Gerald Fitzgerald
November 4, 2002
Physics 1411, Section 8250
Jeff Howard
canismajor@hotmail.com
The Orion Group presents
NEPTUNE, PLUTO and QUAOAR
___________________________
NEPTUNE

NEPTUNE, THE PERSONALITY
The Greeks called him Poseidon, and he was the great god of the sea and of earthquakes, and
in that part of the world, they had plenty of both. But when the Romans took over, they
would not be outdone – they renamed every god they could find,
and Poseidon became Neptune.
He was the brother of Jupiter (Zeus) and of Pluto (Hades). After
the defeat of their father Saturn (Cronos), who had a nasty habit
of eating his children, the three brothers divided the world into
three parts -- Jupiter took the sky, Neptune the sea and Pluto the
underworld.
“What was that you said
about my mother??!”
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Neptune had a violent temper. He was a powerful, bearded man
holding a trident, seated in a magnificent seashell drawn by seahorses, commanding terrifying forces of nature, able to unleash
devastating storms and earthquakes if he was in a foul mood.
When he wanted something, by God he got it! One day, for
example, he happened to see a water nymph named Amphitrite
dancing naked on an island somewhere, and never one to do
anything halfway, instantly fell in love with her. He asked her to
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marry him but she refused.
Neptune sent one of his servants, a dolphin, to find her and persuade her otherwise, which he
did. She changed her mind and married the sea god. As a reward for helping him win the
heart of the fair Amphitrite, Neptune named the constellation “Delphinus” in honor of the
dolphin. Neptune and Amphitrite had several children. Among them was Triton, whose
name was given in 1846 by William Lassell to the principal moon of the planet Neptune.
NEPTUNE, THE CONTROVERSY
The discovery of Neptune represents one of the most controversial episodes in the history of
British science. It concerns the failure of British astronomers to discover the planet despite
the existence of calculations that predicted its existence.
In 1781, Sir William Herschel used a telescope to discover the planet Uranus. It was the first
“modern” planet, that is, the first planet not known since ancient times, because it is too faint
to be noticed with the naked eye. Its discovery doubled the size of the known Solar System
practically overnight. Herschel received Royal patronage for his sensational discovery, and
with it, built the biggest and best telescopes in the world, with which he and his son John
surveyed the northern and southern skies.
Isaac Newton's theory of gravitation, and Edmond Halley's use of it to predict the return of
the famous comet that now bears his name, had explained the physics of the heavens.
Against this background, it seemed as if Britain had established almost “proprietorial” rights
to celestial discoveries.
In 1845, a Cambridge mathematician, John Couch Adams, predicted the existence of an
unseen planet to account for the fact that Uranus was being pulled slightly out of position in
its orbit. Adams attributed this pull to the gravitational
effect of an unknown body, and calculated its position.
Adams visited the Royal Observatory at Greenwich to
present his findings to the Astronomer Royal, Sir George
Airy, the top scientific civil servant of his day. But Airy
was unavailable, and although Adams left a note of his
calculations, Airy took little interest, believing that the
Royal Observatory should not be diverted from its publicly
funded work on timekeeping and navigation, in which it
was world leader, to search for new planets.
“There it is! No, wait, THERE
it is! I saw it a minute ago!”
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It wasn’t until a French mathematician, Urbain Leverrier,
published a similar prediction that Airy decided to take
action. Not to be outdone by those “French rivals,” he
asked Professor James Challis at Cambridge University to
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begin a search. Challis began in July 1846 and actually sighted the new planet four times
without recognizing it! Meanwhile, Leverrier had enlisted the help of astronomers at Berlin
Observatory, who found the new planet on the night of September 23, 1846.
When it became known that Airy and Challis had let the French and Germans beat them to
the discovery, they found themselves at the center of a national scandal.
NEPTUNE, THE PLANET
Neptune is the outermost planet of the gas giants, with an equatorial diameter of 30,760
miles. If it were hollow, it would contain nearly 60 Earths. It orbits the Sun every 165 years.
It has eight moons, six of which were found by Voyager in 1989. A Neptunian day lasts for
16 hours and 6.7 minutes.
Even though Neptune is four times larger than Earth, its surface gravity is nearly identical.
This is probably due to the fact that it is composed mostly of gas. The first two thirds of
Neptune is composed of a mixture of molten rock, water, liquid ammonia and methane. The
outer third is a mixture of heated gases comprised of hydrogen, helium, water and methane.
Methane gas is what gives Neptune its characteristic blue color.
The cloud patterns of Neptune's methane atmosphere are the same as all the gas giants, with
several giant storms, including the largest, the Great Dark Spot, similar to Jupiter's Great Red
Spot, which at the time of its discovery was the size of Earth (it has since dissipated). The
structure of the atmosphere, as on Earth, consists of a troposphere, stratosphere, mesosphere,
and thermosphere. Voyager detected a small, oddly-shaped, eastward-moving cloud orbiting
Neptune every 16 hours or so. This “scooter” as it was named was thought to be a plume
rising above a deeper cloud deck.
