CONTENTS San Diego Astronomy Association Celebrating Over 40 Years of Astronomical Outreach Office (619) 645-8940 Observatory (619) 766-9118 http://www.sdaa.org A Non-Profit Educational Association P.O. Box 23215, San Diego, CA 92193-3215 October 2004 SDAA Business Meeting Next meeting will be held at: SKF Condition Monitoring 5271 Viewridge Court San Diego, CA 92123 October 12 at 7:00pm Changes to the TDS Site Rules by Scott Baker Vice President In the past few months two rules have either been modified or added to the "Rules for the Tierra Del Sol Observing Site" document. The most recent change, made at the September Business Meeting was to rule four (4.) which now reads. "4. Members and guests shall use only the minimum light necessary for safety, and light should be red or masked in red to preserve night vision. Lights shall be kept pointing towards the ground whenever possible. The use of laser pointers is prohibited at all times. Laptop computers should use a red filter and be masked or shielded so that no stray light escapes the sides of the display. Check and be sure it is clear to use lights before proceeding in or out of any area. Be considerate of others and their night vision and photography efforts." (continued page 5) Clean Up TDS & Bar-b-que! Jerry Hilburn, The Trash Guy! Ladies and Gentlemen its time to break out the shovels and rakes, wheel the barrels and get busy cleaning. On October 9th and October 16th we will be cleaning up TDS. The fun starts at 10AM on both days and the goal is to get as many pieces of junk off the property as possible, do some scraping and painting, and clean the warming room and storage containers. We will be leasing a 40ft trash container to haul away the junk and we need your help. If you can come out and pitch in we plan to feed you at the close of each days work (~ 4pm). So we are planning a bar-b-que for the workers that come to help! We need you to volunteer. In order to plan the meal please send a confirmation to Jerry Hilburn at: [email protected] or call (858) 565-4059. Program Meeting October 20th Rich Strobel, SDAA Star Party Chair November 17th Annual Board Nominations Mission Trails Regional Park Visitor and Interpretive Center 1 Father Junipero Serra Trail October 2004 Vol XL, Issue 10 Published Monthly by the San Diego Astronomy Association 75¢ /$8.00 year Incorporated in California in 1963 TDS Site Rules .............................................1 Astronomy 101............................................2 Treasurer’s Report.......................................5 Program Meeting .........................................5 Sky Watch.....................................................6 AISIG Update..............................................7 Board Meeting Minutes..............................8 Space Technology ......................................10 Border Lights...........................................11 The Back Page...........................................12
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CONTENTS
San DiegoAstronomy AssociationCelebrating Over 40 Years of Astronomical Outreach
Office (619) 645-8940Observatory (619) 766-9118http://www.sdaa.orgA Non-Profit Educational AssociationP.O. Box 23215, San Diego, CA 92193-3215
October 2004
SDAA Business MeetingNext meeting will be held at:SKF Condition Monitoring
5271 Viewridge CourtSan Diego, CA 92123October 12 at 7:00pm
Changes to the TDS Site Rules
by Scott Baker
Vice President
In the past few months two rules have either been modified or added
to the "Rules for the Tierra Del Sol Observing Site" document. The
most recent change, made at the September Business Meeting was to
rule four (4.) which now reads.
"4. Members and guests shall use only the minimum light necessary
for safety, and light should be red or masked in red to preserve night
vision. Lights shall be kept pointing towards the ground whenever
possible. The use of laser pointers is prohibited at all times. Laptop
computers should use a red filter and be masked or shielded so that no
stray light escapes the sides of the display. Check and be sure it is clear
to use lights before proceeding in or out of any area. Be considerate
of others and their night vision and photography efforts."(continued page 5)
Clean Up TDS & Bar-b-que!Jerry Hilburn, The Trash Guy!
Ladies and Gentlemen its time to break out the shovels and rakes,
wheel the barrels and get busy cleaning. On October 9th and October
16th we will be cleaning up TDS. The fun starts at 10AM on both days
and the goal is to get as many pieces of junk off the property as
possible, do some scraping and painting, and clean the warming room
and storage containers. We will be leasing a 40ft trash container to
haul away the junk and we need your help.
If you can come out and pitch in we plan to feed you at the close of
each days work (~ 4pm). So we are planning a bar-b-que for the
workers that come to help! We need you to volunteer. In order to
plan the meal please send a confirmation to Jerry Hilburn at:
Sun., 3 Oct. —— VENUS is less than a half degree from REGULUS before dawn this morning(see below).
Sat., 9 Oct. —— PUBLIC STAR PARTY @ Tierra del Sol. There will be a work party during thedaytime to clean up the site at TdeS & a bar-b-q for those who do work (no free lunch!).
Wed. 13 Oct. —— NEW MOON, 7:48 p.m.; a PARTIAL SOLAR ECLIPSE is visible today if you’rein Hawaii, Alaska or Japan (where it will be the 14th!).
Sat. Oct. 16 —— “New Moon Night.”Sat., 23 Oct. —— PUBLIC STAR PARTY @ Tierra del Sol; explore the Moon’s “terminator”
(where dark turns to light) for spectacular views of mountains, craters & rills.Wed., 27 Oct. —— FULL MOON, 8:08 p.m.
