THE JUNIOR ENCYCLOPEDIA OF SPACE
DWARF STARS
A Dwarf Star,
is a star, of average or low luminosity, mass, size, and size. Important
subclasses of Dwarf stars are White dwarfs and Red Dwarf's. The class of Dwarf
includes most so-called main-sequence stars, among which is
the Sun. The colour of Dwarf stars,
can be anything from blue to red, the corresponding temperature, varying from
high (above 10,000 K to low) to low (a few thousand degrees).
A COMETS COMPOSITION
What is a comet made of? We
once had this graphically demonstrated to us in an astronomy lecture! The
lecturer went to the trouble of: "Creating”, a comet (a la: "Here's
One I Made Earlier!"). He demonstrated this process for two hours! Gosh,
how exciting it was! Seriously though, the one other useful thing this lecture
taught us, was for acting purposes, and if you have the opportunity of acting
in horror films, and a vampire offers you a drink, which is a bit steamy
(actually containing dry ice used in this particular lecture), your lips must
never touch the glass, because the temperature will take the skin off your
lips, and you must mask drinking, from the glass!
But if you really want to
know what a comet is made of, then here goes: A comet is generally considered
to consist of a small sharp nucleus, embedded in a nebulous disc called the coma.
American astronomer Fred L Whipple proposed in 1949, that the nucleus,
containing practically all the mass of the comet is a "dirty
snowball" conglomerate of ices and dust.
Major proofs of the
snowball theory rest on various data. For one, of the obseved
gases and meteoric particles that are ejected to provide the coma and tails of
comets, most of the gases are fragmentary molecules, or radicals, of the most
common elements in space: hydrogen, carbon, nitrogen and oxygen. The radicals
for example, of CH, NH, and OH may be broken away from the stable molecules Ch4
(methane), NH3 (ammonia) and H20 (water) which may exist as ices or more
complex, very cold compounds in the nucleus. Another fact in support of the
snowball theory is, that the best-observed comets move in orbits,
that deviate significantly rom Newtonian
gravitational motion. This provides clear evidence, that the escaping gases
produce a jet action, propelling the nucleus of a comet slightly away, from it's otherwise predictable path.
In addition, short-period comets, observed over many revolutions, tend to fade
very slowly with time, as would be expected of the kind of structure, proposed
by Whipple. finally, the existence of comet groups,
shows thatcometary nuclei are fairly solid units.
The head of a comet,
including the hazy coma, may exceed the planet Jupiter in size. the solid protion of most comets,
however, is equivalent to only a few cubic kilometers. the
dust-blackened nucleus of Halley's comet, for example, is about 15 by 4km
(about 9 by 2.5mi) in size.
BIRR CASTLE
Birr Castle is very
significant to us in astronomical terms, because we visited the Castle in the
summer of 1993, when we went on holiday to the Irish Republic, and in the
Castle grounds, you have the chance to see the shell of a giant telescope,
which was something of a novelty in it's day, and it
was also very ahead of its time.
I will do a brief history
of the telescope first, and then I will put into my own words, about our
experiences there.
Lord Rosse
was obsessed with the idea of constructing a truly large telescope. He worked
for five years to find an alloy suitable for the mirror. His final choice was
composed of four atoms of copper to each atom of tin. This alloy was quite
brittle, however, and his first 36-inch-diameter mirror was composed of 16 thin
plates soldered to a brass famework. The moderate
success of this telescope encouraged Lord Rosse to
try to cast a solid 36inch mirror. After much experimentation he succeeded in
casting and cooling the mirror without cracking it, a serious problem in the
construction of all large telescopic mirrors. In 1842 he began work on a mirror
of 72inch diameter. Three years later, the four-ton disk was mounted and the
installation was completed. Fifty four foot in length, Lord Rosse's
telescope was used primarily to observe nebulae on these rare occasions when
weather conditions around his estate permitted. With his telescope, however he
discovered the remarkable spiral shape of many objects then classed as nebulae,
which are now recognized as individual galaxies. He studied and name the Crab Nebula. He also made extensive, detailed
observations of the Great Nebula in Orion. Though his telescope was dismantled
in 1908, it was not until the 100-inch reflector at the Mount Wilson
Observatory in California, that a larger telescope was used.
