SKYWATCHERS
NEWSLETTER OF THE CHINA LAKE ASTONOMICAL SOCIETY
Volume 40 No. 7 July 1, 2003
NEXT MEETING 7:30 p.m., Monday, July 7, 2003
Maturango Museum, 100 East Las Flores Avenue, Ridgecrest, California
JULY 7 MEETING :
Gary Peterson will return to CLAS for our July 7 program. Dr. Peterson,
a geologist at San Diego State University has talked to us about several
topics related to planetary geology in previous years. This year he will
focus on the difference between Earth and our sister planet, Venus.
Despite the large scale similarities between the two planets, Venus has a
much different atmosphere and surface conditions than Earth. There are
few explanations of why there are such significant differences, but it is
likely that we will hear some on July 7.
DATES TO KEEP IN MIND
Monday, July 7, 2003: Regular CLAS Meeting at the Maturango Museum in
Ridgecrest, 7:30 p.m.
Wednesday, July 23. 2003: Deadline for next Skywatchers Newsletter
Friday, July 25, 2003 - Star Party, see below.
Monday, August 4, 2003: Regular CLAS Meeting at the Maturango Museum in
Ridgecrest, 7:30 p.m.
STAR PARTY SCHEDULE FOR THE 2003 SEASON:
Star Parties will be held on the dates listed below. Star Parties are an
activity where members and guests join together to share views of the
skies. If you have a telescope, bring it. If not, come and look through
someone else's. Star parties are held at a site in the open desert south
of Ridgecrest. To reach the star party site from Ridgecrest, go south on
China Lake Boulevard 6.5 miles from its intersection with Ridgecrest
Boulevard. Continue straight across Highway 395 and you will be on Brown
Road (Old Highway 395). Follow Brown Road as it curves to the right and
goes west. After 2.3 miles there will be a 30-inch orange cone on the
left. Turn left and follow the dirt road marked by 12-inch cones. The
CLAS Star party is 0.5 miles along this road. Watch for signs and cones,
which will be put out about a half-hour before viewing starts. Call
Carroll Evans 760-375-5681, or Bruce Churchill 760-375-7247, for more
information.
Friday, July 25--Signs out at 8:30 p.m., Star viewing at 9:00 p.m.
Friday, August 29--Signs out at 8:00 p.m., Star viewing at 8:30 p.m.
Friday, September 26--Signs out at 7:00 p.m., Star viewing at 8:00 p.m.
Friday, October 24--Signs out at 6:30 p.m., Star viewing at 7:00 p.m.
Friday, November 21--Signs out at 6:30 p.m., Star viewing at 7:00 p.m.
BRIEF ASTRONOMICAL CALENDAR FOR JULY 2003 (David Hollingsworth)
July 2 Midpoint of the year at midday (13:00 Daylight-Saving Time
if counting by local clock time).
July 6 First-quarter Moon.
July 13 Full Moon.
July 21 Last-quarter Moon.
July 28 Southern Delta Aquarid meteor shower peaks.
July 29 New Moon at 3:26 PDT.
OBSERVING IN JULY 2003 (David Hollingsworth)
With the Full Moon on the 13th, the best evening deep sky observing will
be on the 1st through the 3rd and the 21st through the end of the month.
On Friday, the 25th, the night of the CLAS star party, the Sun sets at
20:03 PDT and the end of astronomical twilight is not until 21:46. So
observing of faint objects will start late in the evening. Unless
otherwise stated, descriptions that follow are for observing on the 25th
from Ridgecrest.
Planets: Jupiter is disappearing in the west. Mars has become the main
attraction, enlarging in size from 16" to 22" (the biggest since 1988) and
brightening to -2.3 by month's end. Mars (in Aquarius) rises around 23:30
in the beginning of the month and at about 22:00 at the end of the month,
so there will be only low altitude views before midnight. The best
viewing of Mars will still be in the dark morning hours between 3:00 and
4:00 as it reaches its highest altitude in the south. At this time,
Uranus (5.7, in Aquarius) and Neptune (7.8, in Capricornus) are nearby
and will also be placed for best detection in the south (see the April S&T
for finder charts). Venus and Saturn are seen low in the east before
sunrise. By month's end, Venus becomes lost in morning twilight, but
Saturn rises about 2 1/2 hoursbefore sunrise.
