Celestial Observing; Observing The Moon; Observing The Planets - Celestron STAR HOPPER Instruction Manual

As you can see, before determining the field of view, you must calculate the magnification. Using the example above,
we can determine the field of view using the same 25mm eyepiece. The 25mm SMA eyepiece has an apparent field
of view of 52°. Divide the 52° by the magnification, which is 49 power. This yields an actual field of 1.06°, or a
little over a degree. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron
Accessory Catalog (#93685).

CELESTIAL OBSERVING

Now that your telescope is set up, you're ready to use it for observing. This section covers visual observing for both
solar system and deep-sky objects.

Observing the Moon

In the night sky, the moon is a prime target for your first look because it is extremely bright and easy to find.
Although the beauty of the full moon may make it seem a perfect viewing object, in fact, the light reflected from its
fully illuminated face can be overpowering. In addition, little or no contrast can be seen during this phase.
One of the best times to observe the moon is during its partial phases, such as a crescent or quarter moon. At these
times, long shadows reveal a great amount of detail on the lunar surface. At low power, with the standard eyepiece,
you'll be able to see the whole lunar disk at one time. Change to higher power (magnification) with an optional
eyepiece to focus in on a smaller area. Keep in mind that the rotation of the earth will cause the moon to drift out of
your field of view. You'll have to manually adjust the telescope to keep the moon centered. This effect is more
noticeable at higher power. Consult a current astronomy magazine or your local newspaper to find out the current
phase of the moon.
Lunar Observing Hint
To increase contrast and bring out visible detail on the lunar surface, try using different filters (available through
your local Celestron dealer). A yellow filter works well for improving contrast.

Observing the Planets

Other easy targets include the five "naked eye" planets of our solar system, so called because they can be spotted in
the night sky by the unaided eye. You can see Venus go through its lunar-like phases. Mars can reveal a host of
surface detail and one, if not both, of its polar caps. You'll be able to see the cloud belts of Jupiter, perhaps even the
great Red Spot. In addition, you'll be able to see the moons of Jupiter as they orbit the giant planet. Saturn, with its
beautiful rings, is easily visible at moderate power, as is Mercury. All you need to know is where to look. Most
astronomy publications indicate where the planets are in the sky each month.
This drawing of Jupiter provides a good representation of what you can expect to see with moderate
magnification, during good "seeing" conditions.
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