@database "Descriptive Chapters"
@remark Copyright © 1995, Syzygy Research & Technology Ltd. All rights reserved.
@node main "Description"
This database contains a series of descriptional chapters, linked into by other
documents. As a result, no table of contents exists for the file.
@endnode
@node object04100000ff "The Sun - Fast Facts"
@remark beginverbatim
Mass...............................1.9891e30 kg (332948 times that of Earth)
Equatorial radius.....................696000 km (109.12 times that of Earth)
Surface gravity..........................274 m/s^2 (27.9 times that of Earth)
Apparent @{"semidiameter" link define.guide/semidiameter} at 1 @{"AU" link define.guide/au}.........959.64 arcseconds
Average density.........................1.41 g/cm^3
@{"Inclination" link define.guide/inclination} of equator to @{"ecliptic" link define.guide/ecliptic}......7.25 degrees
@{"Magnitude, apparent" link define.guide/apparentmagnitude}....................-26.8
@{"Magnitude, absolute" link define.guide/absolutemagnitude}.....................4.77
Average surface temperature.............5500 degrees C
@{"Spectral classification" link define.guide/spectralclassification}.................G2-V
Age............................4,600,000,000 years
Expected life remaining........5,000,000,000 years
@{"Revolution" link define.guide/revolution} period in Milky Way...200,000,000 years
@{"Rotational" link define.guide/rotation} periods (*):
Equatorial............................25.4 days
Polar...................................36 days
Internal................................27 days
Adopted for @{"heliographic" link define.guide/heliographic} longitudes..25.38 days
Motion relative to nearby stars:
Direction (@{"right ascension" link define.guide/rightascension})............18 hours
Direction (@{"declination" link define.guide/declination})................30 degrees
Velocity............................19400 m/s
Distance from Earth:
Shortest......................147,098,447 km (0.9832923836 AU)
Average.......................149,598,023 km (1.0000010178 AU)
Greatest......................152,097,599 km (1.0167096520 AU)
Composition (by number of atoms):
Hydrogen............................92.1%
Helium...............................7.8%
Oxygen...............................0.061%
Carbon...............................0.030%
Nitrogen.............................0.0084%
Neon.................................0.0076%
Iron.................................0.0037%
Silicon..............................0.0031%
Magnesium............................0.0024%
Sulfur...............................0.0015%
Others...............................0.0015%
@remark endverbatim
* Since the Sun is basically a huge ball of gas, it does not rotate as a solid
body. As can be seen from the rotational periods, gas near the equator takes
less time to rotate around the Sun than gas at the poles. This
@{"differential rotation" link define.guide/differentialrotation} can also be observed with the @{"gas giant" link define.guide/gasgiantplanet} planets Jupiter,
Saturn, Uranus, and Neptune.
@endnode
@node object04100000structure "The Sun - Structure and Nuclear Processes"
Like most bodies in the solar system, the Sun is comprised of several layers,
each of which is different from the others in some fundamental respects.
@{"The Core" link define.guide/core}
========
Occupying the inner third of the Sun, the core reaches a temperature of
15,000,000 degrees C (27,000,000 degrees F), and a pressure 250,000,000,000
times more intense than that of the Earth's atmosphere at sea level. Since
nuclear @{"fusion" link define.guide/fusion} requires such extreme conditions, the core is the only place in
the Sun where it can occur.
Through the process of nuclear fusion, four hydrogen nuclei (four protons)
collide together and form an alpha particle, or helium nucleus (consisting of
two protons and two neutrons). However, the alpha particle is about 0.7%
lighter than the four protons. The missing mass is converted to energy in the
form of photons, as specified by Albert Einstein's famous equation: E=mc^2.
These photons then begin their long journey towards the surface of the Sun, and
eventually out into space.
In one second, the Sun converts 5 million metric tons of hydrogen into energy.
This output of a single second would be sufficient to satisfy the world's
current energy requirements for 1 million years.
@{"The Radiative Zone" link define.guide/radiativezone}
==================
The Radiative Zone occupies the region of the Sun encircling the core,
reaching out to within 150,000 km of the surface. When energetic photons from
within the core strike atomic nuclei in this layer, the photon is absorbed, and
another, slightly less energetic photon reemitted. In this way, the decreasing
photon energy causes the radiation to shift from gamma rays (as produced in the
core), to X-Rays, to extreme ultraviolet, to ultraviolet, to visible light.