Binocular and Telescope Highlights: Starting to sink in the west, near the
Milky Way's galactic north pole, is the bright 80-member open cluster Mel
111 (Coma Berenices Star Cluster). Lying about 6: (about a binocular
field) east of Mel 111 is 31 Com (magnitude 4.93), which very closely
marks the Milky Way's galactic North Pole. Our Milky Way's galactic
center is about one binocular field north of M 7, or about a third of the
way between M 6 (Butterfly Cluster) and M 8 (Lagoon Nebula), both of which
can be seen naked eye lying along the west edge of the bright band of
Milky Way stars rising out of the southern horizon in Scorpius and
Sagittarius. I'm unashamedly repeating past recommendations. Hours
should be spent (with charts in hand) scanning the southern Milky Way's
dense star fields: open clusters, globular clusters, planetary nebulae,
dark absorption nebulae, and bright emission nebulae abound. One of my
favorite sights is the "False Comet" (NGC 6213 + Tr 24), lying in the
southwestern curve of Scorpius' "fish hook" shaped string of stars.
Another favorite is the single-field combination of NGC 6520 (OC of hot
young blue stars) and a dark absorption nebula B 86 (Ink Spot Nebula).
This fine combination lies about half way between Gamma Sgr (the tip of
the Teapot's spout) and M 8. (See a detailed photograph of NGC 6520/B 86
and the dense star field lying just above the Teapot on the July page of
the RASC Observer's Calendar.) In the west, globular clusters M5 (in
Serpens), M3 (in Canes Venatici), and M13 (Hercules Cluster) are worth
checking out for comparison views. The handle of the Big Dipper is still
high in the northwest, so views of M51should be good.
Comets: During the first three days of July, C/2002 O7 LINEAR (mag. 10)
may be spotted about 25: high in eastern Leo, about 2: west of Theta
Leonis. Unfortunately, this viewing opportunity window closes after that,
as it drops lower each night while the waxing crescent Moon gets brighter.
ASTRONOMICAL INFORMATION VIA EARL TOWSONMARS IS NEARLY HERE!
Everyone on Earth is hurtling toward Mars at 25,000
mph. Amateur astronomers report that the red planet is now so close, you
can see its south polar cap through a backyard telescope. The view will
only get better in the weeks ahead as Earth and Mars converge for a close
encounter on August. Markings then will become clearer in the weeks
ahead. On June 1st Mars was 12.5 arcseconds across and it glowed like a
-1st magnitude star. On August 27th it will be twice as wide (25
arcseconds) and six times brighter (magnitude -2.9). Much has been made of
the fact that the August 27th encounter with Mars is the closest in some
60,000 years. Neanderthals were the last to observe Mars so favorably
placed. This is true. It's also a bit of hype. Mars and Earth have been
almost this close many times in recent history.
http://science.nasa.gov/headlines/y2003/18jun_approachingmars.htm
PLUTO 25 YEARS LATER: On 22 June 1978, an astronomer at the U.S. Naval
Observatory in Washington, D.C. was making routine measurements of
photographic plates taken with the 1.55-meter (61-inch) Kaj Strand
Astrometric Reflector at the USNO Flagstaff Station in Arizona. The
purpose of these images was to refine the orbit of the far-flung planet
Pluto to help compute a better ephemeris for this distant object.
Astronomer James W. Christy had noticed that a number of the images of
Pluto appeared elongated, but images of background stars on the same plate
did not. Other plates showed the planet as a tiny, round dot. Christy
examined a number of Pluto images from the USNO archives, and he noticed
the elongation again. Furthermore, the elongation appeared to change
position with respect to the stars over time. After eliminating the
possibility that the elongation was produced by plate defects and
background stars, the only plausible explanation was that it was caused by
a previously unknown moon orbiting Pluto at a distance of about 19,600
kilometers (12,100 miles) with a period of just over six days. On 7 July
1978, the discovery was formally announced to the astronomical community
and the wor ld by the IAU Central Bureau for Astronomical Telegrams via
IAU Circular 3241. The discovery received the provisional designation
"1978 P 1"; Christy proposed the name "Charon", after the mythological
ferryman who carried souls across the river Acheron, one of the five
mythical rivers that surrounded Pluto's underworld. Over the course of the
next several years, another USNO astronomer, the late Robert S.
