The Antikythera Mechanism (photo right)

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                                                                                                              Volume 83
                                                                                                              Number 12
                                                                                                              October 2007

October 2007 talks:
The Antikythera Mechanism (photo right)
Saturday, October 27, 2007, 7:30 pm
Speaker: Dr. Tom Malzbender, of Hewlett-
Chabot Space & Science Center
Physics Lab, 2nd Floor, Spees Building

       n 1900 sponge divers off an island in Greece were seek-
       ing refuge from a storm when they stumbled across a
       magnificent ancient shipwreck. Among the wealth of
       bronze and marble statues recovered from the wreck
was a lump of clay and mud that failed to attract much atten-
tion. Eventually it was noticed that this lump had many
bronze gears embedded in it. This lump is now known as the
Antikythera Mechanism, an astronomical computer built by
the ancient Greeks around 140 BCE. It is believed to have
predicted the location of at least the sun and moon in the sky,     It’s that time of the year,
as well as lunar and solar eclipses. Nothing of comparable          again…
complexity is known to be fabricated by man for another 1000
years. Recently we applied our technique of reflectance imag-       EAS
ing to the surface of the mechanism, to assist in the process of
reading inscriptions and seeing surface detail. This simple
technique involves photographing the object under varying           Renewal Time
lighting conditions, but from a fixed perspective. From these
images, per-pixel estimates of surface normals can be made,         October 31st
which can be used to relight the object with improved reflec-
tance characteristics. More info and a demo is available at:        marks the end of the Eastbay Astronomical Soci-           ety membership year. Thank you for being with
index.html                                                          us in 2007! We hope you will consider rejoining
   Tom Malzbender is a senior research scientist at Hewlett-
Packard Laboratories and member of the Antikythera Mecha-
                                                                    us for 2008, and beyond!!! (Application Form inside)
nism Research Project. His research interest lie at the intersec-    DINNER WITH THE              Inside This Issue:
tion of computer graphics, signal processing and computer                  SPEAKER
vision. He has developed the methods of fourier volume ren-                 5:30 pm
                            dering, polynomial texture map-           Saturday, October 27        Catch some (lunar) rays  2
                            ping, reflectance imaging and opac-         HUNAN YUAN                Future conjunctions      2
                            ity-weighted volume resampling.         4100 Redwood Rd., #11         News ‘n Views            3
                                                                       (next to Safeway)          EAS Board minutes        3
                                                                            Oakland               CalStar star party       4
                            Tom_Malzbender/?                                                      Spare Shots              5
                            jumpid=reg_R1002_USEN                        (510) 531-1415
                                                                    No need to confirm—just       Directions & Schedule    6
                            «                                                                     EAS Membership form (insert)
                                                                            show up!
                                                                  Hesiodus is a crater
Catch Some (Lunar) Rays                                           28 miles in diameter
By Jane Houston Jones                                             to the east of Pitatus,
                                                                  with a pass into the

           unar sunrise and sunset rays are shafts of light       latter and with gaps
           which shine through clefts in crater walls and         in its north wall. Pi-
           mountains to illuminate the lunar surface. They        tatus is a magnificent
           occur only at very low angles of light - during lunar  lagoon-like ring, 50
sunrise or sunset. Sunrise and sunset rays are usually triangu-   miles in diameter, on
                                               lar-shaped illumi- the southern shore of
                                               nations. Don’t con-Mare Nubium. The
                                               fuse them with im- light of the rising
                                               pact crater rays –                           Sketch of the ray by the author, Jane
                                                                  Sun shines westward Houston Jones
                                               which are the de-  through the two cra-
                                               bris blasted out byters’ common gap and bisects Hesiodus. Two weeks later, the
                                               crater forming im- eastward shining light of the setting Sun bisects Pitatus. Sev-
                                               pacts on Coperni-  eral times a year the geometry of Earth, Sun and Moon allow
                                               cus and other      the light path to pass exactly through the low spot creating
                                               young craters. One the ray.
                                               of these rays, the    On October 19, 2007 I had mostly been showing people
                                               Hesiodus Sunrise   the Straight Wall, Plato, Cassini and Mons Huygens during
                                               Ray, is a favorite our monthly sidewalk astronomy night. My eye drifted from
                                               of mine. It’s easy the Straight Wall to Pitatus and Hesiodus. The center of Pi-
                                               to find the crater,tatus was bathed in sunlight, which cast a shadow on its cen-
                                               which is just southtral peak. The crater floor looked convex or dome-like to me.
                                               of Rupes Recta, or And guess what, the Hesiodus Ray, a narrow triangular shaft
                                               the Straight Wall. of light, illuminated the dark floor of Hesiodus.
                                                  Lunar ray spot-    You’ll find predictions for about 75 rays, including the
                                               ting gained popu-  Hesiodus and Pitatus Rays, on the Robinson Lunar Observa-
Hesiodus Ray Robin Casady Image of the         larity about 10    tory webpage,
hesiodus ray taken by Robin Casady             years ago thanks torays.htm. There are six opportunities to see each of these two
                                               an article about the
                                                                  fleeting shafts of light next year. The first dates are January
Hesiodus light ray in the July 1996 issue of Sky & Telescope.     16 and 31.
A cleft in the neighboring crater Pitatus provides an opening        Now get out and catch some rays! «
for the shaft of light to cross the floor of this crater at various
times throughout the year. Since that time, many amateur                     FUTURE CONJUNCTIONS—2007
astronomers have calculated when the sunrise or sunset will
strike a crumpled or broken crater wall and create these short- (We’re running out of year, so this list isn’t long.)
lived light shows.
                                                                  Oct 27 General Meeting, Chabot, Physics Lab, 7:30pm
                                                                  Nov 1 New EAS Membership year begins!
                                                                          (Have you renewed, yet?)
                                                                       15 Board Meeting, Chabot, Soda Board Rm, 7:30pm
                                                                       24 General Meeting, Chabot, Physics Lab, 7:30pm
                                                                    (tba) MOVN @ Chabot, Wightman Plaza*
                                                                  Dec 13 Board Meeting, Chabot, Soda Board Rm, 7:30pm
                                                                    (tba) MOVN @ Chabot, Wightman Plaza*
                                                                    (tba) Club Holiday Party (might be in the first part of January,

