Ancient Wanderers in Our Modern Sky
+ Von Del Chamberlain +
Ancient astronomers knew seven objects, which they referred to as "planets,"
the wanderers. These were the seven "stars" that constantly changed their
places, ever moving through the band of constellations called the zodiac. We can
see all of these in our sky as we close out November 1997.
Two of the objects that ancient people referred to as planets are no longer
called by that name: today we know that the Sun is actually a star and that we
on Earth orbit it each year. We also know that the Moon orbits us each month as
it moves with us about the Sun each year. Thus, we grow up thinking of the Moon
and Sun quite differently than ancient people did. Even though they do move
around the zodiac, we no longer include the Sun and Moon on our list of
Our knowledge about the remaining five planets has also changed dramatically.
We know Mercury, Venus, Mars, Jupiter and Saturn as bodies belonging to the
Sun's orbiting fleet of worlds, including Earth, and we have discovered three
additional ones: Uranus, Neptune and Pluto. Actually we have discovered many
more than this if we want to include the numerous minor planets, or asteroids,
orbiting the Sun and natural satellites orbiting most of the planets.
What a sky we have in late November this year! In addition to the majestic
stars that have recently come into the eastern sky, and the Moon that monthly
cycles through the heavens, we can enjoy the ancient list of planets. After the
Sun sets, the five planets--Mercury, Venus, Mars, Jupiter and Saturn--are in our
evening sky. Go out. Look around, and find them for yourself.
Let's begin with the brightest and easiest to locate. Venus is difficult to
miss if you are outside as it gets dark. Just look toward the southwest and it
will "knock your eye out." It is so bright right now that some people call
police stations, planetariums, observatories and talk-radio stations to inquire
about and report on the "UFO" they see every evening." As you look at Venus, it
is easy to realize why all ancient people paid so much attention to this most
magnificent of celestial objects.
Just to the lower right of Venus, much dimmer and redder, is Mars. This
planet has always intrigued humankind. Once it was labeled "God of War," then
when telescopes became available people thought they could see canals on Mars
and they began to imagine a civilization there. Some invented stories of
Martians invading Earth, among the best known science fiction of all time.
Although the canals have faded from our understanding, we now know that our
smaller neighbor is not entirely unlike our own planet. We have recognized
gigantic canyons, a huge volcanic mountain, impact craters, polar caps with
frozen water, many features indicating that water has flowed upon the Martian
surface, and we have seen clouds in the thin atmosphere. Our increased knowledge
has certainly not diminished our desire to go to Mars. It is a world waiting for
voyages of exploration that should prove as exciting as any known before. Mars
is slowly disappearing from our evening sky, but will remain visible for several
weeks to those who take the time to watch it.
The most elusive of the five evening planets is Mercury. For most of the next
two weeks is will be possible to see Mercury if you find a suitable place and
watch with patience. The planet will be visible only briefly, very low in the
southwest, following the Sun down. Watch to the lower right of Venus as the sky
begins to darken after sunset. Mercury will be three to four times farther from
Venus than Mars is, considerably lower and farther to the right. The mountainous
terrain we have here in Utah makes viewing Mercury more difficult. It would be
best to observe from a place with a low horizon toward the southwest, but most
Utahns should be able to see Mercury by watching closely on clear evening skies
between now and December 7. Mercury is bright enough to see easily. The problem
is that it sets soon after sunset. Binoculars will help locate it in the
Jupiter is very easy to locate off to the south, about 25 degrees left of
Venus. Although not as brilliant as Venus, Jupiter is bright and easy to spot.
It is in the constellation Capricornus, composed of dim stars. Even a small
telescope reveals several of the many satellites of Jupiter. Watch over coming
weeks as this giant gas planet moves off toward the sunset.
Yet another bright planet is easy to spot after dusk. Saturn is in the
southeast, brightest object in that part of the sky. Through a telescope, its
beautiful rings can be seen, along with several of its more than two-dozen
Right now the Moon is a waning crescent in our morning sky. It will be new on
November 29, then become visible as a waxing crescent in the evening sky to
issue in the month of December.
Once you have found the impressive set of ancient wanderers, the planets, in
our current sky, notice how they lie along an approximate line going from
southwest toward the east. These bright punctuation marks reveal the celestial
pathway named the zodiac, the band of constellations that so intrigued people in
ages past. The dance of planets through these constellations inspired all sorts
of ideas in fertile human minds. Even today, some still cling to astrological
predictions and prognostications based upon the locations and movements of the
Sun, Moon and planets through the zodiac, ideas born in ages of ignorance, ideas
so attractive that they will probably continue to be believed as long as humans
are around. Others, not as easily persuaded by "ancient" sensational beliefs,
will enjoy our continuing exploration of the planetary worlds that accompany us
in our flight around a star and with that star through the Galaxy and onward
into intergalactic depths.
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