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 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. 8), 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 you
may not see many features on the surface of
Saturn, its ring structure will steal your
breath away. You will probably be able to see
a black opening in the rings, known as the
Cassini band.
Saturn is not the only planet that has rings,
but it is the only set of rings that can be
seen with a small telescope. Jupiter’s rings
cannot be seen from Earth at all—the
Voyager spacecraft discovered the ring after
it passed Jupiter and looked back at it. It
turns out, only with the sunlight shining
through them, can the rings be seen. Uranus
and Neptune also have faint rings.
Optional color filters help bring out detail
and contrast of the planets. Meade offers a
line of inexpensive color filters.
What’s Next? Beyond the Solar System
:
Once you have observed our own system of
planets, it’s time to really travel far from
home and look at stars and other objects.
You can observe thousands of stars with
your telescope. At first, you may think stars
are just pinpoints of light and aren’t very
interesting. But look again. There is much
information that is revealed in stars.
ASTRONOMY RESOURCES
•
The Meade 4M Community
6001 Oak Canyon, Irvine, CA 92618
•
Astronomical League
Executive Secretary
5675 Real del Norte, Las Cruces, NM 88012
•
The Astronomical Society of the Pacific
390 Ashton Ave., San Francisco, CA 94112
•
The Planetary Society
65 North Catalina Ave, Pasadena, CA 91106
•
International Dark-Sky Association, Inc.
3225 N. First Avenue, Tucson, AZ 85719-2103
The first thing you will notice is that not
all stars are the same colors. See if you
can find blue, orange, yellow, white and
red stars. The color of stars sometimes
can tell you about the age of a star and the
temperature that they burn at.
Other stars to look for are multiple stars.
Very often, you can find double (or binary)
stars, stars that are very close together.
These stars orbit each other. What do you
notice about these stars? Are they
different colors? Does one seem brighter
than the other?
Almost all the stars you can see in the sky
are part of our galaxy. A galaxy is a large
11
Looking at or near the
Sun
will cause
irreversible
damage to your eye. Do not point this telescope at or near the Sun. Do not look through the telescope as it is moving.
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