                                                                  *Members Only View Night:

                                                                  Always call 510 482-2913 after 5pm to confirm

                                                                  NOTE: Dates and times may change. We will provide as much
    Hesiodus - Map of the area from "The Moon", by Moore                advance warning as possible.
    and Wilkins (Faber & Faber, 1955)

                           Editor’s                                 EAS Board Meeting
                           News ‘n Views                            Thursday, September 13, 2007
                           Howdy astro fans! Hey! Pretty ex-        Attendees: Celeste Burrows, Alan Fisher, Terry Galloway,
                           citing speaker we’ve got this            Paul Hoy, Gerald McKeegan, Carter Roberts, Dave Rodri-
                           month, eh what? Can you imagine:         gues (via telephone), Don Saito, Paul Zurakowski.
                           an ancient Greek mechanical astro-
                           nomical calculator that pre-dates        Event Director’s Report: This month’s meeting will be an-
                           the birth of Christ? How would           nual Members’ Night. Will feature photos of Yosemite Star
                           such a thing work? What does it          Party and astrophotos from Barcroft. Also show Jane Hous-
do? Are they selling them on Ebay, yet? (I’m only half-             ton Jones’ monthly NASA web video. Speakers already
joking, here. I think it would be the ultimate in cool if some-     lined-up for October (Dr. Tom Malzbender of H.P. will be
day someone came up with a working replica of this thing.           speaking about the Antikythera mechanism, the 2,000 year-
Just think what a great conversation piece it would make!)          old Greek Astronomical computer), and November meetings.
                                            Debbie Dyke, Con-       Needs info on meeting dates for 2008; Sunday, March 23 or
                                        rad Jung, and I attended    30 for annual awards dinner? Or, Sunday Feb 24. Meeting
                                        this year’s AANC’s          dates for 2008: Jan 19, Mar 29, Apr 19, May 17, Jun 14, Jul
                                        2007 Reach for the          19, Aug 16, Sep 20, Oct 18 Nov 15.
                                        Stars convention, held      Treasurer’s Report: Invested spare club funds into short-term
                                        on Saturday, September      CD; will make about $35-$40 a month interest. Insurance for
                                        29, and it was a great      the next year has been paid. Spoke a little off-topic about
                                        success, with high at-      Nellie’s focuser. Sky & Tel can be renewed online without
                                        tendance, amazing           going thru the club.
                                        speakers, and tons of       Loaner Scope Program: Got a whole box of eyepieces (exact
Sam from Scope City handing out raffle
                                        fun for all participants.   number undetermined). Ray Wong told Paul he doesn’t want
                                        Highlights included         to be the lead for the program, but will be willing to help it.
(but were not limited to):                                          The Board will need to find someone else to take the lead on
• Dr. Imke de Pater, Professor of Astronomy and of Earth            this. Possibly involve the Galaxy Explorers to help fix up
     and Planetary Science at UC Berkeley, talking about the        some of the loaner scopes. Paul Z reports a woman contacted
     current studies on the rings of Uranus...                      him who wishes to donate a 12” reflector. Put a note in the
• Jane Houston Jones’ talk about NASA’s Cassini Space               newsletter asking for a volunteer to take over the LSP. EAS
     Probe Mission to Saturn...                                     to partner w/Chabot to use their and our loaners. Paul Z al-
• Christopher Go’s talk on high-resolution planetary asto-          most has a 24” scope that is ready to loan out. The Board
     photography, and Richard Crisp’s talk about emission           approved going ahead with the loaner program as it had been
     line astrophotography of deep sky objects...                   described in prior meetings (ie, a half dozen or more tele-
• A “Sky Tonight” planetarium show by Prof. Darryl Stan-            scopes maintained for loan to EAS members, also to other
     ford, using the College of San Mateo’s new Digistar 3          Chabot volunteers for use on the deck). The Board also de-
     planetarium...                                                 cided to seek an EAS member to help with the program.
• Thousands of dollars worth of raffle items, mostly from           Celeste offered to help by checking telescopes in and out
     Sam at Scope City...                                           during the times that she was at Chabot. We also decided to
• ...and many more activities, too numerous to list!                ask Ray if that would be enough assistance to allow him to
    The work on Chabot’s 36” reflector telescope Nellie con-        continue to head up the program.
tinues—tweaking, its alignment, prepping it for the addition        Regarding the Observing Program: The Board approved
of two 5” finder scopes, and for a set of ventilation fans to       supporting the four proposals that had been written up and
cool the mirror, faster, and break up the air over its surface      submitted in August, along with the subsequent edits. They
(which, surprisingly, has been shown to increase a mirror’s         are: the loaner program, the solar/daytime observing pro-
resolution). Slowly but Shirley, things do improve.                 gram, the observing pin program, and the scouts telescope
    The following is the September EAS Board Meeting Min-           training program at Chabot.
utes, to let you know the kind of stuff that we do at these         JPA Report: Terry reports things continue to go well between
meetings. There’s a bunch of stuff that goes on in our club         the EAS and CSSC under their new leadership. A motion
that doesn’t always get announced or discussed at the general       was made and passed to approve the EAS/CSSC Observing
club meetings, so I thought I’d start posting these so you can      Program (with a few small edits). Also:
see more of what we’re up to.
   And that’s it for now! «                                                                                     Continued Page 4