This image shows bands of sunlit cirrus-like clouds in
Neptune's northern hemisphere. These clouds cast
shadows on the blue cloud deck 35 miles below. The white
streaky clouds are from 30 to 100 miles wide and extend
for thousands of miles.
Neptune has the strongest winds of any planet, most of them blowing westward, opposite to
Neptune’s rotation. Near the Great Dark Spot, winds have been estimated at up to 1,200
miles an hour.
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Neptune’s magnetic field, like that of Uranus, is highly tilted at 47 degrees from the planet’s
rotation axis and offset at least 8,500 miles from the physical center. The planet actually
appears to roll rather than spin in its orbit around the Sun.
The Hubble Space Telescope is allowing astronomers to study Neptune's dynamic
atmosphere with a level of detail not possible since the 1989 flyby of the Voyager 2 space
probe. Building on Voyager's initial discoveries, Hubble is revealing that Neptune has a
remarkably dynamic atmosphere that changes over just a few days.
The temperature difference between Neptune's strong internal heat source and its frigid cloud
tops (-260° Fahrenheit) might trigger instabilities in the atmosphere that drive large-scale
weather changes. In addition to hydrogen and helium, the main constituents, Neptune's
atmosphere is composed of methane and hydrocarbons, like ethane and acetylene.
Neptune’s Vital Statistics
Atmospheric composition
Hydrogen
Helium
Methane
Atmospheric pressure (bars)
1-3
Average Cloud Top Temperature (K):
63 o K
Density:
1,638 kg/m3
Diameter:
49,493 kilometers (30,760 miles)
Equatorial escape velocity (km/sec)
23.50
Equatorial radius (Earth = 1)
3.8799
Equatorial radius (km)
24,746 kilometers
Equatorial surface gravity (m/sec^2)
11.0
Magnitude (Vo)
7.84
Mass:
102.4 x 1024 kilograms (17.2 x Earth’s)
Maximum Distance from Sun:
4.54 billion kilometers (2.82 billion miles)
Mean cloud temperature
-193°C to -153°C (-315.4°F to –243.4°F)
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85%
13%
2%
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Mean density (gm/cm3)
1.64
Mean distance from the Sun (Earth = 1)
30.0611 AU
Mean distance from the Sun
4,504,300,000 kilometers
Mean orbital velocity (km/sec)
5.45
Minimum Distance from Earth:
4.3 billion km (2.68 billion miles)
Minimum Distance from Sun:
2.446 billion km (2.77 billion miles)
Orbital eccentricity
0.0097
Orbital inclination
1.774 degrees
Orbital period
164.79 years
Orbital Semimajor Axis:
30.07 AU (Earth’s = 1 AU)
Revolution Period about the Sun:
165 years
Rotation Period about Axis:
17.24 hours
Rotational period
16.11 hours
Satellites/Rings:
8 known moons, faint rings
Surface Gravity:
11 m/s2 (1.12 x Earth's)
Temperature at Cloud Tops:
-210°C (-346°F)
Tilt of Axis
29° 36”
This picture of Neptune was taken by Voyager 2 on August 20,
1989. It shows the Great Dark Spot near the center, at 22
degrees south and circuits Neptune every 18.3 hours. The bright
clouds to the south and east of the Great Dark Spot constantly
change their appearances in periods as short as four hours.
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Scientists deduce Neptune’s internal structure by
observing its radius, mass, period of rotation, the shape
of its gravitational field and the behavior of hydrogen,
helium, and water at high pressure. This cutaway view
visualizes Neptune composed of an outer envelope of
molecular hydrogen, helium and methane. Below this
region, Neptune appears to be composed of a mantle
rich in water, methane and ammonia. These elements
are under high temperature and pressure.
An almost true-color picture of Neptune and Triton taken
with the Hubble Space Telescope. The south pole is to the
lower left. The picture reveals a bright cloud feature at the
south pole, near the bottom of the image, with bright cloud
bands at 30° South and 60° South latitude and a bright
cloud band near 30° N latitude.
These images were taken 9 hours apart to show the
differences in cloud formation in each hemisphere. The
colors are almost spot-on.
These Hubble Space Telescope views of Neptune provide
three views of changing weather conditions. The images
were taken in 1994 on October 10 (upper left), October 18
(upper right), and November 2 (lower center), when
Neptune was 2.8 billion miles from Earth.
In 1994, the HST discovered a new Great Dark Spot,
located in the northern hemisphere. The spot is nearly
identical to the one in the southern hemisphere that was
discovered in 1989 by Voyager 2. This image was taken
on November 2, 1994 with Hubble's Wide Field Planetary
Camera 2, when Neptune was 2.8 billion miles from
Earth. Hubble can resolve features as small as 625 miles
(1,000 kilometers) across in Neptune's cloud tops.
