Orion SpaceProbe 3 EQ User manual

INSTRUCTION MANUAL
IN 208 Rev. C 02/09
Providing Exceptional Consumer Optical Products Since 1975
Customer Support (800)-676-1343
E-mail: [email protected]
Corporate Offices (831)-763-7000
89 Hangar Way, Watsonville, CA 95076
Orion®
SpaceProbe™3 EQ
#9843 Equatorial Reflector Telescope

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Figure 1. The SpaceProbe 3 EQ.
EZ Finder II
EZ Finder II bracket
Declination slow-motion
control cable
Declination lock knob
Declination setting circle
Counterweight shaft
Counterweight
Counterweight lock knob
Right Ascension lock knob
(not shown)
Leg lock knob
Eyepiece
Focuser
Optical tube assembly
Right Ascension
setting-circle
Right Ascension slow-
motion control cable
Latitude adjustment T-bolt
Tripod leg
Accessory tray bracket
Accessory tray

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Table of Contents
1. Unpacking........................ 3
2. Parts List......................... 3
3. Assembly ........................ 3
4. Getting Started .................... 4
5. Setting up and Using the
Equatorial Mount................... 6
6. Using your Telescope ............... 8
7. Care and Maintenance ............. 10
8. Specifications .................... 11
Appendix A: Collimation
(Aligning the Mirrors) .............. 12
Appendix B: Cleaning the Optics ..... 14
1. Unpacking
The entire telescope system will arrive in one box. Be careful
unpacking the box. We recommend keeping all original pack-
aging. In the event that the telescope needs to be shipped to
another location, or returned to Orion for warranty repair, hav-
ing the proper packaging will help ensure that your telescope
will survive the journey intact.
Make sure all the parts in the Part List are present. Be sure
to check the box carefully, as some parts are small. If any-
thing appears to be missing or broken, immediately call Orion
Customer Support (800-676-1343) for assistance.
2. Parts List
Qty. Description
1 Optical tube assembly
1 Equatorial mount
3 Tripod legs with accessory tray bracket attached
2 Slow-motion control cables
1 Counterweight
1 Counterweight shaft
1 EZ Finder II with bracket
1 Accessory tray with attachment wing screws
3 Tripod attachment screws with wing nuts and
washers
3 Leg lock knobs
1 25mm Explorer II eyepiece
1 10mm Explorer II eyepiece
1 Dust cover
1 Collimation cap
3. Assembly
Assembling the telescope for the first time should take
about 30 minutes. You will need a Phillips head screwdriver
to assemble the telescope. All screws should be tightened
securely to eliminate flexing and wobbling, but be careful not
to over-tighten or the threads may strip. Refer to Figure 1 dur-
ing the assembly process.
During assembly (and anytime, for that matter), DO NOT touch
the surfaces of the telescope mirrors or the lenses of the find-
er scope or eyepiece with your fingers. The optical surfaces
have delicate coatings on them that can easily be damaged
if touched inappropriately. NEVER remove any lens assembly
from its housing for any reason, or the product warranty and
return policy will be voided.
1. Lay the equatorial mount on its side. Attach the tripod legs,
one at a time, to the base of the mount by sliding a tripod
leg attachment screw through the top of a leg and through
the holes in the base of the mount. The washers should
Welcome to the exciting world of amateur astronomy! Your SpaceProbe 3 EQ is a high-quality optical
instrument designed for nighttime stargazing. With its precision optics and equatorial mount, you’ll be
able to locate and enjoy fascinating denizens of the night sky, including the planets, Moon, and a variety
of deep-sky objects. Lightweight and easy to use, this scope will provide many hours of enjoyment for the
whole family.
These instructions will help you set up, properly use, and care for your telescope. Please read them over
thoroughly before getting started.
Warning: Never look at the sun with your
telescope or its finderscope—even for an
instant—without a professionally made solar
filter that completely covers the front of the
instrument, or permanent eye damage could
result. Young children should use this telescope
only with adult supervision.
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be on the outside of the tripod legs. Secure the wing nuts
finger-tight.