Harrington, calculated that Pluto and its newly-found moon would undergo a
series of mutual eclipses and occultations, beginning in early 1985. On 17
February 1985 the first successful observation of one of these transits
was made at with the 0.9-meter (36-inch) reflector at the University of
Texas McDonald Observatory, within 40 minutes of Harrington's predicted
time. The IAU Circular announcing these confirming observations was issued
on 22 February 1985. With this confirmation, the new moon was officially
named Charon. The discovery of Charon has led to a much better
understanding of just how tiny Pluto is. Its diameter is about 2274 km
(1413 miles), and its mass is 0.25% of the mass of the Earth. Charon has a
diameter of about 1172 kilometers (728 miles) and a mass of about 22% that
of Pluto. The two worlds circle their common center of mass with a period
of 6.387 days and are locked in a "super-synchronous" rotation: observers
on Pluto's surface would always see Charon in the same part of the sky
relative to their local horizon. Normally Pluto is considered the most
distant world in the solar system, but during the period from January 1979
until February 1999 it was actually closer to the Sun than Neptune. It has
the most eccentric and inclined orbit of any of the major planets. This
orbit won't bring Pluto back to its discovery position until the year
2178! Pluto is in a 2:3 resonance with Neptune; that is, it orbits the Sun
twice in the time it takes Neptune to orbit three times. It is the largest
of a family of objects called "Plutinos", objects about the size of Charon
and smaller, which also have a 2:3 resonance with Neptune. Plutinos are
one of several classes of minor planets that make up the Kuiper Belt, a
region just beyond the orbit of Pluto thought to be a source of periodic
comets. A current plot of these objects shows their relationship to Pluto
and other transneptunian objects in the outer solar system.
http://www.spacedaily.com/news/outerplanets-03g.html
SUMMER OUTREACH FOR THE FOREST SERVICE
We have arranged with the Forest Service to have four activities during
the summer season. On July 26 and August 23 we will present programs and
telescope viewing at the Black Rock ranger station. On August 2 and
August 23 we will make our presentations at the Tillie Creek Campground
amphitheater. Black Rock has a really dark sky, and Tillie Creek has a
really appreciative audience. Contact Carroll Evans for more info.
HAPPENINGS AT LOWELL OBSERVATORY
On June 5 to 8 Lowell Observatory had its first star party. Telescopic
viewing plus lectures on the grounds and field trips. CLAS member Rich
Burdge was one of the nearly 150 attendees.
MEMBERSHIP INFORMATION!
Basic CLAS dues are $20.00 per year, which includes the Skywatchers
Newsletter. As a benefit of membership you may also receive Astronomy
Magazine and/or Sky and Telescope Magazine. The fee schedule is as
follows:
Basic membership $20.00 per year
Membership with Astronomy magazine $44.00 per year
Membership with Sky and Telescope magazine $50.00 per year
Membership with both S & T and Astronomy $74.00 per year
Send your check to: Carroll Evans, Treasurer, China Lake Astronomical
Society, P.O. Box 1783, Ridgecrest, CA 93556.
PRESIDENT - Roger Brower - 760-375-1181 (email brower@iwvisp.com)
VICE-PRESIDENT - Bruce Churchill - 760-375-7247 (email
bchurchill@atsecure.net)
SECRETARY--TREASURER - Carroll Evans (email clevans@ridgenet.net)
NEWSLETTER EDITOR - Carroll Evans Jr. - 760-375-5681 (email
clevans@ridgenet.net)
WESTERN AMATEUR ASTRONOMERS WEB SITE
Meetings of the China Lake Astronomical Society are held at the Maturango
Museum at 7:30 p.m. on the first Monday evening of each month, except when
the first Monday is a holiday.
SKYWATCHERS
Newsletter of the
CHINA LAKE ASTRONOMICAL SOCIETY
POST OFFICE BOX 1783
RIDGECREST, CA 93556-1783
NEXT MEETING: 7:30 p.m., MONDAY, July 7, 2003 - "GARY PETERSON -
PLANETARY GEOLOGIST"
AT THE MATURANGO MUSEUM, 100 EAST LAS FLORES AVE.
CLAS WEB PAGE