—— TOTAL ECLIPSE OF THE MOON; totality begins 7:23 p.m. & ends at 8:45p.m., partial ends at 9:54 p.m. & penumbral ends at 11:03 p.m. This is the last totaleclipse of the moon visible anywhere in the world ‘til 2007 so don’t miss it!
Note that the penumbral phase of the eclipse will already have begun before themoon rises. Specifically, sunset is at 6:02 & moonrise is a few minutes earlier at 5:54. The partial phase of the eclipsebegins at 6:14 so you should be able to spot it ifyou have a clear view of the eastern horizon.
Another factor is twilight. The USNO (U.S. Naval Observatory) defines “civil twilight” as the sun being 6degrees below the horizon with terrain & horizon still visible (6:27 on the 27th). “Nautical twilight” is the sun 12degrees below a now hardly visible horizon (6:56 on the 27th) & “astronomical twilight” is the sun 18 degrees belowthe horizon with darkness complete (7:25 on the 27th). Thus, the startling & lovely contrast between the silvery fullmoon & the pumpkin-colored fully eclipsed moon will not be as dramatic for us here in San Diego at the beginningof the eclipse as it will at the end. So sit it out!
Sun., 31 Oct. —— Daylight Savings Time ends; move clocks back an hour this morning. —— HAPPY HALLOWEEN tonight!
EVENING PLANETS:There are no naked eye planets visible in the evening. {Boo! Hiss!} However, NEPTUNE [ ** ] in Capricornus the
Goat & URANUS [ * 1/2 ] in Aquarius the Water Carrier are now visible fairly high in the sky. They require telescopes toresolve their discs, but you sharp-eyed younger viewers can spot Uranus naked eye if you have a good finder chart. {I used tobe able to myself!}
MORNING PLANETS:SATURN [ * ] is in Gemini the Twins & is high in the sky before dawn. VENUS [ * ] crosses from Leo the Lion (see
above for its close pass of Regulus on the 3rd) into Virgo the Virgin. JUPITER [ * ] is also in Virgo & daily (nightly!) getshigher in the sky, & thus more available for telescopic viewing, as the month goes on. Jupiter & Venus will pass each othernext month. Late in the month, MARS [ * 1/2 ], likewise in Virgo (I wonder what astrologers make of all this planetaryactivity in Virgo!), can be spotted low on the horizon next to Spica shortly before dawn breaks, providing a nice white contrastwith ruddy Mars.
San Diego Astronomy Association
Page 7SAN DIEGO ASTRONOMY ASSOCIATION NEWS AND NOTES, OCTOBER 2004
{ N.B. Because of the recent discoveryof 2 relatively large trans-Neptunianobjects, many professional astronomersno long consider Pluto a planet. I’ll goalong with them! }
TIERRA DEL SOL LAT = 32º 36' 48" N ( ±0.l” ), LONG = 116º 19' 55" W( ± 0.1" ), ELEV = 3710'( ± 5' ), at the bathroom, asdetermined from USGS 7.5min 1/24000 map.
Send comments & questions tome by phone (619/225-9639),USPS (4538 Long Branch Av.,San Diego, CA 92107) or mye-mail address([email protected]).
¡HAPPY VIEWING!
AISIG UPDATEby Jerry Hilburn, AISIG Chair
The October AISIG meeting will be held at 4 PM in the warming room at TDS on October
16. We are hoping to have a Meade DSI available for that meeting and will have a follow on
demonstration at Observatory 7 between 9 and midnight. With the installation of the fire
suppression tank and the recent work completed on critical infrastructure the time has come
for the AISIG group to restart the AISIG imaging area project. We need a big turn out to get
this project going. We will be reviewing site plans and selecting a layout for the new area at this
meeting. Please plan to attend the meeting on the 16th.
The AISIG site is off to a great start and we now have over 120 images for the public to view
at http://aisig.sdaa.org. If you have not visited the site please take a few minutes to go look. I
am sure you will be amazed at the work the AISIG group has posted. If you haven't signed up
to post pictures, there is no time like the present to get going. My goal for AISIG is to have
over 5000 pictures online by the close of 2005. The AISIG site is unique and I have yet to find
anything quite like it among the other club sites that I have visited on the Internet. So far since
the site opened we have had over 2000 unique visitors. Lets get busy posting!
OPT and Mike Fowler for selling
us the monthly prizes at their
cost.
The October meeting, on the
20th, will feature our own Rich
Strobel, who has put together a
presentation on our public out-
reach star parties. So make sure
you attend and see some of the
great photos of people and
members enjoying our star party
program and learn how you too
can help this great cause.
The monthly program meetings
are held at the Mission Trails
Regional Park Visitor Center
Program continued from page 4 Theater on the third Wednesday
Page 10 SAN DIEGO ASTRONOMY ASSOCIATION NEWS AND NOTES, OCTOBER 2004
Hunting Gravitational
Waves: Space
Technology 7
by Patrick L. Barry and Dr.