Lord William Parsons Rosse, the 3rd Earl of (1807-41)also
called Lord Oxmantown. He was born on 17th June 1800,
York England and he died on the 31st October 1867 at Monkstown,
County Cork, Republic Of Ireland. He was Irish in
origin, an astronomer, and builder of the largest reflecting telescope, the
Leviathan of the nineteenth century. In 1821, Rosse
was elected to the House of Commons as Lord Oxmantown.
he resigned his seat in 1834, but in 1841, inherited
his Father's earldom, and served as one of the Irish peers in the House of
Lords.
Birr Castle is situated in
the small town of Birr itself, which is a very pretty town in its' own right,
aside from the Castle, and it has a somewhat Georgian feel about it (like Bath,
England).
At Birr Castle, you can
only explore the grounds, as the Castle itself isn't open to the public, but
there are the grounds to explore, and there is the telescope itself of course,
and even though it is only a shell, it is well worth taking a look at it,
because one can easily imagine, what it must have looked like in its day. There
are display boards, telling you about the history, the construction of the
telescope, and the original eyepieces are on display, as well, but the mirrors
for the telescope, were ground down, because they were very costly to maintain.
There is also a sound commentary of the history and construction of the
telescope, courtesy of Patrick Moore, which you can listen to via a headset.
We have heard, since 1995,
that as the great telescope is such a popular tourist attraction, that a
consortium or possibly a University, are going to make it fully operational,
once more, and the last I heard, was that they were in the process of grinding
a new mirror, for the Leviathan. I haven't heard any more since, but I think it
may be something to do with the millenium. If I hear
anything more about it, I will add an update, on to this section.
We walked around the moat,
and the grounds were quite pretty. There were carriage rides, which were more
or less aimed at the children. There was one part of the Castle that was open,
but it was just a big tower in the Courtyard, which was aimed at Exhibitions.
We went to a free exhibition, which was about the early use of colour, in photography, which was quite interesting, and
finally, there was the Planetarium! I don't know whether that was a permanent exhibiton, but it wasn't like going to the London
Planetarium! It was very commendable in it's
own right, but it is an exhibition, that you have to pay for. The exhibition
consisted of a few display boards, and an audio visual display, set in a wall
monitor, which was very rare footage, of one of the former Soviet Unions Space exploration projects. this
consisted of a day in the life of the first Woman astronaut, Valentina (Vladimirovna) Tereskova. We saw her in a pretty orange dress, at the
hairdressers, having her hair styled, all beautifully done for propaganda
purposes!
To get into the
Planetarium, we had to crawl inside it! It was one of these, that have to be
blown up, by a wind machine, but the lecture of the constellations, which we
could see quite well, on the top of the planetarium, was informative, all the
same.
So, if anyone out there on
the Web, who may be interested in going to Birr Castle, in the Republic of
Ireland, we would fully recommend it!
THE MOON
Now, why are so few people
interested in our nearest neighbour in space? Over
the next few weeks we hope to add some shots (done via an ordinary camera) of
some views of the lunar surface done by Paul - watch this space!
Our other interest is
astronomy, and when we can get a good clear night, we observe with our our binoculars, or our two telescopes, the Tasco, and the Orion. We are into observing the solar
system, and the Sun, as apposed to Deep Sky
observing, which we do, occasionally, but you must have a very clear night, and
we have observed the M15 and Andromeda Glaxies, on
occasion but our main love, is of course the planets, Mars, Jupiter, Saturn,
and the Moon. But we haven't observed with our binoculars and the telescopes
for quite some time. Paul dismantled the Tasco
telescope, during 1998, but he has still retained the mirror.