Also in 1994, Hubble showed that the southern dark spot had disappeared.
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Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses
that have been pushed to higher altitudes where they cool to form methane ice crystal clouds.
The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the
atmosphere.
Planetary scientists can’t say how long this new spot will last. But the high resolution of the
Hubble telescope will allow astronomers to follow the spot's evolution and continued
development.
This is one of the final images from Voyager 2. Triton appears at the
bottom right. The image was taken on August 31, 1989.
NEPTUNE’S RINGS
Neptune’s four rings are narrow and faint, made of dust particles thought to have been made
by tiny meteorites smashing into Neptune's moons.
The following table is a summary of the rings of Neptune.
Name
Distance*
Width
Thickness
Mass
Albedo
1989N3R
41,900 km
15 km
Not yet known
NYK
low
1989N2R
53,200 km
15 km
Not yet known
NYK
low
1989N4R
53,200 km
5,800 km
Not yet known
NYK
low
1989N1R
62,930 km
Less than 50 km
Not yet known
NYK
low
*The distance is measured from the planet center to the start of the ring.
These two 591-second exposures of the rings of Neptune
were taken by Voyager 2 on August 26, 1989 from a
distance of 174,000 miles. The two main rings are fully
visible. You can also see a faint inner ring at about 25,000
miles from the planet. Neptune itself is over-exposed in
the center of the picture, which was necessary in order to
capture the delicate ring images.
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NEPTUNE’S MOONS
This table summarizes the radius, mass, distance from the planet center, discoverer and the
date of discovery of each of the moons of Neptune:
Moon
Naiad
Thalassa
Despina
Galatea
Larissa
Proteus
Triton
Nereid
#
III
IV
V
VI
VII
VIII
I
II
Radius
(km)
29
40
74
79
104x89
200
1,350
170
Mass
(kg)
unknown
unknown
unknown
unknown
unknown
unknown
2.1422
unknown
Distance
(km)
48,000
50,000
52,500
62,000
73,600
117,600
354,800
5,513,400
Discoverer
Date
Voyager 2
Voyager 2
Voyager 2
Voyager 2
Voyager 2
Voyager 2
W. Lassell
G. Kuiper
1989
1989
1989
1989
1989
1989
1846
1949
TRITON
Triton (“TRY-ton”) is the seventh and largest of Neptune's satellites.
In Greek mythology, Triton was a god of the sea, the son of Poseidon (Neptune). He is
usually portrayed as having the head and trunk of a man and the tail of a fish.
Triton was discovered by Lassell in 1846, only a few weeks after the discovery of Neptune
itself.
Triton has been visited by only one spacecraft, Voyager 2, on
August 25, 1989. Almost everything we know about it comes from
this encounter.
Triton! Looks sort
of like the egg in
“Alien”.
Triton's orbit is retrograde, which means that it orbits Neptune in a
direction opposite to the rotation of the planet. It is the only large
moon in the Solar System which orbits “backwards.” The only other
moons with retrograde orbits are Jupiter's moons Ananke, Carme,
Pasiphae and Sinope and Saturn's Phoebe, all of which are less than
1/10th the diameter of Triton.
Triton could not have condensed from the primordial Solar Nebula
in its current configuration. It must have formed elsewhere (perhaps
in the Kuiper Belt?) and later been captured by Neptune (perhaps involving a collision with
another Neptunian moon, now shattered). A capture scenario could account not only for
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Triton's orbit, but also for the unusual orbit of Nereid and provide the energy needed to melt
and differentiate Triton's interior.
Because of its retrograde orbit, tidal interactions between Neptune and Triton remove energy
from Triton’s momentum, thus lowering its orbit. At some time in the distant future, it will
either break up (perhaps forming a ring) or crash into Neptune. Wouldn’t you like to be
around to see that!
Triton has an unusual axis of rotation, tilted 157 degrees with respect to Neptune's axis
(which, in turn, is inclined 30 degrees from the plane of Neptune's orbit). This adds up to an
orientation with respect to the Sun somewhat like Uranus's, with polar and equatorial regions
alternately pointing toward the Sun. This probably results in radical seasonal changes as one
pole and then the other moves into the sunlight. During the Voyager 2 encounter, Triton's
south pole was facing the Sun.
Triton's density (2.0) is slightly greater than that of Saturn's icy
moons (e.g. Rhea). Triton is probably only about 25% water ice
with remainder rocky material.
Voyager found that Triton has an atmosphere, albeit a very
tenuous one (about 0.01 millibars), composed mostly of nitrogen
with a small amount of methane. A thin haze extends up from 3 to
6 miles.