Though an unimpeded photon, travelling at the speed of light, would only take
slightly over 2 seconds to emerge from the Sun, these frequent collisions in
random directions result in it taking 50 million years, on average, for energy
generated within the core to reach the surface.
As we move out from the center of the Sun through the radiative zone, we would
find the temperature, pressure, and density (as well as photon energy)
continually decreasing. Eventually, the temperature would be around 2,500,000
degrees C (4,500,000 degrees F) with a density about equal to that of water.
@{"The Convection Zone" link define.guide/convectionzone}
===================
Within the Core and Radiative Zone, the temperature is so high that atoms are
stripped of their electrons; they basically consist solely of their nuclei. By
the time that the Convection zone is reached, the temperature has cooled to the
point that the free electrons are starting to recombine with these nuclei,
becoming more opaque to radiation. This acts as a blanket and results in a
large temperature gradient going towards the surface.
Now, the energy is carried towards the surface by another process in addition
to radiation - convection. Heated fluids, because of their lower density, rise
while cooled fluids fall. A fluid heated from below will rise in a column
until it cools. At that point, it will move aside and fall to be re-heated,
continuing the process. Fluid trapped in this cycle is said to be part of a
"convection cell".
Convection can occur at any scale. Convection currents may be observed in a
warm pot of water (though if boiling, the convection becomes turbulent and more
difficult to observe). Towering thunderheads usually evolve their
characteristic appearance as warm, moist air rises through the center of the
cloud. As the air cools, the moisture condenses to form the cloud, while the
air moves aside and falls back down.
Convection cells on the Sun are much larger, however. The top of a column can
be 1000 km or more across. These convection cells may be observed in high
resolution white light images of the Sun. Since convection patterns appear as
`granules', the effect is often referred to as `granulation'.
@{"View picture of granulation" system "execute showpic sun/granulation.iff"}
@{"The Photosphere" link define.guide/photosphere}
===============
When we look at the Sun, we see the region known as the Photosphere. It is a
thin layer, perhaps only 100 km in depth, that produces the radiation
transmitted into space, since at its distance from the center of the Sun
photons are more likely to escape than be re-absorbed. The Photosphere is
considered to be the innermost layer of the Sun's atmosphere.
The conditions in the photosphere are much less severe than elsewhere in the
Sun. The temperature has dropped to a relatively cool 5500 degrees C, the
pressure is only one hundredth that of the Earth's atmosphere at sea level, and
the density is about one hundred millionth that of water.
The sun's @{"limb" link define.guide/limb} (edge) appears darker than at its center, due to an effect known
as @{"limb darkening" link define.guide/limbdarkening}. @{"Click here to see an example picture" system "execute showpic sun/sun_white.iff"}.
Since light travelling through the Photosphere is partially absorbed by
material located there, our line of sight can only see so far. When we look at
the center of the Sun's disk, we are looking through less of the Photosphere
than when we observe near the limb. As a result, we see deeper into the
Photosphere near the centre. The limb appears darker because our line of sight
ends higher in the atmosphere, where the temperature is cooler.
The Photosphere and other atmospheric layers are the home to a wide variety of
features which are visible on the Sun from the Earth. See @{"Solar Activity" link object04100000features} for
more information.
@{"The Chromosphere" link define.guide/chromosphere}
================
This is a level of the solar atmosphere immediately above the Photosphere,
extending about 2500 km out. At approximately 500 km above the Photosphere,
the temperature is only 3000-3500 degrees C. However for some reason not yet
fully understood, the temperature then rapidly increases to 1,000,000 degrees C
at its outer reaches. It is felt that the heating is due partially to a
dramatic density decrease (the density can be as low as 100 trillion times less
dense than water), as well as mechanical energy added to the Chromosphere from
the @{"Convection Zone" link define.guide/convectionzone}. @{"Granulation" link define.guide/granulation} can overshoot hundreds of kilometers into the
Chromosphere. Due to the decreased density, higher particle velocities are
possible, resulting in a higher temperature.
Also present in the Chromosphere are gas streams shooting up from the
Photosphere, known as @{"spicules" link define.guide/spicule}. These can be 800 kilometers thick, up to
15,000 kilometers high, and last for as long as 15 minutes.
@{"The Corona" link define.guide/corona}
==========
The outermost atmosphere of the Sun is known as the "Corona". Since it is
substantially less bright than the Photosphere, it can only be observed when
the surface of the Sun is blocked out during a total solar eclipse.