I saw some of the Total
Eclipse during 1999, but due to problems with my health, I was only able to see
it depart, but Paul insisted that was more relevant and more significant, than
seeing the Total Eclipse at its peak and we were also fortunate enough to see
another eclipse during January 2001, and during 2001, Paul did some sun
spotting, via his Orion telescope, but as he took up playing Classical Guitar
as a hobby during 1998, we are more or less completely out of sync, where our
hobby with astronomy is concerned, at this point in time, and you really have
got to rely on a good clear night to observe, when it actually comes down to
it, at the end of the day, but we will just have to wait and see exactly what
happens, where that is concerned, because when it actually comes down to it, at
the end of the day, that is all that you can do, isn't it?!
This article which was
written by Lynne Guy with additional comments by Daryl Ball was published in
The Junior Encyclopaedia Of Space, which was
featured, in The Inquisitor Red Dwarf Fanzine: Issue No 7: Christmas Issue 1997.
Additional
note by Lynne Guy.
I originally gleaned this
knowledge off Encarta 95's Astronomy section, which I printed off our second
computer, and I mailed it out to: The Inquisitor Red Dwarf Fanzine in
Northern Ireland, during November 1996, so I cannot claim the full credit for
this, and Daryl Ball who was editor of The Inquisitor Red Dwarf Fanzine,
contributed to this article for his Junior Encyclopaedia
Of Space section, which I think was marvellously
written, especially where his very witty comments, were concerned! And this
particular article in question actually exists in The Inquisitor Red Dwarf
Fanzine: Issue No 7: Christmas Issue 1997. And I have only got one copy of it
made, which will go into my Red Dwarf scrapbook, as soon as it is possible for
me to do so! But I haven't got the article up and running on our system, until
now, that is! And as I am into writing web pages, and as I have got an
Astronomy website, it might as well be uploaded on the site, rather than be
copied on to a new file in Microsoft Works, and therefore, people outside the
Inquisitor Red Dwarf Fanzine in Northern Ireland, will be able to have a look
at it, and express their views, via the newsgroups, for future reference!
More information to be
added to this article, at a later date!
JUPITER
Well, School Chum's, Thickie's, and Smegheads, here we
are again, with yet another exciting and informative edition of the 'Junior Encyclopaedia Of Space'. Well
actually it's just basically stuff we've copied out of said textbook, and on to
this wonderful page! The thing's you have to admit at Christmas time, just to
get a few pressies. I bet you all thought that I
wrote this stuff myself? No!! Oh well!! Since this IS the Christmas
Issue, I've decided to pick something BIG to discuss (No, it isn't my
ego.. ..tho if there is
anything bigger I wanted it hunted down and shot immediately!!)..... JUPITER.
Jupiter was named after the
chief of the Roman Gods (What do you mean, what was his name!!!), by ancient
astronomers. With a diameter of 89,000 miles, it's larger than all the other
planet's combined (A bit like my ego!!), although it's still only one tenth the
diameter of the sun. (No around the world in 80 day's here then....more like
800!!) Jupiter's huge globe could swallow up 1,300 bodies of the volume of
Earth, but has a mass, which only 318 time that of Earth, because Jupiter is
much less dense. From the outer layer's
and possibly as far as the presumed small hot rocky core, the main constituent
is hydrogen. The outer core of liquid hydrogen with metallic properties, caused
by the great pressure is surrounded by an outer envelope of liquid hydrogen
with some helium, and finally wrapped in an atmosphere of hydrogen, helium,
methane and ammonia gases. Many complex chemical compounds may be formed,
dyeing the belts in many different colours. Although
Jupiter radiates nearly twice the heat it receives from the Sun, it's core temperature is too low
for nuclear reactions to begin.