The temperature at the surface of Triton is only 34.5 K (-235 C, 391 F), as cold as Pluto. This is due in part to its high albedo (.7 to .8), which means that
little of the Sun's meager light is absorbed. At this temperature, methane, nitrogen and
carbon dioxide all freeze solid.
There are very few craters visible. Triton’s surface is relatively young. Almost the entire
southern hemisphere is covered with an "ice cap" of frozen nitrogen and methane.
There are extensive ridges and valleys in complex patterns all over
Triton's surface. These are probably the result of freezing/thawing
cycles.
The most interesting (and totally unexpected) features of this
interesting world are the ice volcanoes. The erupting material is
probably liquid nitrogen, dust, or methane compounds from under
the surface. One of Voyager's images shows an actual plume rising
5 miles above the surface and extending 87 miles “downwind”
(left).
Ice volcanoes on
Triton.
Triton, Io and Venus are the only bodies in the solar system besides
Earth that are known to be volcanically active. (Mars was in the
past). It's also interesting to note that very different volcanic processes occur in the outer
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solar system. Earth’s, Venus’ and Mars’ eruptions are/were of rocky material and are/were
driven by internal heat. Io’s eruptions are probably sulfur or sulfur compounds driven by
tidal interactions with Jupiter. Triton’s eruptions are of very volatile compounds like
nitrogen or methane driven by seasonal heating from the Sun.
Triton’s Vital Statistics:
Diameter
2700 kilometers
1677.7 miles
Equatorial radius (Earth = 1)
0.21167
Equatorial radius
1,350 kilometers
Escape velocity (km/sec)
1.45
Magnitude (Vo)
13.47
Mass (Earth = 1)
3.5810-3
Mass:
2.1422 kg
Mean density (gm/cm3)
2.07
Mean distance from Neptune
354,760 kilometers
220,438 miles
Mean orbital velocity (km/sec)
4.39
Mean surface temperature
-235°C (-391°F)
Orbital eccentricity
0.0000
Orbital inclination
157.35 degrees
Orbital period
5.87685 days
Rotational period
5.87685 days
Visual geometric albedo
0.7
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NEPTUNE, THE MYSTIC
It was no accident that Gustav Holst gave this name to the final movement of his “Planets”
Symphony. Neptune has always been regarded as mysterious, transcendental and
supersensory – opening doors to mystical experiences. Astrologically, Neptune governs
illusions and false appearances, dealing with drug use and all kinds of pseudo-realities.
Neptune’s equivalent Zodiac sign is Pisces, commonly known as the “dustbin of the Zodiac.”
Whereas the other 11 signs have rather distinct characteristics, Pisces is considered to be the
most enigmatic, the hardest to pin down – blending perfectly with deep, dark Neptune. It
rules over the oppressed and the abandoned – the misfits of society.
Yet, while Neptune is the planet of deception and secrets, it is also the planet of spiritual
enlightenment. On a higher level it rules visionaries, and those who are glamorous and
charismatic. It represents spirituality, mysticism and ideals.
On a personal level, Neptune's house position and its aspects with other planets in a chart will
describe spirituality, abstract thinking, illusion, disillusionment, and areas of a person’s life
where things aren't always what they seem. It rules derangement, guilt, persecution and
describes the potential for experiences related to confinement, abandonment, addiction or
physical intolerance to drugs and alcohol.
Neptune, as one of the outer, transpersonal planets, spends about thirteen years in each sign,
taking around 164 years to move through all twelve signs. Since 164 years pass between
separate people born during its transit of one sign and those born when it returns, Neptune's
significance in any sign is described as generational or historical.
Gerald Fitzgerald
October 26, 2002
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PLUTO

PLUTO, THE MYTH
Pluto is the Roman name for the God of the Underworld the Greeks called “Hades.” The
Place which bore his name (the Underworld, or Earth) was left over after Zeus claimed the
sky and Poseidon got the sea. He has been perceived in many guises, both Good and Evil –
but in every case, he is seen as Dark and Mysterious.
In the famous story “The Abduction of Persephone,” he is
depicted as the Bad Guy, intent on possessing the innocent
mortal Persephone. He happens along one day, sees her picking
flowers with some friends, minding her own business, and drags
her into the ground for his own to rule the Underworld by his
side.
Guarded by Cerberus, Hades the Place was usually depicted as
underground and was separated from the land of the living by
five rivers. One of these was the River Styx, across which the
dead were ferried. Three judges decided the fate of souls –
heroes went to the Elysian Fields, while evildoers went to
Tartarus. The Underworld was a place for both saints and
sinners, with Hades serving as the Innkeeper.
In various adventures, Hades abducted the maiden Persephone,
tricked the heroes Theseus and Peirithous and managed to get
himself handcuffed by Sisyphus. He was a dreaded figure to
mortals, who were very careful about how they swore oaths in
his name. To many people, simply to utter the word “Hades”
was a frightening proposition – so people began to make up
euphemisms, or words that meant the same thing but with a
more pleasant sound.