2. Install and tighten the leg lock knobs on the bottom braces
of the tripod legs. For now, keep the legs at their short-
est (fully retracted) length; you can extend them to a more
desirable length later, after the tripod is completely assem-
bled.
3. Stand the tripod and mount upright and spread the tripod
legs apart as far as they will go, until the bracket is taut.
Connect the accessory tray to the accessory tray bracket
with the three wing screws already installed in the tray. Do
this by pushing the wing screws up through the holes in
the accessory tray bracket and threading them into the
holes in the accessory tray.
4. Next, tighten the screws at the tops of the tripod legs,
so the legs are securely fastened to the mount. Use the
Phillips head screwdriver and your fingers to do this.
5. Orient the equatorial mount as it appears in Figure 2, at a
latitude of about 40°, i.e., so the pointer next to the latitude
scale is pointing to the hash mark at “40.” To do this, loosen
the latitude lock t-bolt, and turn the latitude adjustment t-
bolt until the pointer and the “40” line up. Then retighten the
latitude lock t-bolt. The declination (Dec.) and right ascen-
sion (R.A.) axes may need re-positioning (rotation) as well.
Be sure to loosen the R.A. and Dec. lock knobs before
doing this. Retighten the R.A. and Dec. lock knobs once
the equatorial mount is properly oriented.
6. Thread the counterweight shaft into the equatorial mount
at the base of the declination axis until tight.
7. Remove the screw and washer on the bottom of the coun-
terweight shaft and slide the counterweight onto the shaft.
Make sure the counterweight lock knob is adequately loos-
ened to allow the counterweight shaft to pass through the
hole. Position the counterweight about halfway up the shaft
and tighten the lock knob. Replace the screw and washer
on the end of the shaft.
8. Remove the two wingnuts from the optical tube assembly.
Place the optical tube assembly on top of the equatorial
mount and secure it with the wing nuts. Refer to Figure 1
for orientation of the tube.
9. Attach the two slow-motion cables to the R.A. and Dec.
worm gear shafts of the equatorial mount by positioning
the thumbscrew on the end of the cable over the indented
slot on the worm gear shaft and then tightening the thumb-
screw. We recommend that the shorter cable be used on
the R.A. worm gear shaft and the longer cable on the Dec.
worm gear shaft.
10. Remove the two metal thumbnuts located near the focuser
at the front of the optical tube. Place the bracket of the EZ
Finder II on the tube so that the holes in the bracket slide
over the two threaded posts on the tube. The EZ Finder
should be oriented so that it appears as in Figure 1. Thread
the thumbnuts back onto the posts to secure the EZ Finder
II in place.
11. Insert the 25mm Explorer II eyepiece into the focuser
drawtube and secure it in place with the thumbscrew.
Your telescope is now fully assembled and should appear as
it does in Figure 1.
4. Getting Started
Balancing the Telescope
To insure smooth movement of the telescope, it should be prop-
erly balanced. This is done by positioning the counterweight on
its shaft at a point where it is balanced on the R.A. axis.
1. Keeping one hand on the optical tube, loosen the R.A. lock
knob. Make sure the declination lock knob is locked. The
telescope should now be able to rotate freely about the
Figure 2. The equatorial mount of the SpaceProbe 3 EQ.
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Declination lock knob
(not shown)
Declination setting circle
R.A. lock knob
Latitude lock T-bolt
R.A. setting circle
Latitude scale
Latitude adjustment T-bolt
Azimuth lock knob

R.A. axis. Rotate it until the counterweight shaft is parallel
to the ground (i.e., horizontal)
2. Now loosen the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances the
telescope (Figure 3a). That’s the point at which the shaft
remains horizontal even when you let go of the telescope
with both hands (Figure 3b).
3. Retighten the counterweight lock knob. The telescope is
now balanced in the right ascension axis. The telescope is
already balanced in the declination axis.
Now when you loosen the lock knob on one or both axes and
manually point the telescope, it should move without resis-
tance and should not drift from where you point it.