@{"View picture of Corona" system "execute showpic sun/sun_corona.iff"}
The Corona is dominated by intense magnetic fields, around which the gas
accumulates to create its beautiful and delicate structure. The temperature is
even higher than that in the Chromosphere, climbing to some 3,000,000 degrees
C. However, if an astronaut were to visit the corona and were somehow shielded
from the direct rays of the Sun, he or she wouldn't roast to death - in fact, a
spacesuit heating system would be required. This is because there simply isn't
a lot of gas in the corona. In fact, the atmospheric pressure within the corona
rivals laboratory work in creating an almost perfect vacuum.
There is enough energy in the corona to emit X-rays, however. An X-ray picture
of the Sun taken from space quite clearly shows the corona.
@{"View X-ray picture of Sun" system "execute showpic sun/sun_xray.iff"}
Coronal holes are the source of great streams of solar matter that flow outward
from the Sun. Termed the @{"solar wind" link object04100000wind}, these particles are continuously
bombarding the Earth causing a wide variety of geophysical phenomena (such as
aurorae or reduced radio reception).
@endnode
@node object04100000features "Solar Activity"
Under even casual inspection, the Sun appears as anything but a featureless
yellow disk. There are a variety of things to see - some of which can even be
observed with the @{"naked eye" link define.guide/nakedeye}. However, all solar observations must be done with
extreme caution. See @{"Observing the Sun safely" link object04100000observing} for further information.
@{"Sunspots" link define.guide/sunspot}
========
@{"View Picture 1 (close-up view of a sunspot group)" system "execute showpic sun/sunspots.iff"}
@{"View Picture 2 (full disk of Sun with sunspots) " system "execute showpic sun/sun_white.iff"}
First detected by @{"Galileo" link people.guide/galileo}, sunspots are perhaps the most well known solar
feature. Where strong magnetic fields intersect with the Photosphere, the
temperature of the surrounding gas can be lowered from 5500 degrees C to 4500
degrees C. Because of this, sunspots appear dark when viewed against the
background of the much brighter Sun.
A typical sunspot may have a diameter of more than 30,000 km (a few planets the
size of the Earth could easily fit within one). Most consist of two parts.
The inner region, called the @{"umbra" link define.guide/umbra}, is the darker of the two, and can reach
13,000 km in diameter. The outer region, known as the @{"penumbra" link define.guide/penumbra}, is somewhat
lighter in color. Some sunspots have no clearly defined penumbra because of
their smaller size.
The life of a sunspot can range from a few hours to several months. Those
sunspots which last longer can often be observed for several solar rotations,
and can be used to provide a rough verification of the @{"differential rotation" link define.guide/differentialrotation} of
the Sun with different latitudes.
@{"Granulation" link define.guide/granulation}
===========
@{"View Picture" system "execute showpic sun/granulation.iff"}
As mentioned in @{"The Sun - Structure and Nuclear Processes" link object04100000structure}, granulation may also
be observed on the Sun. Due to @{"convective" link define.guide/convection} currents in the @{"Convection Zone" link define.guide/convectionzone} of
the Sun, hot material from within is constantly being interchanged with cooler
material at the surface. The resulting appearance of the solar disk is
granulation.
@{"Spicules" link define.guide/spicule}
========
Spicules are structures present in the @{"Chromosphere" link define.guide/chromosphere} of the Sun. These streams
of gas shoot up from the @{"Photosphere" link define.guide/photosphere} and can be 800 kilometers thick, up to
15,000 kilometers high, and last for up to 15 minutes.
@{"Flares" link define.guide/flare}
======
Usually associated with @{"sunspots" link define.guide/sunspot}, flares are huge eruptions taking place on
the Sun. They are observed as an increase in brightness on the solar surface,
and often give rise to intense bursts of electromagnetic radiation.
The following plot contains a representation of such an event. The data was
recorded with the solar radio telescope at the Dominion Radio Astrophysical
Observatory in Penticton, BC, Canada on April 1, 1992. The flare can be seen to
begin at around 17:30 UT, reach a maximum of about 200 solar flux units above
the baseline, quickly decrease from its maximum, then take several hours to
return to its original, pre-flare level.
@{"View plot of solar flare radio emissions" system "execute showpic sun/cr920401.iff"}
Coronal Mass ejections
======================
Periodically, changes in the Sun's magnetic field trigger the ejection of
billions of tons of gas from the @{"corona" link define.guide/corona}. About 30% of the gas travels faster
than the @{"solar wind" link object04100000wind}, reaching velocities of up to 2000 km/sec. If this gas
reaches the Earth, a magnetic storm ensues.