“Bernini’s Abduction of
Persephone” as
interpreted by Anime
artist Died.
Since all precious minerals came from the Earth (the dwelling place of Hades), and since the
god was indeed wealthy when it came to the number of subjects in his kingdom, people
started referring to “Plouto’s” wealth. This accounts for the name given to him by the
Romans, who also called Zeus Jupiter, Ares Mars and Hermes Mercury. Hades became
Pluto.
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When the Greeks prayed to Hades, they banged their hands on the ground to be sure he
would hear them. Black animals, such as sheep, were sacrificed to him, and it is believed
that at one time even human sacrifices were offered. The blood from sacrifices to Hades
dripped into a pit so it could reach him. The person who offered the sacrifice had to turn
away his face. Every hundred years festivals were held in his honor, called the Secular
Games.
PLUTO, THE DISCOVERY
The story of Pluto's discovery begins with Percival
Lowell, the founder of Lowell Observatory in
Flagstaff, Arizona. He was obsessed with the notion of
a "trans-Neptunian" planet, which he believed could be
detected from the effect it supposedly had on Neptune's
orbit.
In 1846, Neptune had been discovered because of
irregularities in the orbit of Uranus. Based on this
evidence, Lowell founded an observatory and funded
two unsuccessful searches for the mysterious “Planet
X,” taking photograph after photograph and bending
over a table for many long hours comparing them,
checking for the slightest possible difference, or
planetary movement. Years went by and he found
nothing.
Clyde Tombaugh at age 22 with his
homemade telescope. No, he did
NOT use it to discover Pluto!
Lowell died suddenly in 1916, never having found
what he was looking for, and it wasn’t until many
years later that his heirs were able to get the
observatory up and running again. For a third search, observatory director Dr. Vesto Slipher
hired a young man from Kansas, Clyde W. Tombaugh, to carry on Lowell’s painstaking
work.
Tombaugh systematically took pictures of the plane of the solar system, specifically, in the
area of the constellation of Gemini. He took pictures in pairs, one or two weeks apart, and
looked for anything that moved. The idea is that planets would appear to shift against the
backdrop of stars because the earth had moved to a new viewing angle over the intervening
two week period.
On February 18, 1930, Clyde Tombaugh became the first and only American to discover a
planet.
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Now you think you see it, and now – now you think you see it again! Pluto transiting Delta Geminorum
as seen by Clyde Tombaugh in 1930.
Pluto was discovered by a fortunate accident. Calculations which later turned out to be in
error had predicted a planet beyond Neptune, based on the motions of Uranus and Neptune.
Not knowing of the error, Tombaugh did a very careful sky survey in which turned up Pluto
anyway. He found Pluto in Gemini, which is a much more sparsely populated (and easier to
search) section of the sky than Taurus – where Lowell was looking.
The planet received its name (after many other suggestions) perhaps because it's so far from
the Sun that it is in perpetual darkness and perhaps because "PL" are the initials of Percival
Lowell. “Pluto” is the perfect name.
PLUTO, THE PLANET
Pluto is generally the farthest planet from the Sun (with the occasional exception of Neptune)
and is by far the smallest, with a diameter of only 1413 miles. Mercury, previously thought
to be the smallest, is more than twice as large! Pluto is smaller than seven of the solar
system's moons (the Moon, Io, Europa, Ganymede, Callisto, Titan and
Triton).
Pluto is the only planet that has not been visited by a spacecraft. Even the
Hubble Space Telescope can resolve only the largest features on its
surface. Pluto is the second most photographically “contrasty” body in the
Solar System (after Iapetus), meaning that the range between the
brightness of its bright areas and the darkness of its dark areas is so great,
that the planet truly stands out among all the worlds of the Solar System.
Pluto rotates in the opposite direction from most of the other planets. It is locked in a 3-to-2
resonance with Neptune – which means its orbital period is exactly 1.5 times longer than
Neptune's. Its orbital inclination is also much higher than the other planets. Thus though it
appears that Pluto's orbit crosses Neptune's, it really doesn't and they will never collide.
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Like Uranus, the plane of Pluto's equator is at almost right angles to the plane of its orbit,
which gives its orbit the previously-mentioned “rolling” effect.
The surface temperature on Pluto is not well known but is probably between 35 and 45
Kelvins (-228° to -238° C, or –378.4° to –396.4° F).
Pluto's composition is unknown, but its density (about 2 gm/cm3) indicates that it is probably
a mixture of 70% rock and 30% water ice, much like Triton. The bright areas of the surface
seem to be covered with ices of nitrogen with smaller amounts of solid methane and carbon
monoxide. The composition of the darker areas of Pluto's surface is unknown, but may be
due to primordial organic material or photochemical reactions driven by cosmic rays.
