8
JUPITER:
The largest planet, Jupiter, is a great subject for
observation. You can see the disk of the giant planet and
watch the ever-changing positions of its four largest moons—
Io, Callisto, Europa, and Ganymede.
SATURN:
The ringed planet is a breathtaking sight when it is
well positioned. The tilt angle of the rings varies over a period
of many years; sometimes they are seen edge-on, while at
other times they are broadside and look like giant “ears” on
each side of Saturn’s disk. A steady atmosphere (good see-
ing) is necessary for a good view. You will probably see a
bright “star” close by, which is Saturn’s brightest moon, Titan.
VENUS:
At its brightest, Venus is the most luminous object in
the sky, excluding the Sun and the Moon. It is so bright that
sometimes it is visible to the naked eye during full daylight!
Ironically, Venus appears as a thin crescent, not a full disk,
when at its peak brightness. Because it is so close to the Sun,
it never wanders too far from the morning or evening horizon.
No surface markings can be seen on Venus, which is always
shrouded in dense clouds.
MARS:
The Red Planet makes its closest approach to Earth
every two years. During close approaches you’ll see a red
disk, and may be able to see the polar ice cap.
C. The Stars
Stars will appear like twinkling points of light. Even powerful
telescopes cannot magnify stars to appear as more than a
point of light. You can, however, enjoy the different colors of the
stars and locate many pretty double and multiple stars. The
famous “Double-Double” in the constellation Lyra and the gor-
geous two-color double star Albireo in Cygnus are favorites.
Defocusing a star slightly can help bring out its color.
D. Deep-Sky Objects
Under dark skies, you can observe a wealth of fascinating
deep-sky objects, including gaseous nebulas, open and globu-
lar star clusters, and a variety of different types of galaxies.
Most deep-sky objects are very faint, so it is important that you
find an observing site well away from light pollution. Take plenty
of time to let your eyes adjust to the darkness. Do not expect
these subjects to appear like the photographs you see in books
and magazines; most will look like dim gray smudges. Our eyes
are not sensitive enough to see color in deep-sky objects
except in a few of the brightest ones. But as you become more
experienced and your observing skills get sharper, you will be
able to ferret out more and more subtle details and structure.
To find deep sky objects in the sky, it is best to consult a star
chart or Planisphere. These guides will help you locate the
brightest and best deep-sky objects for viewing with your
SpaceProbe 3 Altaz.
6. care and Maintenance
If you give your telescope reasonable care, it will last a life-
time. Store it in a clean, dry, dust free place, safe from rapid
changes in temperature and humidity. Do not store the tele-
scope outdoors, although storage in a garage or shed is OK.
Small components like eyepieces and other accessories
should be kept in a protective box or storage case. Keep the
caps on the front of the telescope and on the focuser draw-
tube when not in use.
Your SpaceProbe 3 Altaz telescope requires very little
mechanical maintenance. The optical tube is steel and has a
smooth painted finish that is fairly scratch resistant. If a scratch
does appear, it will not harm the telescope. Refer to Appendix
B at the end of this manual for details of how to clean your
telescope’s optics.
7. specifications
Optical tube: Steel
Primary mirror diameter: 76mm
Primary mirror coating: Aluminum with silicon dioxide (SiO
2
)
overcoat
Secondary mirror minor axis: 19.9mm
Focal length: 700mm
Focal ratio: f/9.2
Focuser: Rack and pinion, accepts 1.25" eyepieces
Eyepieces: 25mm and 10mm Explorer II eyepieces, 1.25"
Finder: EZ Finder II reflex sight
Magnification: 28x (with 25mm) and 70x (with 10mm)
Tripod: Aluminum
Weight: 8.4 lbs.
appendix a: collimating—
aligning the Mirrors
Collimating is the process of adjusting the mirrors so they are
perfectly aligned with one another. Your telescope’s optics
were aligned at the factory, and should not need much adjust-
ment unless the telescope is handled roughly. Accurate mirror
alignment is important to ensure the peak performance of
your telescope, so it should be checked regularly. Collimating
is relatively easy to do and can be done in daylight.
To check collimation, remove the eyepiece and look down the
focuser drawtube. You should see the secondary mirror cen-
tered in the drawtube, as well as the reflection of the primary
mirror centered in the secondary mirror, and the reflection of
the secondary mirror (and your eye) centered in the reflection
of the primary mirror, as in Figure 6a. If anything is off-center,
proceed with the following collimation procedure.
the collimation cap and Mirror center Mark
Your SpaceProbe 3 comes with a collimation cap. This is a
simple cap that fits on the focuser drawtube like a dust cap,
but has a hole in the center and a silver bottom. This helps
