetary Systems from Thales to Kepler pp 372 - 379
Nasa (2004) The History of Johannes Kepler http://www.jpl.nasa.gov/news/featuresprint.cfm?feature=665 Date Accessed: 28th Augst 2007Planetary Motion
Contributors
Thanks go to: Katie Dunlop, Anna Louise Richards, Emily Ramsden, Frances Crimin,
Jonathan Pattrick, John Ilee, Gareth Pritchard, Johannes Biniok
Images: The images not part of the articles were taken from the APOD website.
Editor: Colin Simpson
© The Copyright of all material in Aurora remains with the individual contributors. Any unattributed work is that of the Editor. The use,
transmission or storage of material from this magazine is prohibited without the prior written consent of its author(s).
20