These magnetic storms can affect the ionosphere of the Earth, resulting in a
disruption of telecommunications. Sometimes, compass needles are affected and
vast power outages occur. In the more northern or southern regions, the storms
often create spectacular aurorae. During periods of high solar activity, the
Earth intercepts about 70 coronal mass ejections per year.
Magnetic storms on the Earth were previously attributed to solar flares. This
mistaken relationship arose since flares are much brighter, and often occur at
the same time as coronal mass ejections. However, astronomer Jack Gosling, of
the Los Alamos National Laboratory presented evidence to the December, 1993
meeting of the American Geophysical Union indicating the relationship with
coronal mass ejections.
@{"Prominences & Filaments" link define.guide/prominence}
=======================
@{"View Picture 1 - Prominence on solar limb" system "execute showpic sun/prominence.iff"}
@{"View Picture 2 - Filaments on solar disk, seen in H-alpha light" system "execute showpic sun/halpha.iff"}
Gas suspended above the solar @{"Photosphere" link define.guide/photosphere} by the Sun's magnetic field is termed
a "prominence" if the gas is visible at the @{"limb" link define.guide/limb} of the Sun, and a "filament"
if the gas is seen against the solar disk as a background. Since filaments are
not as bright as the rest of the Sun, they appear as dark, snakelike features.
Viewing prominences or filaments requires a H-alpha filter with a bandwidth of 3
or 4 @{"angstroms" link define.guide/angstrom}. A filter passing a band of less than 1 angstrom is required to
see filaments on the solar disk.
@endnode
@node object04100000wind "The Solar Wind"
In addition to heat and light, the Sun also emits a continuous low density
stream of charged particles (mostly electrons and protons). Such a phenomenon
was long suspected by scientists, but first confirmed from data returned by the
@{"Mariner 2" link spacecraft.guide/mariner2} space probe. These particles are known as the "solar wind", and
travel away from the Sun at approximately 450 km/sec (1,620,000 km/hour) in
equatorial regions. Recent data from the @{"Ulysses" link spacecraft.guide/ulysses} spacecraft seems to indicate
that the solar wind originating from the south solar pole flows at nearly
double the rate (750 km/sec) while differing somewhat in composition.
The solar wind and higher energy particles released from the Sun during coronal
mass ejections combine to have strong effects on the Earth, ranging from
aurorae to power line surges to radio interference. Due to the relatively slow
speed of the solar wind (as compared to the speed of light at 299,792.458
km/sec), the effects are often felt a few days after an event is observed
visually or by radio telescopes.
The following plot contains a representation of such an event. The data was
recorded with the solar radio telescope at the Dominion Radio Astrophysical
Observatory in Penticton, BC, Canada on April 1, 1992. The flare can be seen to
begin at around 17:30 UT, reach a maximum of about 200 solar flux units above
the baseline, quickly decrease from its maximum, then take several hours to
return to its original, pre-flare level.
@{"View plot of solar flare radio emissions" system "execute showpic sun/cr920401.iff"}
The solar wind is believed to originate within "coronal holes" - regions of the
@{"corona" link define.guide/corona} less dense and cooler than surrounding areas. It has been observed by
the Voyager and Pioneer spacecraft to exist at least as far as the orbit of
Pluto.
@endnode
@node object04100000helioseismology "Helioseismology"
Since the Sun is basically just a ball of hot gas, its interior transmits sound
very well. In studying @{"doppler shifts" link define.guide/doppler} in the solar @{"spectrum" link define.guide/spectra}, the discovery of
propagating sound waves in the Sun was made as long ago as 1962. It was
noticed that certain parts of the Sun appeared to be receding while other parts
were approaching. Five minutes or so later, the roles would reverse. This led
scientists to the conclusion that the Sun was "pulsating" at a particular set
of frequencies.
It is generally believed that @{"convection" link define.guide/convection} near the surface of the Sun results in
vigorous turbulent flows that produce a broad spectrum of random acoustical
noise. Most of this noise is generated at approximately 0.003 Hz - far below
the human ear's limit of 20 Hz. Although sound is generated at a wide range of
frequencies, the shape of the Sun forms a spherical resonator. The net result
can be likened to a bell ringing at a particular frequency, even when hit by a
clapper at random intervals.
The precise frequencies at which the Sun resonates can be used to determine the
thermodynamic and compositional state of the material within, in much the same
way as geologists use seismic readings to deduce the nature of the Earth's
interior.