Focusing the Telescope
Insert the 25mm Explorer II eyepiece into the focuser and
secure with the thumbscrew. Move the telescope so the front
(open) end is pointing in the general direction of an object at
least 1/4-mile away. Now with your fingers, slowly rotate one
of the focusing knobs until the object comes into sharp focus.
Go a little bit beyond sharp focus until the image starts to blur
again, then reverse the rotation of the knob, just to make sure
you’ve hit the exact focus point.
Do You Wear Eyeglasses?
If you wear eyeglasses, you may be able to keep them on
while you observe. In order to do this, your eyepiece must
have enough “eye relief” to allow you to see the entire field of
view with glasses on. You can try this by looking through the
eyepiece first with your glasses on and then with them off, and
see if the glasses restrict the view to only a portion of the full
field. If the glasses do restrict the field of view, you may be
able to observe with your glasses off by just refocusing the
telescope the needed amount.
If your eyes are astigmatic, images will probably appear the
best with glasses on.This is because a telescope’s focuser can
accommodate for nearsightedness or farsightedness, but not
astigmatism. If you have to wear your glasses while observing
and cannot see the entire field of view, you may want to pur-
chase additional eyepieces that have longer eye relief.
Operating the EZ Finder II reflex finder
The EZ Finder II reflex finder (Figure 4) works by projecting a
tiny red dot onto a lens mounted in the front of the unit. When
you look through the EZ Finder II, the red dot will appear to float
in space, helping you locate even the faintest of deep space
objects.The red dot is produced by a light-emitting diode (LED),
not a laser beam, near the rear of the sight. A replaceable 3-volt
lithium battery provides the power for the diode.
To use the EZ Finder II, turn the power knob clockwise until
you hear a “click” indicating that power has been turned on.
With your eyes positioned at a comfortable distance, look
through the back of the reflex sight with both eyes open to
see the red dot. The intensity of the dot can be adjusted by
Figure 3. Proper operation of the equatorial mount requires
balancing the telescope tube on the R.A. axis (a). With the R.A. lock
knob released, slide the counterweight along the counterweight
shaft until it just counterbalances the tube (b). When you let go with
both hands, the tube should not drift up or down.
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a.
b.
Figure 4. The EZ Finder II.
Azimuth knob
Power knob
Altitude
knob
Metal
thumbnuts
Battery
casing

turning the power knob. For best results when stargazing, use
the dimmest possible setting that allows you to see the dot
without difficulty. Typically, a dim setting is used under dark
skies and a bright setting is used under light-polluted skies or
in daylight.
At the end of your observing session, be sure to turn the
power knob counterclockwise until it clicks off. When the two
white dots on the EZ Finder II’s rail and power knob are lined
up, the EZ Finder II is turned off.
Aligning the EZ Finder II
When the EZ Finder II is properly aligned with the telescope,
an object that is centered on the EZ Finder II’s red dot should
also appear in the center of the field of view of the telescope’s
eyepiece. Alignment of the EZ Finder II is easiest during day-
light, before observing at night. Aim the telescope at a dis-
tant object at least 1/4 mile away, such as a telephone pole or
chimney and center it in the telescope’s eyepiece. Now, turn
the EZ Finder II on and look through it. The object will appear
in the field of view near the red dot.
Note: The image in the eyepiece of the telescope will be
upside-down (rotated 180°). This is normal for Newtonian
reflector telescopes.
Without moving the telescope, use the EZ Finder II’s azimuth
(left/right) and altitude (up/down) adjustment knobs to position
the red dot on the object in the eyepiece.
When the red dot is centered on the distant object, check to
make sure that the object is still centered in the telescope’s
field of view. If not, recenter it and adjust the EZ Finder II’s
alignment again. When the object is centered in the eyepiece
and on the red dot, the EZ Finder II is properly aligned with
the telescope.
Once aligned, EZ Finder II will usually hold its alignment even
after being removed from its bracket. If the EZ Finder II’s
bracket is removed entirely from the optical tube then realign-
ment will be needed.
