Instruction Manual

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APPENDIX D:
Basic Astronomy
In the early 17th century Italian Scientist Gali-
leo, using a telescope smaller than your LX70,
turned it skyward instead of looking at the dis-
tant trees and mountains. What he saw, and
what he realized about what he saw, has for-
ever changed the way mankind thinks about
the universe. Imagine what it must have been
like being the first human to see moons revolve
around the planet Jupiter or to see the changing
phases of Venus! Because of his observations,
Galileo correctly realized Earth’s movement and
position around the Sun, and in doing so, gave
birth to modern astronomy. Yet Galileo’s tele-
scope was so crude, he could not clearly make
out the rings of Saturn. Galileo’s discoveries
laid the foundation for understanding the motion
and nature of the planets, stars, and galaxies.
Building on his foundation, Henrietta Leavitt de-
termined how to measure the distance to stars,
Edwin Hubble gave us a glimpse into the pos-
sible origin of the universe, Albert Einstein un-
raveled the crucial relationship of time and light,
and 21st-century astronomers are currently
discovering planets around stars outside our
solar system. Almost daily, using sophisticated
successors to Galileo’s telescope, such as the
Hubble Space Telescope and the Chandra X-
Ray Telescope, more and more mysteries of the
universe are being probed and understood.
We are living in the golden age of astronomy.
Unlike other sciences, astronomy welcomes
contributions from amateurs. Much of the
knowledge we have on subjects such as com-
ets, meteor showers, double and variable stars,
the Moon, and our solar system comes from
observations made by amateur astronomers.
So as you look through your Meade telescope,
keep in mind Galileo. To him, a telescope was
not merely a machine made of glass and metal,
but something far more—a window of incred-
ible discovery. Each glimpse offers a potential
secret waiting to be revealed.
Objects in Space Listed below are some of the
many astronomical objects that can be seen
with your telescope:
The Moon is, on average, a distance of 239,000
miles (380,000km) from Earth and is best ob-
served during its crescent or half phase when
Sunlight strikes the Moon’s surface at an angle.
It casts shadows and adds a sense of depth
to the view. No shadows are seen during a full
Moon, causing the overly bright Moon to ap-
pear flat and rather uninteresting through the
telescope. Be sure to use a neutral Moon filter
when observing the Moon. Not only does it pro-
tect your eyes from the bright glare of the Moon,
but it also helps enhance contrast, providing a
more dramatic image. Using your telescope,
brilliant detail can be observed on the Moon,
including hundreds of lunar craters and Maria,
described below.
Craters are round meteor impact sites cover-
ing most of the Moon’s surface. With no atmo-
sphere on the Moon, no weather conditions ex-
ist, so the only erosive force is meteor strikes.
Under these conditions, lunar craters can last
for millions of years.
Maria (plural for mare) are smooth, dark areas
scattered across the lunar surface. These dark
areas are large ancient impact basins that were
filled with lava from the interior of the Moon by
the depth and force of a meteor or comet im-
pact. Twelve Apollo astronauts left their boot
prints on the Moon in the late 1960’s and early
1970’s. However, no telescope on Earth is able
to see these footprints or any other artifacts.
In fact, the smallest lunar features that may be
seen with the largest telescope on Earth are
about one-half mile across.
Planets change positions in the sky as they or-
bit around the Sun. To locate the planets on a
given day or month, consult a monthly astron-
omy magazine, such as Sky and Telescope or
Astronomy. Listed below are the best planets
for viewing through the LX70 telescope.
Venus is about nine-tenths the diameter of
Earth. As Venus orbits the Sun, observers can
see it go through phases (crescent, half, and
full) much like those of the Moon. The disk of
Venus appears white as Sunlight is reflected off
the thick cloud cover that completely obscures
any surface detail.
Mars is about half the diameter of Earth, and ap-
pears through the telescope as a tiny reddish-
orange disk. It may be possible to see a hint
of white at one of the planet’s Polar ice caps.
Approximately every two years, when Mars is
closest to Earth in its orbit, additional detail and