Evidence obtained between 1977 and 1989 seem to indicate that the primary
frequency of the Sun's resonation changes with the current point in the
@{"solar cycle" link object04100000cycle}. When the Sun is less active, the frequency is a bit less than
otherwise.
In the March 1995 issue of the "Astronomical Journal", astronomers reported
evidence of similar resonations in observations of @{"Eta Boötes" link duobjects.guide/object00001473}.
@endnode
@node object04100000cycle "The Solar Cycle"
The Sun's activity is not entirely constant. Between 1826 and 1843, the German
astronomer Heinrich Schwabe produced evidence to indicate that @{"sunspot" link define.guide/sunspot} activity
tended to follow an approximate 11 year cycle. From a minimal number of
sunspots, it took approximately four years to reach a peak of activity, then
about seven years to fall to a new minimum. Later it was discovered that after
every cycle of activity, the magnetic polarity of the sunspots was reversed.
This suggested the existence of a 22 year cycle. In addition, the data seems
to suggest an additional period of around 80 years.
In the last 100 years, the period of rise has ranged between 3.3 to 5.0 years,
and the period of fall between 5.7 to 8.3 years, so it is difficult to make
predictions about solar activity over any length of time.
At the beginning of each cycle (near minimum activity), sunspots occur in the
higher latitudes of the Sun (about 40 degrees from the equator), gradually
appearing nearer and nearer to the equator as the cycle progresses.
The number of visible sunspots is not the only indicator of solar activity that
seems to follow an 11 year cycle. Radio emissions at a wavelength of 10.7 cm
also confirm the pattern. There may also be some evidence that the weather on
the Earth may follow a similar cycle. From 1645 to 1717, hardly any sunspots
were recorded. This period was known as the "Maunder Minimum". Coinciding
with the decrease in sunspots, the average temperature on the Earth fell, and
particularly severe winters occurred in Europe.
In addition, studies published by Eigil Friis-Christensen and Knud Lassen of
the Danish Meteorological Institute in Copenhagen in the November 1, 1991 issue
of "Science" suggest another link between the solar cycle and climate
conditions on Earth. They presented data which indicates a surprisingly strong
relationship between the length of the solar cycle and the average temperature
of the Earth's atmosphere. Warmer temperatures seem to occur during shorter
solar cycles.
@endnode
@node object04100000observing "Observing the Sun safely"
It is likely that everyone has heard time and time again of the dangers of
looking directly at the Sun. But such a warning bears repetition: on countless
occasions, permanent blindness has been known to occur to individuals who do
not use proper methods of solar observation. There are several safe ways to
view the Sun which will be described here, but please ensure that you fully
understand the technique before you risk your eyesight.
Projection
==========
The safest way to study the Sun is to not look at it directly at all. You can
use a telescope or pair of binoculars to project an image of the Sun onto a
piece of cardboard. ENSURE THAT YOU NEVER LOOK THROUGH THE TELESCOPE OR
BINOCULARS AT THE SUN. EVEN A FRACTION OF A SECOND WILL PERMANENTLY BLIND YOU.
If you are using a pair of binoculars, cover one of the larger lenses first -
you will only need to use one side of the binoculars. Likewise, if you are
using a telescope with a finder scope, ensure that the finder is capped. Next,
aim the telescope or binoculars roughly at the Sun (again, ensure that you do
not look through the instrument to find the Sun). You will find it easy to
line the instrument up with the Sun by moving it around until its shadows are
as small as possible.
If you set up a piece of cardboard behind the telescope (on the same side of
the telescope as the eyepiece), and line the telescope up well, you will see
the image of the Sun projected onto the cardboard. You may have to adjust the
focusing knob to get a clear image. Experiment with moving the cardboard
nearer to or further from the eyepiece to get a smaller or larger image until
you have the result you want.
The projection method is more than adequate to allow you to view and chart the
movement of sunspots across the solar disk. One improvement you may wish to
make is to use another piece of cardboard to make a large "collar" around the
eyepiece of your instrument. If positioned properly, this collar will create a
shadow on the cardboard you are using as a projection screen, making your image
appear brighter and with higher contrast.
The projection method has the additional advantage that several people may
observe the Sun at the same time. Just ensure you understand that the Sun's
rays are being intensely concentrated by the lenses in the telescope or
binoculars to a point just a few millimeters behind the eyepiece. Do not put
anything near the eyepiece that you wish to keep (especially your eyes!). It
will burst into flame almost immediately.