Tony Phillips
Among the mind-blowing impli-
cations of Einstein’s general
theory of relativity, direct verifica-
tion is still missing for at least
one: gravitational waves. When
massive objects like black holes
move, they ought to create distor-
tions in space-time, and these
distortions should spread and
propagate as waves—waves in the
fabric of space-time itself.
If these waves do exist, they
would offer astronomers a pen-
etrating view of events such as
the birth of the Universe and the
spiraling collisions of giant black
holes. The trick is building a
gravitational wave detector, and
that’s not easy.
Ironically, the gravitational waves
spawned by these exceedingly
violent events are vanishingly
feeble. Gravitational waves exert a
varying tug on objects, but this
tug is so weak that detecting it
requires a device of extraordinary
sensitivity and a way to shield that
device from all other disturbances.
Enter Space Technology 7 (ST-7).
This mission, a partnership
between NASA’s New Millennium
Program and the European Space
Agency (ESA), will place a satel-
lite into a special orbit around the
Sun where the pull of the Earth’s
and Sun’s gravities balance. But
even the minute outside forces
that remain — such as pressure
from sunlight — could interfere
with a search for gravitational
waves.
DRS works by letting two small (4
cm) cubes float freely in the belly
of the satellite. The satellite itself
shields the cubes from outside
forces, so the cubes will naturally
follow an undisturbed orbit. The
satellite can then adjust its own
flight path to match that of the
To make the satellite virtually
disturbance-free, ST-7 will test an
experimental technology that
counteracts outside forces. This
system, called the Disturbance
Reduction System (DRS), is so
exquisitely sensitive that it can
maintain the satellite’s path within
about a nanometer (millionth of a
millimeter) of an undisturbed
elliptical orbit.
cubes using high-precision ion
thrusters. Making the masses
cube-shaped lets DRS sense
deviations in all 6 directions (3
linear, 3 angular).
ST-7 is scheduled to fly in 2008,
but it’s a test mission; it won’t
search for gravitational waves.
That final goal will be achieved by
the NASA/ESA LISA mission(continued page 12)
San Diego Astronomy Association
Page 11SAN DIEGO ASTRONOMY ASSOCIATION NEWS AND NOTES, OCTOBER 2004
Tierra del Sol Border Light
Status Reportby Craig Ewing
The lights being placed along the
border near the SDAA's Tierra del
Sol observing site are a concern
to all who use the site. On June
19th, I decided to research it to
find out first hand what is the
situation. That day, Don Spencer
and I drove along the border
fence. Our discoveries were
"enlightening".
We found five "devices", each
with 4 lights attached to the top
of them. (Refer to Boarder Light
A and Boarder Light B.) Each
device was separated by 1/4 mile.
Even though they were located
south-southeast of the SDAA
observing site on June 19th
(Boarder Light C), each device has
wheels and, as such, can be
moved to a different location
relatively quickly. During future
star parties, members may notice
the lights coming from a slightly
different direction.
One interesting thing to note is
that the lights were located along
the top of a ridge that day. If I
remember correctly, I'd heard that
the border patrol said that they
were going to install the lights in a
ravine near the border because
illegal immigrants could more
successfully evade them when
passing through it as opposed to
crossing the border along the
surrounding ridges. The ravine is
approximately 2 miles wide. On
the other hand, I'd heard SDAA
members say that the border
patrol plans on installing enough
lights to cover a 5-mile stretch of
border. If that happens, then the
lights will be able to light up both
the ravine and the surrounding
ridges.
Boarder Light A
Boarder Light B
Boarder Light D
Most of the devices were ar-
ranged so that two of the lights
were pointed down onto the
fence and the other two lights
were pointed out over the fence.
However, the central device had
two lights pointed directly east
and two lights directly west.
(Refer to Boarder Light D.) This
will probably create more light
scattering. Regarding light scatter-
ing, during the night of June 19th,
we noticed increased light pollu-
tion when the moisture in the air
increased. This could be signifi-
cant if and when more lights are
installed.
I hope that this information is
useful to people who are inter-
ested in learning about the border
light situation near Tierra del Sol.
For those of you with Internet
access, I uploaded additional
photographs of our experience in
the "Photos, Border Lights 2"
folder at the SDAA Yahoo! Chat
Group Web page-- http://
groups.yahoo.com/group/
SDAA/.
Boarder Light C
THE BACK PAGE
(Laser Interferometer Space
Antenna), which is expected to
launch in 2011. LISA will use the
DRS technology tested by ST-7 to
create the ultra-stable satellite
platforms it needs to successfully
detect gravitational waves.
If ST-7 and LISA succeed, they’ll
confirm Einstein (again) and
delight astronomers with a new
tool for exploring the Universe.
Read more about ST-7 at http://
nmp.jpl.nasa.gov/st7 . For kids in
a classroom setting, check out the
“Dampen that Drift!” article at
http://spaceplace.nasa.gov/en/
educators/teachers_page2.shtml .
This article was provided by the JetPropulsion Laboratory, CaliforniaInstitute of Technology, under a contractwith the National Aeronautics andSpace Administration.