On the planets
surface, there is a structure that we call 'The Great Red Spot' (No
explanations required there I think!!). For many years it was believed that
this might be an island floating in Jupiter's atmosphere. It has now been
discovered by spacecraft sent to the planet that it is actually whirling around
in convective motion. The motion is anticyclonic,
like the air around high pressure areas in the Earth's atmosphere, which moves
counterclockwise in the Southern hemisphere, as does the Great Red Spot in
Jupiter's Southern hemisphere.
Jupiter is a mean distance
of 483,600,000 miles from the Sun and takes a period of 11.86 years to complete
a full rotation of the Sun. (Which would make me only about two and a half
years old?!) The quick rotation period, which is less than 10 hours (Dizzy, I'm
so dizzy, my head is spinning......like......a......whirlpool......! Oh sorry,
forgot where I was for a moment!!) means that the
equator tends to bulge out more, flattening the poles, and various features can
be seen to shift across the planet, even over a period of a few minutes.
The planet has a strong
gravitational pull and a strong Jovian magnetic field, which is tilted even
more than our Earth's to the axis of rotation. (Earth's -
23.5' Jupiter's 3.1' - axis of rotation that is!!). The magnetosphere is
streamlined in the solar wind with a bow shock front toward the Sun and a huge
magnetic tail at the nightside. (Is it me, or is this
getting bloody difficult to keep up with!! Well for all you Einstein's still
keeping up and the other 1% who haven't fallen asleep yet! (All
none of you!!) I'll continue!!) The magnetosphere of Jupiter encloses a plasma of charged particles. This plasma is incredibly
hot, (What hotter than the curry I had for breakfast - cornflakes vindaloo?!!), hotter even than the Sun, (No sunbathing
allowed on this planet then, I guess!!), but has a very low density, Jupiter's
strong radio bursts may be generated in it's
magnetosphere and triggered by perturbations from the passage of Io and other
inner satellites.
Jupiter has sixteen
satellites, amongst them Europa, Ganymede, Amalthea, Io and Callisto. Amalthea is the innermost of these, but one we all know
best is Io, the birthplace of everyone's favourite smeghead! Though terraforming
this particular satellite must gave been real fun,
since many volcanic eruptions occur on Io every year, flinging debris into a
ring, reminiscent of a smaller version of the one found around Saturn.
(Obviously they must have turned down the heating!!)
Many spacecraft have been
sent to Jupiter (Unmanned of course, I mean what self respecting astronaut
would want to come here for a holiday?! For a start, with an atmosphere of
hydrogen, helium, methane and ammonia, not only would you get your lungs dry
cleaned, you'd also end up speaking in an unnaturally high-pitched, squeaky
voice all the time, tho with some of the people I
know, you wouldn't notice the difference!!!). The first, Pioneer 10 (Makes you
wonder what happened to the first 9?!), was launced
in the 1970's and having reached Jupiter was flung out of the solar system by
its huge gravitational pull. The second, Pioneer 11 went on to survey Saturn
too, before departing our system. More on that, next
issue......maybe!!!
Well, that's your lot for
this issue. For those of you still awake, I've added a fabulous pic/photo of Jupiter (This is in The Inquisitor Red Dwarf
Fanzine: Issue No 7: Christmas Issue 1997, only! I intend to upload a
photograph of Jupiter on this web page, at a later date - Lynne Guy) to said
article and even marked Io on it for you. It's the tiny white dot, which can be
seen against Jupiter's surface! The other one further out is Europa. (We're just toooo good to
you lot......still it is Christmas, so everyone should be full of the Christmas
Spirit!! I'm looking forward to tucking into my share as soon as I've finished
this!!) As it's Christmas, I've even resisted the
temptation to slap in the first pic of a planet I can
find (As I did with the last issue. Did anyone notice? Nah!! Well, that's
okay then....got away with that okay, so I'll be able to use it again in the
future.....though I guess everyone above the age of three, might just have
noticed, in this case!!), and actually used a real photo of Jupiter, instead.
Anyway, till next time,
S.M.A.K.I.B.B.F.B (And old cliche', but still, a damn
good one!)!
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