5. Setting up and Using the
Equatorial Mount
When you look at the night sky, you no doubt have noticed that
the stars appear to move slowly from east to west over time.
That apparent motion is caused by the Earth’s rotation (from
west to east). An equatorial mount (Figure 2) is designed to
compensate for that motion, allowing you to easily “track” the
movement of astronomical objects, thereby keeping them
from drifting out of the telescope’s field of view while you’re
observing.
This is accomplished by slowly rotating the telescope on its
right ascension (R.A.) axis, using only the R.A. slow-motion
cable. But first the R.A. axis of the mount must be aligned
with the Earth’s rotational (polar) axis—a process called polar
alignment.
Polar Alignment
For Northern Hemisphere observers, approximate polar align-
ment is achieved by pointing the mount’s R.A. axis at the
North Star, or Polaris. It lies within 1° of the north celestial pole
(NCP), which is an extension of the Earth’s rotational axis
out into space. Stars in the Northern Hemisphere appear to
revolve around the NCP.
To find Polaris in the sky, look north and locate the pattern
of the Big Dipper (Figure 5). The two stars at the end of the
“bowl” of the Big Dipper point right to Polaris.
Observers in the Southern Hemisphere aren’t so fortunate to
have a bright star so near the south celestial pole (SCP). The
star Sigma Octantis lies about 1° from the SCP, but it is barely
visible with the naked eye (magnitude 5.5).
To polar-align the SpaceProbe 3 EQ:
1. Level the equatorial mount by adjusting the length of the
three tripod legs.
2. Loosen the latitude lock t-bolt. Turn the latitude adjustment
t-bolt and tilt the mount until the pointer on the latitude
scale is set at the latitude of your observing site. If you don’t
know your latitude, consult a geographical atlas to find it.
For example, if your latitude is 35° North, set the pointer to
35. Then retighten the latitude lock t-bolt. The latitude set-
ting should not have to be adjusted again unless you move
to a different viewing location some distance away.
3. Loosen the Dec. lock knob and rotate the telescope optical
tube until it is parallel with the R.A. axis, as it is in Figure
1. The pointer on the Dec. setting circle should read 90°.
Retighten the Dec. lock lever.
4. Loosen the azimuth lock knob at the base of the equa-
torial mount and rotate the mount so the telescope tube
(and R.A. axis) points roughly at Polaris. If you cannot see
Polaris directly from your observing site, consult a com-
pass and rotate the mount so the telescope points North.
Retighten the azimuth lock knob.
The equatorial mount is now polar aligned.
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Figure 5. To find Polaris in the night sky, look north and find the
Big Dipper. Extend an imaginary line from the two “Pointer Stars”
in the bowl of the Big Dipper. Go about five times the distance
between those stars and you'll reach Polaris, which lies within 1°
of-the north celestial pole (NCP).
Big Dipper
(in Ursa
Major)
Little Dipper
(in Ursa Minor)
N.C.P.
Pointer Stars
Polaris
Cassiopeia

From this point on in your observing session, you should not
make any further adjustments in the azimuth or the latitude
of the mount, nor should you move the tripod. Doing so will
undo the polar alignment. The telescope should be moved
only about its R.A. and Dec. axes.
Use of the R.A. and Dec.
Slow-Motion Control Cables
The R.A. and Dec. slow-motion control cables allow fine adjust-
ment of the telescope’s position to center objects within the
field of view. Before you can use the cables, you must manu-
ally “slew” the mount to point the telescope in the vicinity of
the desired target. Do this by loosening the R.A. and Dec. lock
knobs and moving the telescope about the mount’s R.A. and
Dec. axes. Once the telescope is pointed somewhere close to
the object to be viewed, retighten the mount’s R.A. and Dec.
lock knobs.
The object should now be visible somewhere in the telescope’s
finder scope. If it isn’t, use the slow-motion controls to scan
the surrounding area of sky. When the object is visible in the
finder scope, use the slow-motion controls to center it. Now,
look in the telescope’s eyepiece. If the finder scope is properly
aligned, the object should be visible somewhere in the field of
view. Once the object is visible in the eyepiece, use the slow-
motion controls to center it in the field of view.