Imagine what an interesting world it would be if it existed within our biosphere!
Little is known about Pluto's atmosphere, but it probably consists
of frozen nitrogen with some carbon monoxide and methane. It is
extremely tenuous – the surface pressure being only a few
microbars. Pluto's highly-eccentric orbit places it at times closer
to the Sun than Neptune – as close as 30 AU – and at perihelion,
Pluto's atmosphere may actually exist as a gas, and it is possible
that some of the atmosphere escapes into space – perhaps even
interacting with Charon. But the thin atmosphere freezes and falls
to the surface again as the planet moves away from the Sun.
NASA plans to launch a spacecraft, the Pluto Express, that will
allow scientists to study the planet before its atmosphere freezes.
Pluto and Charon
Some scientists believe that Pluto should be classified as a large asteroid or comet instead of
a planet. Some consider it to be the largest of the Kuiper Belt objects. There is some
evidence to support the latter position, but Pluto has always been classified as a planet and is
likely to remain so.
The unusual nature of the orbits of Pluto and of Triton and the
similarity of bulk properties between Pluto and Triton suggest
some historical connection between them. It was once thought
that Pluto may have once been a satellite of Neptune's, but this
now seems unlikely. A more popular theory is that Triton, like
Pluto, once moved in an independent orbit around the Sun and
was later captured by Neptune.
The sum of the masses of Pluto and Charon have been
determined from careful measurements of the period and radius
of their orbits and Kepler's Third Law – however, the individual
masses of Pluto and Charon are difficult to determine because
that requires determining their mutual motions around the center of mass of the system,
which requires much finer measurements.
Pluto & Charon again.
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Pluto and Charon are so small and so far away that even the Hubble Telescope has difficulty.
The ratio of their masses is probably somewhere between 0.084 and 0.157. More
observations are underway but we won't get really accurate data until a spacecraft is sent.
Pluto’s Vital Statistics
Atmospheric composition
N2, CH4, CO
Nitrogen, Methane, Carbon Monoxide
Average distance from Sun
39.5 Astronomical Units
Density
1.92 to 2.06 gm/cc
Equatorial escape velocity (km/sec)
1.22
Equatorial radius (Earth = 1)
0.1783
Equatorial radius (km)
1,137 kilometers
Equatorial surface gravity (m/sec2)
0.4
Magnitude (Vo)
15.12
Mass (kg)
1.27e+22 kilograms
Mean density (gm/cm3)
2.05
Mean distance from the Sun (Earth = 1)
39.5294 AU
Mean distance from the Sun (km)
5,913,520,000 kilometers
3,674,490,972.7 miles
Mean orbital velocity (km/sec)
4.74
Orbital eccentricity
0.2482
Orbital inclination (degrees)
17.148
Orbital period around Sun (years)
248.54
Radius
1145 to 1200 km
711.5 to 745.7 miles
Rotation period
6.39 days
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Rotational period (days)
6.3872
Surface composition
H2O, N2, CH4, CO ices
Water, Nitrogen, Methane, Carbon Monoxide
Surface temperature
40° Kelvin (-233° C or –387.4° F)
Tilt of axis (degrees)
122.52
Tilt of spin axis relative to ecliptic plane
119.6 degrees
Visual geometric albedo
0.3
Here Pluto and Charon are displayed side-by-side,
not in their proper orbital configuration. Pluto's
north pole is at the top of the image and each panel
shows the two rotated by approximately 90
degrees. Pluto and Charon are tidally locked in
their orbit around one another. Standing either on
Pluto or Charon, you would always see the same
face if you are on the side toward the other body.
The squares you see in the maps are not real, but
are caused by the computer processing. The face
of Pluto you see here is the hemisphere that always
faces Charon – at the same time, you are seeing the
side of Charon that faces away from Pluto.
CHARON
Charon (pronounced “Karen”) is Pluto's lone satellite.
It was discovered in 1978 by James W. Christy at the U.S. Naval Observatory. Like Pluto,
its name has a double meaning. It is officially named for the mythological figure who ferried
the dead across the River Styx into Hades (the Underworld). Unofficially, Christy named it
in honor of his wife, Charlene. Thus, people “in the know” pronounce it with the first
syllable sounding like “shard” (“SHAHR-en”).
Its edge-on orbital plane made it possible to observe many transits of Pluto over Charon and
vice-versa. By carefully calculating which portions of which body would be covered at what
times, and watching brightness curves, astronomers were able to construct a rough map of
light and dark areas on both bodies. Prior to 1978, it was thought that Pluto was much larger
since the images of Charon and Pluto were blurred together.