Filters
=======
Another method of viewing the Sun is with the use of the appropriate filters.
Only use filters designed for this particular purpose - dark sunglasses and the
like will NOT work and will be dangerous. You should be able to find companies
advertising their solar filters for sale in reputable magazines such as "Sky &
Telescope" or "Astronomy".
There are two places where filters can be used in a telescope - at the
objective (or large lens), and at the eyepiece (the smaller lens). It is
strongly recommended that you never use a filter at the eyepiece (and in my
opinion, such filters should be banned). Eyepiece filters are dangerous in
that they are placed right where the light is being concentrated the most. As a
result, they can tend to heat up and crack without warning - blinding you
instantly if you happen to be looking through the eyepiece at the time. If you
really must use an eyepiece filter, ensure that you never keep the telescope
pointed at the Sun for more than a few minutes. As well, if you use a larger
telescope, construct a cardboard shield over the front of the instrument to
prevent most of the light from entering. This will hopefully keep the filter
cool enough to prevent cracking.
A much safer alternative is to use filters that fit over the objective of your
telescope. With such a filter, you can observe the Sun all day if you want to -
the filter doesn't warm up any more than the air around it. Of course, ensure
that the filter is securely attached to the telescope. You wouldn't want a
sudden gust of wind to pull it off, letting unfiltered light through the
telescope.
If you wish to observe @{"filaments" link define.guide/prominence} or @{"prominences" link define.guide/prominence}, you will need a special filter
called an H-alpha, or Hydrogen-alpha filter. This filter only allows one
particular wavelength of hydrogen to pass through, enabling you to see details
clearly.
@endnode
@node object04100000eclipse "Solar Eclipses"
NOTE: For any attempts at solar eclipse viewing, it is essential that you read
the section entitled @{"Observing the Sun safely" link object04100000observing}.
There are several different classifications of solar eclipses:
Total
=====
@{"View Picture" system "execute showpic sun/sun_corona.iff"}
The Sun is about 400 times larger than the Moon, and about 400 times further
away. As a result, it appears about the same size in the sky. However, the
Earth @{"revolves" link define.guide/revolution} around the Sun, and the Moon revolves around the Earth in
slightly elliptical orbits. The result is that the distances to these objects
changes slightly with time. Sometimes the Sun appears slightly larger than the
Moon, and sometimes the Moon appears slightly larger than the Sun. It is in
the latter case that a total eclipse is possible.
If the Moon passes directly between the Sun and your physical location on the
Earth, and appears slightly larger than the Sun, you will see a total solar
eclipse. For the few minutes of "totality", the Moon will appear to completely
cover the disk of the Sun.
In the hours before the moment of maximum eclipse, the Moon can be observed to
slowly obscure the Sun. A few minutes before totality, the total amount of
light from the @{"photosphere" link define.guide/photosphere} is reduced to the point that the blinking reflex
that normally protects our eyes from the Sun's light no longer works. This is
considered the most dangerous part of an eclipse, since people are tempted to
stare at the Sun, even though it is still perfectly capable of damaging their
eyesight.
Immediately before totality begins, brilliant points of light can be observed
on the edge of the Sun. Known as "Baily's beads", these are the last bits of
sunlight shining through valleys on the edge of the Moon. When the last
"Baily's bead" is visible before totality, the appearance is often called the
"diamond ring" effect. 3 to 5 seconds later, it too is obscured by the Moon.
For another few seconds, the pink @{"chromosphere" link define.guide/chromosphere} is visible, as well as any
@{"prominences" link define.guide/prominence} that may be there. Then totality begins.
During totality, you can see the @{"corona" link define.guide/corona} of the Sun. It always surrounds the
Sun, but since it shines a million times dimmer than the Sun itself, it is only
visible when the Sun is in a dark sky - in other words, only during a total
solar eclipse. During this phase of an eclipse (and ONLY during this phase),
you can look directly at the Sun, without filters, as the corona is only about
as bright as the full Moon.
During totality, the sky is as dark as it is during evening twilight. If you
look toward the horizon in any direction, you can see beyond the darkest part
of the moon's shadow. The result is a pinkish glow looking like a sunset
extending completely around the horizon.
Though the length of totality varies depending on your location and the
particular eclipse being observed, it will never last longer than about 7
minutes. Before it ends, you must stop looking directly at the Sun. The
sequence of events following totality mirror those which led up to the event.