The Dec. slow-motion control cable can move the telescope a
maximum of 25°. This is because the Dec. slow-motion mech-
anism has a limited range of mechanical travel. (The R.A.
slow-motion mechanism has no limit to its amount of travel.)
If you can no longer rotate the Dec. control cable in a desired
direction, you have reached the end of travel, and the slow-
motion mechanism must be reset. This is done by first rotating
the control cable several turns in the opposite direction from
which it was originally being turned. Then, manually slew the
telescope closer to the object you wish to observe (remember
to first loosen the Dec. lock knob). You should now be able to
use the Dec. slow-motion control cable again to fine adjust the
telescope’s position.
Tracking Celestial Objects
When you observe a celestial object through the telescope,
you’ll see it drift slowly across the field of view. To keep it in
the field, if your equatorial mount is polar aligned, just turn
the R.A. slow-motion control cable clockwise. The Dec. slow-
motion control cable is not needed for tracking. Objects will
appear to move faster at higher magnifications, because the
field of view is narrower.
Optional Electronic Drives for Automatic-Tracking
An optional DC electronic drive can be mounted on the R.A.
axis of the equatorial mount to provide hands-free tracking.
Objects will then remain stationary in the field of view without
any manual adjustment of the R.A. slow-motion control cable.
Understanding the Setting Circles
The setting circles on an equatorial mount enable you to
locate celestial objects by their “celestial coordinates”. Every
object resides in a specific location on the “celestial sphere”
That location is denoted by two numbers: its right ascension
(R.A.) and declination (Dec.). In the same way, every location
on Earth can be described by its longitude and latitude. R.A.
is similar to longitude on Earth, and Dec. is similar to latitude.
The R.A. and Dec. values for celestial objects can be found in
any star atlas or star catalog.
The mount’s R.A. setting circle is scaled in hours, from 1
through 24, with small marks in between representing 10-
minute increments. The numbers closest to the R.A. axis
gear apply to viewing in the Southern Hemisphere, while
the numbers above them apply to viewing in the Northern
Hemisphere.
The Dec. setting circle is scaled in degrees, with each mark
representing 2.5° increments. Values of Dec. coordinates
range from +90° to -90°. The 0° mark indicates the celestial
equator. When the telescope is pointed north of the celestial
equator, values of the Dec. setting circle are positive, while
when the telescope is pointed south of the celestial equator,
values of the Dec. setting circle are negative.
So, the coordinates for the Orion Nebula listed in a star atlas
will look like this:
R.A. 5h 35.4m Dec. –5° 27'
That’s 5 hours and 35.4 minutes in right ascension, and -5
degrees and 27 arc-minutes in declination (there are 60 arc-
minutes in 1 degree of declination).
Before you can use the setting circles to locate objects, the
mount must be correctly polar aligned, and the R.A. setting
circle must be calibrated.The Dec. setting circle has been per-
manently calibrated at the factory, and should read 90° when-
ever the telescope optical tube is parallel with the R.A. axis.
Calibrating the Right Ascension Setting Circle
Identify a bright star in the sky near the celestial equator
(Dec.-=-0°) and look up its coordinates in a star atlas.
1. Loosen the R.A. and Dec. lock knobs on the equatorial
mount, so the telescope optical tube can move freely.
2. Point the telescope at the bright star whose coordinates
you know. Lock the R.A. and Dec. lock knobs. Center the
star in the telescope’s field of view with the slow-motion
control cables.
3. Rotate the setting circle until the metal arrow indicates the
R.A. coordinate listed in the star atlas for the object.
Finding Objects With the Setting Circles
Now that both setting circles are calibrated, look up in a star
atlas the coordinates of an object you wish to view.
Loosen the Dec. lock knob and rotate the telescope until the
Dec. value from the star atlas matches the reading on the
Dec. setting circle. Remember that values of the Dec. setting
circle are positive when the telescope is pointing north of the
celestial equator (Dec. = 0°), and negative when the telescope
is pointing south of the celestial equator. Retighten the lock
knob.
