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Skyguide
October to December 2000
Bing F. Quock
October 13
How often does a Full Moon fall on Friday the 13th? It does this month
at 1:54 a.m., pdt. Look for that big, orange, pumpkin-like orb when it
rises an hour after sunset tonight. This Full Moon is known as the "Hunter's
Moon."
October 27 Since
this is the last Sunday in October, most of the United States returns
to Standard Time and the hour between 1 and 2 a.m. repeats. October 29
New Moon, known to the Cheyenne as "Time When the Cherries are
Ripe" and to the Tlingit as the "Moon When All Kinds of Animals
Prepare Their Dens."
November 11
Full Moon, located near Saturn against the stars of Taurus. The Oto called
this the "Every Buck Loses His Horns Moon."
November 17 Peak of
the Leonid meteor shower, usually averaging about 15 meteors per hour.
Although they were spectacular in 1998 and 1999, they’re not expected
to match that performance this year.
November 25 New
Moon at 3:12 p.m. pst. By sunset, the young Moon is only a few hours
old and still too near the Sun to see. Try at sunset tomorrow (the 26th).
Naked-eye sighting of the first young crescent after this date will
mark the start of Ramadan, the Muslim month of fasting.
December 11
Full Moon, located at the feet of Gemini. Nicknamed the “Moon Before Yule”
by Colonials, it was called the “Big Freezing Moon” by the Cheyenne. Being
nearest the win- ter solstice and directly opposite the Sun, it follows
a long, high arc across the sky, while the winter sun arcs low.
December 13 Peak
of the Geminid meteor shower. Usually the best meteor shower of the
year, this year’s Geminids are washed out by the light of a bright,
waning gibbous Moon. Otherwise, you’d see about 50 meteors per hour.
December 16
Summer Solstice, for Martians (if there are any) on the northern hemisphere
of the Red Planet.
December 21 Winter
Solstice (on Earth) at 5:37 a.m. pst. The Sun rises and sets at its most
southerly points and makes a short, low arc across the sky. For those
living south of the equator, it's the summer solstice.
December 25
New Moon, causing a partial solar eclipse. Observers in San Francisco
will see the eclipse start minutes after sunrise, with mid-eclipse at
8:21 a.m. pst, when 18 percent of the Sun’s diameter will be hidden
from view by the silhou- ette of the Moon. Times and percent of obscuration
will vary with location (see box).
Mercury
At the beginning of October,
this little planet is low in the west at sunset, having appeared out
of the Sun’s glow in mid-September. However, at this time of the year,
the angle of the planets' paths from one side of the Sun to the other
is quite shallow with respect to the horizon. This places Mercury very
low, even when it’s at its greatest angular separation from the Sun
(elongation) on October 6. The Moon can be used to find Mercury the
evening of September 29 (Mercury is about seven degrees below the Moon,
with brighter Venus to the left) and on the morn- ing of November 24
(Mercury three degrees to the right of the Moon).
Venus
This impressively bright
planet is an evening object through the end of the year, starting off
in October low in the west after sunset and climbing higher until it
reaches a commanding altitude in December. The waxing crescent Moon
makes for a series of striking sights as it passes close to Venus on
the evenings of October 29 and 30, much closer on November 29, and again
on December 29.
Mars
The Red
Planet is a morning object this quarter, located against the constellation
Leo. Having passed the bright star Regulus in mid-September, it passes
into Virgo in late October. As it rises earlier each morning, it gradually
moves southward, passing Virgo’s brightest star, Spica, in mid-December.
Jupiter
The largest planet in our
solar system rises a few hours after sunset at the beginning of October.
It gradually rises earlier each night against the stars of Taurus. Take
this opportunity to contrast its creamy white color with that of thenearby
red star Aldebaran—the eye of Taurus. Currently “in retro grade,” Jupiter
is moving westward against the stars and is slowly approaching the beautiful
Pleiades star cluster. The giant planet is at opposition on November
27 and rises in the east at sunset. It can then be seen all night long.
The Moon passes nearby on the evenings of October 16 (forming an equilateral
triangle with Jupiter and Aldebaran as it rises), November 12 (Moon
in-line between Jupiter and Aldebaran), and December 9.
Saturn
As Jupiter slowly pulls away
from it, the Ringed Planet retrogrades westward through the stars of
Taurus, starting near the Pleiades. Saturn is at opposition on November
19, becoming brighter than it has been in more than 25 years. The waning
gibbous Moon can be found nearby on Octo- ber 15 and November 11 (each
time, look for two pairs of objects: Saturn/the Moon and Jupiter/Aldebaran),
and on December 8 and 9.
|
Sunrise |
Local Noon |
Sunset |
| October 1 |
7:06 a.m. pdt |
12:59 p.m. pdt |
6:52 p.m. pdt |
| November 1 |
6:36 a.m. pst |
11:53 a.m. pst |
5:10 p.m. pst |
| December 1 |
7:07 a.m. pst |
11:59 a.m. pst |
4:51 p.m. pst |
| January 1 |
7:25 a.m. pst |
12:13 p.m. pst |
5:01 p.m. pst |
| Times indicated are for San Francisco,
CA, and are accurate to within two minutes. |
| Caveat Spectator |
|
Among the many reasons that most Americans will rise early on December
25 is that morning's partial eclipse of the Sun. This eclipse will
be seen only from North America—at dawn on the West Coast,
noon along a southeasterly bound swath from Lake Erie to the Florida
peninsula, and sunset in Newfoundland. The most northerly observers
will see about 70 percent of the Sun's diameter blocked from view;
more southerly viewers will see less. But let the observer beware.
The hazards of looking directly at the Sun can't be emphasized enough.
Owing to the Sun's brightness, viewing it without taking the proper
precautions can result in irreparable eye damage. The safest real-time
view of the eclipse will most likely be by webcast. Alternatively,
several methods of projecting images of the Sun will allow observers
to watch safely. Only a few types of professionally made filters
have been certified as safe for direct solar viewing. Do not try
to make a "solar filter" from common household materials--no
matter how good you think it is, it won't be good enough! For safe
solar-watching advice, contact your local planetarium, science museum,
or amateur astronomy lab.
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Bing Quock is a member of the Morrison Planetarium
Staff. bquock@calacademy.org
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Fall 2000
Vol. 53:4
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