THE COSMIC EXPLORER
(600-2409) Features Faxback Doc. # 33040
Please read before using this equipment.
INTRODUCTION: Radio Shack welcomes you to a wonderful opportunity to
explore the visible universe surrounding earth by using its
Cosmic Explorer. As you see in the illustration Panel 1, our
observable sky is only a very tiny part of our Home Galaxy,
which is a very small part of the universe. Yet, there are a
great many unsolved questions just in our starry backyard.
Questions like - how many stars are there? How do stars and
planets form? We hope that by using your Cosmic Explorer as
a tool for expanding your knowledge and wisdom you will
become a more aware cosmic observer.
THE COSMIC EXPLORER FEATURES
EXPLANATION OF FEATURES:
The Cosmic Explorer is a 3-D STAR MAP that can be quickly set up for
observing the ski on any day of the year, from anywhere on earth. For
expediency, we will describe how to set up the Cosmic Explorer for an
observer at about 40 degrees latitude. We select this latitude because
the vast majority of Earth observers live between 10 degrees and 50
degrees NORTH latitude.
Position your Cosmic Explorer so it looks like the view photo in figure 2.
Don't be afraid to pick up the Star Ball for examination. The more you
handle it, the easier it is to understand.
IMPORTANT: Always keep the Star Seeker support rod pointed North-South
while the equator is resting on the yellow support pad. For 40
degrees latitude observation, turn the Star Seeker control knob
so the pivoting and gimbaled figure has its head up, toward the
Zenith, which is the overhead point on the star ball. Now,
let's discuss the components of the Cosmic Explorer.
FEATURES FROM FIGURE 1
Star Ball:
This transparent l5" sphere is carefully crafted with over 200 manufac-
turing steps to create a realistic 3-D star map. All 88 recognized
constellations, their names and outlines are shown. We made the surface
direct reading. This means that what you see on the Star Ball for a
particular date will be seen in the sky on that same night. The Star Ball
is imprinted with the Equator and the Ecliptic. Note that the Star Ball
consists of two hemispheres, NORTH and South.
Equator:
This is a great circle that divides the Star Ball into a northern starry
hemisphere and a southern starry hemisphere. Notice that there are
numbers printed on the Equator. Pick up the ball and trace the numbers
with your Finger. You can see that the numbers start with 0^h and
increase to the right, or Eastward. There are 24 of these increments
(0-23). They are the hour circles of Right Ascension. Every object in
the sky has two coordinates. One is the Right Ascension. It is similar
to Longitude in Earth's geography. Each hour of Right Ascension is made
up of 60 minutes (m) and Each minute is made up of 60 seconds(s). We will
use Right Ascension for stars and planets. Imagine that there are 24 arcs
on your star ball which cross the Equator at right angles. Each arc
terminates in the NORTH and South poles of the star ball. The Equator is
0 degrees Declination, which increases to +90 Degrees at the North Pole
and -90 Degrees at the South Pole. More on this in a later section.
Sky Calendar (Ecliptic):
This is another very important great circle on the Star Ball. Pick up the
Star Ball and trace the Ecliptic around the sky. If you imagine a disk
floating in the Star Ball with its edge aligned with the Ecliptic, then
you can visualize the plane or disk our planetary system makes. The dates
on the Ecliptic represent where the sun is found each day of year. We
used 5^d increments so you will have to estimate the particular day you
select if it falls between the 5^d increments.
While Each day is important, there are four parts of the Ecliptic that are
exceptional for use. These are:
- September 21: Notice that this places the sun on the Equator at the
12^h mark. This is the Autumn Equinox for inhabitants of
the Northern hemisphere. The sun crosses the Equator and
moves South. It is in the constellation Virgo.
- December 21: Note that the sun's position is as far South as it will
go. It is in the constellation Scorpius. We call this
the Winter Solstice and it marks the end of autumn and
beginning of winter. Southern hemisphere observers see
this as their Summer Solstice, marking the end of spring.
- March 20: The sun crosses the Equator at 0^h Right Ascension. It
has moved from Aquarius into Pisces. We call this the
spring or Vernal Equinox. Keep tracing the sun's path
along the Ecliptic and you will see that it reaches the
its highest point where Taurus and Gemini meet.
- June 20: This is the Summer Solstice. It marks the end of spring
and the start of summer. The Ecliptic, and the sun, are
23.5 degrees NORTH of the Equator. During the Winter
Solstice, it is 23.5 degrees South of the equator. You
can check this with your Degree Scale. Lay the 0 degrees
line on the equator and the 90 degrees on the North Star.
Notice that the Summer solstice is at the 23.5 degrees
region of the degree scale which is marked off in
5 degrees increments.
Horizon Ring: This disk encircles the star globe, dividing it into the
sky which is up and visible at any given time and that
which is below the Horizon. Notice that the Star Seeker
is always above the Horizon Ring, viewing the visible
sky. If the Star Ball a bit so it is free of the three
support pads. Rotate the ball westward, keeping the
Equator oriented to the position indicators (EQUATOR
HERE) at the W and E cardinal joints. As you do this,
the stars will rise in the East and set in West. Believe
it or not, the rising and setting of the stars-where they
went to after crossing the western Horizon-was a great
mystery to humans for thousands of years. A good part of
ancient Egyptian religion rested on their fanciful
theories of fast underworld with gods that controlled the
heavens. More on the Horizon Ring in the other sections.
Star Seeker: This gimbaled figure represents You, the observer
placed on each. If you set up the Star Ball so that the
North Star is straight up and the Equator is aligned with
the Horizon Ring, then you have the sky set for an
observer standing at Earth's North pole. Try it now!
Rotate the star ball East to West. Notice that the stars
below the horizon never rise for this observer. Also,
for this observer, the sun is above the horizon for six
months of darkness!
Now, turn the ball so that the South pole, marked by the
Star Seeker position knob, is straight up. This is how
the sky looks for an observer at the South pole! Just the
opposite of our North pole observer.
Do you think there is a place where all the stars can be
seen in the course of a year? If you said-0 degrees on
Earth, which is the Earth's equator, you are correct.
Set up the Star Ball so that the position knob for the
Star Seeker rests against the underside of the Horizon
Ring at the S point. The North star should be pointing
at the N point on the Horizon Ring. This is how the sky
looks for an Earth observer who lives in places like
Ecuador, Gabon, Kenya, or Singapore and points in
between. Rotate the Star Ball to the West and you can
see that all of the stars are visible at one time of year
or another.
VIEW FROM EAST
Now, what about the observer at 40 degrees North latitude. What will they
see? Read on to find out how to set up the Star Ball. You should be able
to figure this out yourself using the 3-D power of the Cosmic Explorer.
Degree Scale and Yellow Support Pad:
We made this yellow bumper so it is about 10 degrees from top to bottom as
measured on your degree scale. If you position the Equator of the Star
Ball on the bottom edge of the yellow pad, then the Ball will be set for
an Earth observer at 40 degrees North Latitude.
You can check the proper orientation of the ball another way for observers
living at different latitudes by using the Degree Scale.
If you position the Degree Scale as shown and rotate the Star Ball until
the 40 degrees mark is straight up, then you have set up the ball for an
observer at 40 degrees North Latitude. (Notice that the Equator is on the
bottom of the Yellow Pad). Try this method for observers living at the
latitudes shown in TABLE 1.
(BR/EB 5/10/96)
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