Loosen the R.A. lock knob and rotate the telescope until the
R.A. value from the star atlas matches the reading on the R.A.
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setting circle. Remember to use the upper set of numbers on
the R.A. setting circle. Retighten the lock knob.
Most setting circles are not accurate enough to put an object
dead-center in the telescope’s eyepiece, but they should
place the object somewhere within the field of view of the find-
er scope, assuming the equatorial mount is accurately polar
aligned. Use the slow-motion controls to center the object in
the finder scope, and it should appear in the telescope’s field
of view.
The R.A. setting circle must be re-calibrated every time you
wish to locate a new object. Do so by calibrating the setting
circle for the centered object before moving on to the next
one.
Confused About Pointing the Telescope?
Beginners occasionally experience some confusion about
how to point the telescope overhead or in other directions. In
Figure 1 the telescope is pointed north, as it would be during
polar alignment. The counterweight shaft is oriented down-
ward. But it will not look like that when the telescope is pointed
in other directions. Let’s say you want to view an object that is
directly overhead, at the zenith. How do you do it?
One thing you DO NOT do is make any adjustment to the
latitude adjustment t-bolt. That will nullify the mount’s polar
alignment. Remember, once the mount is polar aligned, the
telescope should be moved only on the R.A. and Dec. axes.
To point the scope overhead, first loosen the R.A. lock knob
and rotate the telescope on the R.A. axis until the counter-
weight shaft is horizontal (parallel to the ground). Then loosen
the Dec. lock knob and rotate the telescope until it is pointing
straight overhead. The counterweight shaft is still horizontal.
Then retighten both lock knobs.
Similarly, to point the telescope directly south, the counter-
weight shaft should again be horizontal. Then you simply
rotate the scope on the Dec. axis until it points in the south
direction.
What if you need to aim the telescope directly north, but at an
object that is nearer to the horizon than Polaris? You can’t do
it with the counterweight down as pictured in Figure 1. Again,
you have to rotate the scope in R.A. so the counterweight
shaft is positioned horizontally. Then rotate the scope in Dec.
so it points to where you want it near the horizon.
To point the telescope to the east or west, or in other direc-
tions, you rotate the telescope on its R.A. and Dec. axes.
Depending on the altitude of the object you want to observe,
the counterweight shaft will be oriented somewhere between
vertical and horizontal.
Figure 6 illustrates how the telescope will look pointed at the
four cardinal directions—north, south, east, and west
The key things to remember when pointing the telescope is
that a) you only move it in R.A. and Dec., not in azimuth or
latitude (altitude), and b) the counterweight and shaft will not
always appear as it does in Figure 1. In fact, it almost never
will!
6. Using Your Telescope
Choosing an Observing Site
When selecting a location for observing, get as far away as
possible from direct artificial light such as street lights, porch
lights, and automobile headlights. The glare from these lights
will greatly impair your dark-adapted night vision. Set up on
a grass or dirt surface, not asphalt, because asphalt radiates
more heat. Heat disturbs the surrounding air and degrades
the images seen through the telescope. Avoid viewing over
rooftops and chimneys, as they often have warm air currents
rising from them. Similarly, avoid observing from indoors
through an open (or closed) window, because the tempera-
ture difference between the indoor and outdoor air will cause
image blurring and distortion.
If at all possible, escape the light-polluted city sky and head
for darker country skies. You’ll be amazed at how many more
stars and deep-sky objects are visible in a dark sky!
“Seeing” and Transparency
Atmospheric conditions vary significantly from night to night.
“Seeing” refers to the steadiness of the Earth’s atmosphere at
a given time. In conditions of poor seeing, atmospheric turbu-
lence causes objects viewed through the telescope to “boil”.
If, when you look up at the sky with just your eyes, the stars
are twinkling noticeably, the seeing is bad and you will be lim-
ited to viewing with low powers (bad seeing affects images at
high powers more severely). Planetary observing may also be
poor.
