circular pattern around our Sun. Any
system of planets orbiting one or more
stars is called a solar system. Our Sun,
by the way, is a single, yellow dwarf
star. It is average as far as stars go and is a
middle aged star.
Beyond the planets are clouds of comets, icy
planetoids and other debris left over from the
birth of our sun. Recently astronomers have
found large objects in this area and they may
increase the number of planets in our solar
system.
The four planets closest to the Sun are rocky
and are called the inner planets. Mercury,
Venus, Earth and Mars comprise the inner
planets. Venus and Mars can be easily seen
in your telescope.
Venus is seen before dawn or after sunset,
because it is close to the Sun. You can
observe Venus going through crescent
phases. But you cannot see any surface
detail on Venus because it has a very thick
atmosphere of gas.
When Mars is close to the Earth, you can
see some details on Mars, and sometimes
even Mars’ polar caps. But quite often, Mars
is further away and just appears as a red dot
with some dark lines crisscrossing it.
Jupiter, Saturn, Uranus, Neptune and Pluto
comprise the outer planets. These planets,
except for Pluto, are made mostly of gases
and are sometimes called gas giants. If they
had grown much bigger, they may have
become stars. Pluto is made mostly of ice.
Jupiter is quite interesting to observe. You
can see bands across the face of Jupiter. The
more time you spend observing these bands,
the more details you will be able to see.
One of the most fascinating sights of Jupiter
are its moons. The four largest moons
are called the Galilean moons, after the
astronomer Galileo, who observed them for
the first time. If you’ve never watched the
Galilean moons in your telescope before,
you’re missing a real treat! Each night, the
moons appear in different positions around
the Jovian sky. This is sometimes called
the Galilean dance. On any given night,
you might be able to see the shadow of a
moon on the face of Jupiter, see one moon
eclipse another or even see a moon emerge
from behind Jupiter’s giant disk. Drawing
SURF THE WEB
• The Meade 4M Community:
http://www.meade4m.com
• Sky & Telescope:
http://www.skyandtelescope.com
• Astronomy:
http://www.astronomy.com
• Astronomy Picture of the Day:
http://antwrp.gsfc.nasa.goc/apod
• Photographic Atlas of the Moon:
http://www.lpi.ursa.edu/research/lunar_orbiter
• Hubble Space Telescope Public Pictures:
http://oposite.stsci.edu/pubinfo/pictures.html
the positions of the moons each night is an
excellent exercise for novice astronomers.
Any small telescope can see the four
Galilean moons of Jupiter (Fig. 9), plus a few
others, but how many moons does Jupiter
actually have? No one knows for sure! Nor
are we sure how many Saturn has either. At
last count, Jupiter had over 60 moons, and
held a small lead over Saturn. Most of these
moons are very small and can only be seen
with very large telescopes.
Probably the most memorable sight you will
see in your telescope is Saturn. Although
Looking at or near the
Sun
will cause
irreversable
damage to your eye. Do not point this telescope at or near the Sun. Do not look through the telescope as it is moving.
12