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Charon is unusual in that it is the largest moon with respect to its primary planet in the Solar
System (a distinction once held by Earth's Moon). It is so large that some prefer to think of
the Pluto/Charon system as a double planet rather than a planet and a moon.
Charon's radius is not well known. JPL's value of 586 has an error
margin of +/-13, more than two percent. Its mass and density are also
not well known.
Pluto and Charon are also unique in that not only does Charon rotate
synchronously but Pluto does, too – they both keep the same face
toward one another. (This makes the phases of Charon as seen from
Pluto very interesting.)
Charon's composition is unknown, but its low density (about 2 gm/cm3) indicates that it may
be similar to Saturn's icy moons (i.e. Rhea). Its surface seems to be covered with water ice.
Unlike Pluto, Charon does not have large albedo (reflective) features, but it may have smaller
ones that have not yet been resolved.
Charon’s Vital Statistics
Density
1.51 to 1.81 gm/cc
Equatorial radius (Earth = 1)
9.19-02
Equatorial radius (km)
586 kilometers
Escape velocity (km/sec)
0.610
Magnitude (Vo)
16.8
Mass (Earth = 1)
3.188-04
Mass
1.9021 kilograms
Mean density (gm/cm3)
1.83
Mean distance from Pluto
19,640 kilometers
Mean orbital velocity (km/sec)
0.23
Orbital eccentricity
0.00
Orbital inclination
98.80 degrees
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Orbital period around Pluto
6.38725 days
Radius
600 to 650 km
372.8 to 403.9 miles
Rotational period
6.38725 days
Surface composition
H2O ice
Visual geometric albedo
0.5
PLUTO IN ASTROLOGY
Pluto is the slowest moving body in astrology and its influence is transformational but slow - deep and often hidden. Pluto rules the intense and secretive sign of Scorpio, with its
attachment to the shadows and the bottom-line truth. It has no fear of confronting life or
death, positive or negative, and it seeks to make us more complete, more whole and more
empowered by nudging us to acknowledge the many different facets of life.
Astrologer Danielle A. Ricard describes Pluto as “raw energy -- cataclysm, disaster and
annihilation, as well as ecstasy, monetary windfalls, revolution, rebirth and renewal. He
represents what we both fear and desire -- the cycle of life, death and rebirth, the secrets of
the universe, the occult mysteries, the explosive interplays between men and women, the
miracles of life.”
According to Linda Rankin, it “creates fears, to make us strong when we crash through them
-- hides in shadows and tempts us to find it -- makes us feel weak, so that we can grow
powerful. It promises unimaginable power that arrives in the smallest packages.”
Pluto encompasses all the most powerful forces of man and nature. It was under the
generational influence of Pluto that we split the atom and discovered nuclear fission – it was
no accident that one of the most powerful substances known to Man should be named
“Plutonium.”
Its discovery coincides with the Great Depression.
Occupations associated with Pluto include: Nuclear scientists, engineers, archeologists,
insurance agents and adjusters.
Pluto rules over: Plutonium, bloodstone, dark red agate, alimandine and pyrope garnets.
Pluto’s colors are black and deep red.
In the body, Pluto rules over the reproductive organs and the gall bladder.
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The Sign in which Pluto falls in a person’s natal chart will apply to a generation of people
(12-30 yrs.), and therefore describes a trend in the cycles of evolutionary changes in
humanity – particularly in the use of power, force and sexuality. It also shows the ways in
which a person is intuitive, searching and powerful.
The House Placement of Pluto in a person’s chart (influenced by the time and place of your
birth) will determine in what area of your life you are most likely to make dramatic changes
within yourself. It also helps describe the way in which you use your personal power and
sexual energy, and what kind of energy or activities offer you an avenue for great personal
insight and growth.
Transiting Pluto takes from 12-33 years to pass through a Natal House. During that time
you may experience major life changes, or inner transformation, in a particular area of your
life.
Gerald Fitzgerald
October 26, 2002
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QUAOAR
I first read about Quaoar [“kwa-war”] on October 7th, 2002, when I received an Internet
bulletin about it in NASA’s Science News. The bulletin read, “Hubble Spots The Biggest
World Since Pluto.” I immediately copied the article into my e-mail and sent it to everyone
on my mailing list.
My friend Carol Streatfeild in Houston had a high-minded reaction: “Astrologers, throw
away your old charts!”
Brigitte Hill in Florida had this to say: “I bet land is really cheap there. Can you pick me up
a few thousand acres?”
But my friend Ben Schroth said it best: “Quaoar. What a rotten name for a planetoid.”
I really must concur. So much for Conventional Wisdom!