In conditions of good seeing, star twinkling is minimal and
images appear steady in the eyepiece. Seeing is best over-
head, worst at the horizon. Also, seeing generally gets better
after midnight, when much of the heat absorbed by the Earth
during the day has radiated off into space.
Figure 6. This illustration show the telescope pointed in the the four cardinal directions (a) north, (b) south, (c) east, (d) west. Note that the
tripod and mount have not been moved; only the telescope tube has been moved on the R.A. and Dec. axes.
abcd

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Especially important for observing faint objects is good
“transparency”—air free of moisture, smoke, and dust. All
tend to scatter light, which reduces an object’s brightness.
Transparency is judged by the magnitude of the faintest stars
you can see with the unaided eye (6th magnitude or fainter is
desirable).
One good way to tell if conditions are good is by how many
stars you can see with your naked eye. If you cannot see
stars of magnitude 3.5 or dimmer then conditions are poor.
Magnitude is a measure of how bright a star is, the brighter a
star is, the lower its magnitude will be. A good star to remem-
ber for this is Megrez (mag. 3.4), which is the star in the “Big
Dipper” connecting the handle to the “dipper”. If you cannot
see Megrez, then you have fog, haze, clouds, smog, or other
conditions that are hindering your viewing. (See Figure 7)
Cooling the Telescope
All optical instruments need time to reach “thermal equilibri-
um.” The bigger the instrument and the larger the temperature
change, the more time is needed. Allow at least 30 minutes for
your telescope to cool to the temperature outdoors.
Let Your Eyes Dark-Adapt
Don’t expect to go from a lighted house into the darkness of
the outdoors at night and immediately see faint nebulas, gal-
axies, and star clusters—or even very many stars, for that mat-
ter. Your eyes take about 30 minutes to reach perhaps 80% of
their full dark-adapted sensitivity. As your eyes become dark-
adapted, more stars will glimmer into view and you’ll be able
to see fainter details in objects you view in your telescope.
To see what you’re doing in the darkness, use a red-filtered
flashlight rather than a white light. Red light does not spoil
your eyes’ dark adaptation like white light does. A flashlight
with a red LED light is ideal, or you can cover the front of a
regular incandescent flashlight with red cellophane or paper.
Beware, too, that nearby porch and streetlights and car head-
lights will ruin your night vision.
Eyepiece Selection
By using eyepieces of varying focal lengths, it is possible to
attain many magnifications with the SpaceProbe 3 EQ. The
SpaceProbe 3 EQ comes with two Explorer II eyepieces, a
25mm and a 10mm. These give magnifications of 28x and 70x
respectively. Other eyepieces can be used to achieve higher
or lower powers. It is quite common for an observer to own five
or more eyepieces to access a wide range of magnifications.
This allows the observer to choose the best eyepiece to use
depending on the object being viewed.
To calculate the magnification, or power, of a telescope and
eyepiece combination, simply divide the focal length of the
telescope by the focal length of the eyepiece:
Telescope Focal Length (mm)
Magnification = Eyepiece Focal Length (mm)
For example, the SpaceProbe 3 EQ, which has a focal length
of 700mm, used in combination with the 25mm eyepiece,
yields a power of:
700mm ÷ 25mm = 28x
Every telescope has a useful limit of power of about 2x per
mm of aperture (about 152x for the SpaceProbe 3 EQ). Claims
of higher power by some telescope manufacturers are a mis-
leading advertising gimmick and should be dismissed. Keep
in mind that at higher powers, an image will always be dim-
mer and less sharp (this is a fundamental law of optics). The
steadiness of the air (the “seeing”) will also limit how much
magnification an image can tolerate.
Whatever you choose to view, always start by inserting your
lowest-power (longest focal length) eyepiece to locate and
center the object. Low magnification yields a wide field of
view, which shows a larger area of sky in the eyepiece. This
makes acquiring and centering an object much easier. If you
try to find and center objects with high power (narrow field of
view), it’s like trying to find a needle in a haystack!
