7
4.) Filtered compressed air may be used to remove surface dust from lenses and mirrors. Remove
the dust cap and the dew shield. Once removed, point the can away from the lens and gently expel
some air and any condensation or dust that has accumulated on the discharge tube. Spray the lens
or mirror with short bursts of air to carefully remove the dust particles. DO NOT HOLD THE TRIGGER
OF THE COMPRESSED AIR CAN FOR EXTENDED PERIODS BECAUSE PROPELLANT FROM THE CAN
MIGHT ESCAPE AND DAMAGE THE OPTICAL SURFACE.
If, after several attempts, you cannot remove the particles, take the telescope to an optical
professional for cleaning.
If you keep the dust caps on your telescope when it is not in use and avoid handling the lenses or
mirrors, only minimal optical maintenance of your telescope should be required. Extensive cleaning is
usually only necessary every few years.
WHAT TO LOOK FOR IN THE SKY:
There is a whole universe of objects you could view at night, so where do you start? We recommend
starting with the most prominent objects first.
The moon
The moon is the easiest target to find at night. When the moon is in full position, it bathes the night
with a silvery light that washes the sky of all but the brightest objects. The best time to view the
moon is not when it is full, but rather when it is less than half full. The dividing line between dark and
light on the moon, called the terminator, shows the best detail in the craters and mountains.
The planets
The planets, our solar system companions, range in size from moon-size rocky bodies to giant gas
balls, which could hold Earth 1000 times over. To find the planets, you will need information about
their times of visibility. An astronomy magazine will give you the locations of the planets, as they
change position from month to month. The Internet is also an excellent source of information,
starcharts, maps, and more! The popular and more familiar constellations often provide the easiest
landmarks to help find the planet’s locations and paths of orbit. Most people have looked up at night
and seen some of the planets without even realizing it. A planet appears like a bright star but does
not twinkle like a star; it will look like a tiny ball. Venus, Mars, Jupiter, and Saturn, are the easiest
planets to view. Mercury is dimmer, usually below the horizon, and is more challenging to find.
Each of the planets provides interesting views. Venus is covered with clouds so all that is visible is an
extremely bright light, the brightest next to the moon. Venus, like the moon, goes through phases,
however. As it travels around the sun, different areas of the planet’s surface are illuminated,
producing crescent shapes of varying size. Mars is the red planet. When it is above the horizon, it is
noticeably red and stands out like a beacon in the night sky. The apparent brightness of Mars varies
as the planet orbits around the sun and throughout its period of visiblity, it will brighten and dim
depending on how near or far it is from Earth.