Back in June of 2002, Dr. Michael Brown and Chadwick Trujillo of the California Institute
of Technology used the Palomar Oschin Schmidt telescope (at Mount Palomar, California) to
discover Quaoar as an 18.5-magnitude object moving slowly across the constellation
Ophiuchus. Brown later did follow-up observations using Hubble's new Advanced Camera
for surveys on July 5 and August 1, 2002, to measure the object's true angular size of 40
milliarcseconds, corresponding to a diameter of about 800 miles. Only Hubble had the
sharpness needed to actually resolve Quaoar’s tiny disk, leading to the first-ever direct
measurement of the true size of a Kuiper Belt Object (KBO).
Brown and Trujillo reported their findings on October 7, 2002 at the 34th annual meeting of
the Division for Planetary Sciences of the American Astronomical Society in Birmingham,
Alabama. Their discovery gives important insights into the origin and dynamics of the
planets, and bodes well for clearing up some of the mystery surrounding the strange and
elusive Kuiper Belt beyond Neptune.
The Kuiper Belt is an icy debris field of comet-like bodies extending 7 billion miles beyond
Neptune's orbit, and includes Quaoar and Pluto. Over the past decade more than 500 icy
bodies have been found in the Kuiper Belt, and with a few exceptions, all have been
significantly smaller than Pluto.
In my initial reading about Quaoar, here are the basic facts I was able to discover:
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
Quaoar is the largest object found in the Solar System since Pluto in 1930.

Quaoar orbits the Sun at a distance of about 4 billion miles, more than a billion miles
further than Pluto. This disqualifies it as a candidate for the next planet beyond Pluto
according to Titius-Bode’s Law, which expects to find a planet orbiting at 77.2 AU, or
just over 7 billion miles.

Quaoar is greater in volume than all the asteroids combined.

Quaoar is smaller than Pluto.

Quaoar shines at less than 1/100,000ths the brightness of the faintest star seen by the
human eye. Even then, Quaoar is considered fairly bright for an object of its size and
distance.

Quaoar is the farthest object in the Solar System ever to be imaged by Earth astronomers.

Quaoar’s orbit around the Sun is circular, not elliptical like most planets.

Quaoar is approximately 800 miles in diameter, which makes it the largest object
discovered in the Solar System since 1930. Previously, the largest objects were Varuna
and 2002 AW197, two Kuiper Belt Objects both estimated to be 540 miles wide.

Quaoar takes 288 years to orbit the Sun.

Researchers suspect Quaoar is made mostly of low-density ices mixed with rock, not
unlike the makeup of a comet.
The question of whether or not Quaoar is to be considered a planet has yet to be addressed by
astronomers. In my opinion, Quaoar should follow the “Duck Rule” – if it moves like a
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planet, and it looks like a planet, and it’s built like a planet, then it’s a planet. It can’t be a
moon, so what else can it be?
Quaoar (also known as “2002 LM60”) hasn't
been officially named yet -- it's too new. The
International Astronomical Union will have to
make the final decision. Trujillo and Brown
suggested “Quaoar” after a creation god of the
Native American Tongva tribe – the original
inhabitants of the Los Angeles basin where
Caltech is located. According to legend, Quaoar
“came down from heaven, and, after reducing
chaos to order, laid out the world on the back of
seven giants. He then created the lower animals,
and then Mankind.”
Well, that’s good enough for me!
Quaoar! This Hubble image is actually a
composite of 16 separate exposures taken
I think it is interesting to note that one source I
with Hubble’s new Advanced Camera for
found on the Internet mentioned that the name
Surveys.
“Quaoar” was so sacred to the
Tongva/Gabrielino tribe who worshipped him,
that they seldom said the name out loud. Small wonder. I wonder if Brown and Trujillo
considered this!
Also, I would like to point out that, in my search for a likeness of the god Quaoar to use at
the top of this article, I spent several hours looking at nearly a hundred websites and was
unable to find a single one. Not a painting, not a sculpture, not a woodcarving. Either the
Tongva were not sophisticated in the arts, or they had no graphic representation of their chief
god. Quaoar is as mysterious on Earth as he is in space.
Eventually, Brown has predicted, KBOs even larger than Quaoar will be found, and Hubble
will play the most vital role in pinning down their sizes. In the meantime, Quaoar holds the
record – but only for now.
Still out there, somewhere past Quaoar – at 77.2 AU, if Titius-Bode’s Law is correct, there is
yet another planet waiting to be discovered – and God knows how many more comets,
planetoids and KBOs in between.
Gerald Fitzgerald
October 26, 2002
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Sources:
Forever FanArt Magazine, August 11, 2001
FrequentlyAsked Questions About Quaoar, Chad Trujillo at Caltech
Myths About Gods of Olden Cultures, Jo Edkins
The Nine Planets, Bill Arnett
Tongva Tovangar Yayakenar Tribal Dancers
Views of the Solar System, Calvin J. Hamilton
Welcome to the Planets, NASA
Wikipedia, the Free Encyclopedia
Windows to the Universe, University Corporation for Atmospheric Research (UCAR).
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