Once you’ve centered the object in the eyepiece, you can
switch to higher magnification (shorter focal length eyepiece),
if you wish. This is especially recommended for small and
bright objects, like planets and double stars. The Moon also
takes higher magnifications well.
The best rule of thumb with eyepiece selection is to start with
a low power, wide-field eyepiece, and then work your way up
in magnification. If the object looks better, try an even higher
magnification. If the object looks worse, then back off the mag-
nification a little by using a lower-power eyepiece.
What to Expect
So what will you see with your telescope? You should be able
to see bands on Jupiter, the rings of Saturn, craters on the
Moon, the waxing and waning of Venus, and many bright
deep-sky objects. Do not expect to see any color as you do in
NASA photos, since those are taken with long-exposure cam-
eras and have “false color” added. Our eyes are not sensitive
enough to see color in deep-sky objects except in a few of the
brightest ones.
Remember that you are seeing these objects using your own
telescope with your own eyes! The object you see in your
eyepiece is in real-time, and not some conveniently provided
image from an expensive space probe. Each session with
Figure 7. Megrez connects the Big Dipper’s handle to it’s
“pan”. It is a good guide to how conditions are. If you can not
see Megrez (a 3.4 mag star) then conditions are poor.

your telescope will be a learning experience. Each time you
work with your telescope it will get easier to use, and stellar
objects will become easier to find. Take it from us, there is
big difference between looking at a well-made full-color NASA
image of a deep-sky object in a lit room during the daytime,
and seeing that same object in your telescope at night. One
can merely be a pretty image someone gave to you. The other
is an experience you will never forget!
Objects to Observe
Now that you are all set up and ready to go, one critical deci-
sion must be made: what to look at?
A. The Moon
With its rocky surface, the Moon is one of the easiest and most
interesting targets to view with your telescope. Lunar craters,
marias, and even mountain ranges can all be clearly seen
from a distance of 238,000 miles away! With its ever-chang-
ing phases, you’ll get a new view of the Moon every night.
The best time to observe our one and only natural satellite
is during a partial phase, that is, when the Moon is NOT full.
During partial phases, shadows are cast on the surface, which
reveal more detail, especially right along the border between
the dark and light portions of the disk (called the “terminator”).
A full Moon is too bright and devoid of surface shadows to
yield a pleasing view. Make sure to observe the Moon when it
is well above the horizon to get the sharpest images.
Use an optional Moon filter to dim the Moon when it is very
bright. It simply threads onto the bottom of the eyepieces (you
must first remove the eyepiece from the focuser to attach a
filter). You’ll find that the Moon filter improves viewing com-
fort, and also helps to bring out subtle features on the lunar
surface.
B. The Planets
The planets don’t stay put like the stars, so to find them you
should refer to Sky Calendar at our website (telescope.com),
or to charts published monthly in Astronomy, Sky & Tele-
scope, or other astronomy magazines. Venus, Mars, Jupiter,
and Saturn are the brightest objects in the sky after the Sun
and the Moon. Your SpaceProbe 3 EQ is capable of showing
you these planets in some detail. Other planets may be visible
but will likely appear star-like. Because planets are quite small
in apparent size, optional higher-power eyepieces are recom-
mended and often needed for detailed observations. Not all
the planets are generally visible at any one time.
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
gorgeous two-color double star Albireo in Cygnus are favor-
ites. Defocusing a star slightly can help bring out its color.
D. Deep-Sky Objects
Under dark skies, you can observe a wealth of fascinat-
ing deep-sky objects, including gaseous nebulas, open and
globular star clusters, and a variety of different types of galax-
ies. 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 EQ.
7. Care and Maintenance
If you give your telescope reasonable care, it will last a lifetime.
Store it in a clean, dry, dust free place, safe from rapid chang-
es in temperature and humidity. Do not store the telescope
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 drawtube when not
in use.
Your SpaceProbe 3 EQ telescope requires very little mechani-
cal 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 the appendix
B at the end of this manual for details of how to clean your
telescope’s optics.
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