Annular
=======
When the Moon moves directly between the Sun and your physical location on
Earth, but appears slightly smaller than the Sun, it will not be able to
completely cover the Sun and cause a total eclipse. At the moment of maximum
eclipse, an "annulus" or ring of the Sun around the Moon can be observed.
At no point during an annular eclipse is it safe to look at the Sun without
protective filters.
Partial
=======
When the Moon only appears to partially cover the Sun from your physical
location on Earth, the eclipse is said to be partial. Since the Moon appears
as almost the exact same size as the Sun, only a narrow band along the Earth
falls within its shadow and can observe a particular solar eclipse as being
total. Most of the remainder of the Earth must be content with viewing a
partial eclipse.
As with an annular eclipse, it is never safe to observe a partial eclipse of
the Sun without protective filters.
See also: @{"Eclipse Details: Solar Eclipse" link astro.guide/chapter4solareclipse}
@endnode
@node object04100000exploration "The Sun - Exploration"
The Sun has been the object of study for several interplanetary spacecraft. A
chronological list of some of these probes, sorted by launch date, follows:
@{"Pioneer 6 " link spacecraft.guide/pioneer6} - Dec. 16/65
@{"Pioneer 7 " link spacecraft.guide/pioneer7} - Aug. 17/66
@{"Pioneer 8 " link spacecraft.guide/pioneer8} - Dec. 13/67
@{"Pioneer 9 " link spacecraft.guide/pioneer9} - Nov. 8/68
@{"Pioneer E " link spacecraft.guide/pioneere} - Aug. 27/69
@{"Explorer 49" link spacecraft.guide/explorer49} - Jun. 10/73
@{"Helios 1 " link spacecraft.guide/helios1} - Dec. 10/74
@{"Helios 2 " link spacecraft.guide/helios2} - Jan. 15/76
@{"Ulysses " link spacecraft.guide/ulysses} - Oct. 6/90
@endnode
@node object04100000pictures "The Sun - Pictures"
Though links to these pictures occur in various places throughout the document,
they are provided here as well for convenience.
@{"White light image, showing limb darkening & sunspots" system "execute showpic sun/sun_white.iff"}
@{"Hydrogen-alpha image, showing filaments " system "execute showpic sun/halpha.iff"}
@{"X-ray image, showing activity in the corona " system "execute showpic sun/sun_xray.iff"}
@{"Image of the corona, during a total solar eclipse " system "execute showpic sun/sun_corona.iff"}
@{"Granulation on the surface of the Sun " system "execute showpic sun/granulation.iff"}
@{"Close up view of sunspots " system "execute showpic sun/sunspots.iff"}
@{"Image of a prominence taken in Hydrogen-alpha light " system "execute showpic sun/prominence.iff"}
@{"View plot of solar flare radio emissions " system "execute showpic sun/cr920401.iff"}
@endnode
@node object04200000ff "Mercury - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000myth "Mercury - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000discovery "Mercury - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000exploration "Mercury - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000orbit "Mercury - A Strange Orbit"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000day "Mercury - The length of its day"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000features "Mercury - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000observing "Mercury - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04200000pictures "Mercury - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000ff "Venus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000myth "Venus - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000discovery "Venus - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000exploration "Venus - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000greenhouse "Venus - A Runaway Greenhouse Effect"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000day "Venus - Length of the Day"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000features "Venus - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000observing "Venus - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04300000pictures "Venus - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04400000ff "Earth - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04400000structure "Earth - Structure"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04400000atmosphere "Earth - Atmosphere"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04400000pictures "Earth - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000ff "The Moon - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000exploration "The Moon - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000features "The Moon - Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000day "The Lunar day"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000phases "Phases of the Moon"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04401000pictures "The Moon - Pictures & Audio clips"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000ff "Mars - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000myth "Mars - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000discovery "Mars - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000exploration "Mars - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000features "Mars - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000life "Is there life on Mars?"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000observing "Mars - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04500000pictures "Mars - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04501000ff "Phobos - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04501000description "Phobos - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04502000ff "Deimos - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04502000description "Deimos - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000ff "Jupiter - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000myth "Jupiter - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000discovery "Jupiter - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000exploration "Jupiter - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000features "Jupiter - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000ring "Jupiter's ring"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000observing "Jupiter - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000sl9 "Jupiter - Collision with Comet Shoemaker-Levy 9"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04600000pictures "Jupiter - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04603000ff "Ganymede - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04603000description "Ganymede - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04604000ff "Callisto - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04604000description "Callisto - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04601000ff "Io - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04601000description "Io - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04602000ff "Europa - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04602000description "Europa - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04605000ff "Amalthea - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04605000description "Amalthea - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460A000ff "Himalia - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460A000description "Himalia - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04606000ff "Thebe - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04606000description "Thebe - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460C000ff "Elara - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460C000description "Elara - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460F000ff "Pasiphae - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460F000description "Pasiphae - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04607000ff "Metis - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04607000description "Metis - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460E000ff "Carme - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460E000description "Carme - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460B000ff "Lysithea - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460B000description "Lysithea - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04610000ff "Sinope - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04610000description "Sinope - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460D000ff "Ananke - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0460D000description "Ananke - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04608000ff "Adrastea - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04608000description "Adrastea - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04609000ff "Leda - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04609000description "Leda - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000ff "Saturn - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000myth "Saturn - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000discovery "Saturn - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000exploration "Saturn - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000features "Saturn - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000ring "Saturn's rings"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000observing "Saturn - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04700000pictures "Saturn - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04706000ff "Titan - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04706000description "Titan - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04701000ff "Mimas - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04701000description "Mimas - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04702000ff "Enceladus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04702000description "Enceladus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04703000ff "Tethys - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04703000description "Tethys - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04704000ff "Dione - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04704000description "Dione - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04705000ff "Rhea - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04705000description "Rhea - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04707000ff "Hyperion - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04707000description "Hyperion - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04708000ff "Iapetus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04708000description "Iapetus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04709000ff "Phoebe - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04709000description "Phoebe - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470A000ff "Telesto - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470A000description "Telesto - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470B000ff "Calypso - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470B000description "Calypso - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470C000ff "Helene - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470C000description "Helene - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470D000ff "Pan - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470D000description "Pan - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470E000ff "Atlas - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470E000description "Atlas - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470F000ff "Prometheus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0470F000description "Prometheus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04710000ff "Pandora - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04710000description "Pandora - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04711000ff "Epimetheus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04711000description "Epimetheus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04712000ff "Janus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04712000description "Janus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000ff "Uranus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000myth "Uranus - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000discovery "Uranus - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000exploration "Uranus - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000features "Uranus - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000ring "Uranus' rings"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000observing "Uranus - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04800000pictures "Uranus - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04801000ff "Miranda - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04801000description "Miranda - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04802000ff "Ariel - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04802000description "Ariel - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04803000ff "Umbriel - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04803000description "Umbriel - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04804000ff "Titania - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04804000description "Titania - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04805000ff "Oberon - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04805000description "Oberon - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04806000ff "Cordelia - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04806000description "Cordelia - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04807000ff "Ophelia - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04807000description "Ophelia - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04808000ff "Bianca - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04808000description "Bianca - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04809000ff "Cressida - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04809000description "Cressida - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480A000ff "Desdemona - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480A000description "Desdemona - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480B000ff "Juliet - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480B000description "Juliet - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480C000ff "Portia - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480C000description "Portia - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480D000ff "Rosalind - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480D000description "Rosalind - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480E000ff "Belinda - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480E000description "Belinda - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480F000ff "Puck - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object0480F000description "Puck - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000ff "Neptune - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000myth "Neptune - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000discovery "Neptune - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000exploration "Neptune - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000features "Neptune - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000ring "Neptune's rings"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000furthest "What is the furthest planet from the Sun?"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000observing "Neptune - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04900000pictures "Neptune - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04901000ff "Triton - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04901000description "Triton - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04902000ff "Nereid - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04902000description "Nereid - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04903000ff "Naiad - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04903000description "Naiad - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04904000ff "Thalassa - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04904000description "Thalassa - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04905000ff "Despina - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04905000description "Despina - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04906000ff "Galatea - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04906000description "Galatea - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04907000ff "Larissa - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04907000description "Larissa - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04908000ff "Proteus - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04908000description "Proteus - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000ff "Pluto - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000myth "Pluto - Mythology"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000discovery "Pluto - Discovery"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000exploration "Pluto - Exploration"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000features "Pluto - Physical Features"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000orbit "Pluto - its strange orbit"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000observing "Pluto - Observing the Planet"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A00000pictures "Pluto - Pictures"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A01000ff "Charon - Fast Facts"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode
@node object04A01000description "Charon - Description"
This information is not provided with the demonstration version of
"The Digital Universe". Please consult @{"Ordering The Digital Universe" link duhelp.guide/ordering}
for more information on how to obtain a registered version.
@endnode