On New Years Eve
the Lord of the Rings will be closer to Earth and
brighter than at any time in three decades. All month
long skywatchers can enjoy Saturn at its finest. A
similar opportunity won't come again for another 30
years.
If in 2003 we had the Summer of Mars, this will be the
Winter of Saturn.
On Dec. 31, Saturn will be opposite the Sun in relation
to Earth. That means from our planet, Saturn will rise as
the Sun sets, reaching its highest point in the southern
sky at midnight and setting as the Sun rises. Astronomers
call this opposition.
Saturn takes 29.42 years to orbit the Sun. Its path is
not quite circular, and it was just on July 26 that
Saturn reached its closest point to the Sun on that
orbit, called perihelion. The near coincidence of
perihelion and opposition dictate that on New Years Eve,
Saturn will be closer to Earth than at any time since
December 1973.
The ringed planet will be 748.3 million miles (1.2
billion kilometers) from Earth. It will not come closer
until January of 2034. Contrast this year's event to
another opposition, in June 2018, when Saturn will get no
closer than 841 million miles, or almost 100 million
miles farther away.
There's a bonus. Saturn's rings are not always well
tilted for viewing. Sometimes they are edge on, as seen
from Earth, and unimpressive.
Right now, the rings are still dramatically tipped --
more than 25 degrees to our line of sight. This allows
the planet to be seen in all its glory, and it also
accentuates Saturn’s brightness.
By the end of December, Saturn will be shining as bright
as it can ever get, at magnitude –0.5. Among the
stars, only Sirius and Canopus are brighter.
Finding Saturn
With a simple sky map, Saturn is easy to find right now.
It is currently in the constellation of Gemini, the
Twins. Were we to use the popular tracing conceived by
H.A. Rey, of "two matchstick men holding
hands," Saturn is found between the legs of the
twins.
Early on Wednesday evening, Dec. 10, Saturn will be the
very bright yellowish-white "star" hovering to
the lower right of a waning gibbous Moon as they rise out
of the east-northeast part of the sky.
Saturn is the telescopic showpiece of the night sky,
thanks to its great ring system in all of its icy,
glimmering elegance. In small telescopes, the rings
surprise even veteran observers with their chilling
beauty. Certainly they will delight anyone this winter
who might receive a telescope as a holiday gift.
Any telescope magnifying more than 30x will show them.
Even most inexpensive department store telescopes should
do the job (though if you're thinking about buying a
telescope, you'll want to learn more and become a
discerning buyer -- there's a lot of junk on the market.)
The children of
Saturn
Galileo Galilei (1564-1642) was the first to view the
rings, in 1610. Although what he saw through his crude
telescope left him completely baffled, as Saturn appeared
to him not to have rings but rather two smaller bodies
flanking it, one on either side. He couldn’t make
them out clearly and thought that Saturn was a triple
body, two small orbs attached to a large one.
Later, when the rings turned edgewise to Earth and the
two companions disappeared, Galileo invoked an ancient
myth when he wrote, "Has Saturn swallowed his
children?" Galileo lamented that his mind was too
weak to comprehend this strange phenomenon.
Actually, it was his telescope that was too weak; a
better one would have revealed Saturn’s companions
as rings. It was not until a young Dutch mathematician,
Christian Huygens (1629-1695) utilized a much better
telescope, and on March 25, 1655 saw the rings for what
they really were.
In mythology, Saturn closely resembled the Greek god
Cronus, but he’s more usually recognized as the
Roman god of agriculture.
The name is related to both the noun satus (seed corn)
and the verb serere (to sow). But why would the planet
Saturn be linked to agriculture? Perhaps a clue can be
found from the ancient Assyrians who referred to Saturn
as lubadsagush, which translated, meant "oldest of
the old sheep."
Possibly this name was applied because Saturn seems to
move so very slowly among the stars, compared to nearer
planets that shift their seasonal positions in the sky
more quickly. It may have also reminded sky watchers of
the slow gait of plowing oxen or cattle.
Closer views of Saturn are slated for next year. NASA's
Cassini spacecraft will arrive at the ringed planet and
is expected to produce the best images and data ever
collected of the sixth planet from the Sun.
any
questions you would like answered about the night sky in
the next column