Meeting Minutes—Continued from Page 3

1. Several funding efforts underway with NASA and Moore Foundation.
2. Alex also has a number of other good funding leads he is exploring.
3. More interest now in starting planning for Deck expansion including solar telescope.
4. The combination of the above will help pay down the COPS loan, which will reduce Chabot large monthly interest pay-
ment burden.
5. Phase one of Blast Off - entering Space (formerly Living & Working In Space) is underway - this will not impact TMW.
6. Phase two will starting planning phase after Phase One is nearly completed and staff load lightens up.
7. Chabot has had many quarters of a pretty good budget balance condition and the future looks pretty stable but not high
    Outreach on the 13th of Oct. Motion for Board to recommend to Carter that he use his $500 Local Heros award to pur-
chase a 35mm Panoptic eyepiece for Nellie (recommended to him by Al Nagler, specifically for Nellie), and to use the rest of
the funds to purchase spare volunteer jackets for CSSC volunteer telescope operators. Terry G will donate a CG3 clock drive
to EAS; Paul H will donate a tripod to fit the CG3 to EAS; EAS to donate the working mount to CSSC, for use with their
Coronado PST, so EAS will get the credit for the donation. This will make it easier for daytime volunteers at Chabot to run
the PST for public (they won’t have to manually adjust it every few minutes). Volunteer operators of the system must be
trained on correct set-up and breakdown, storage of the equipment, otherwise, it will quickly become inop. Get flat cones for
the tripod feet, to help prevent accidental damage to the equipment.
New Night Sky Network: new kits coming, soon. Paul H has been reporting EAS’ attendance stats to NSN, which shows the
club’s activity level with the program, which is comparatively high. Channels 2 and 5 were here until 05:00 the morning of
the recent total lunar eclipse. Several EAS members were featured in short television news interviews.
    Carter to send Casey list of dates for 2008 EAS Board Meetings. «

                                                                   morning, despite the covers. But, all in all, it was a successful
Bill and Paul’s Excellent CalStar                                  one-night star party, and as you can see, they got some nice
Adventure                                                          results (see below). The Pleiades image was a total of 480
                                                                   secs at ASA 1000, and The Flame and Horsehead nebulae
CalStar, put on by the San Jose Astronomical Society, was          were 600 secs at 1000 ASA (next page) «
held this year on October 11-13 by the shores of the darksky
location Lake San Antonio, located over the hills west of
Hwy 101 between King City and Paso Robles. Dedicated                                                               |The Pleiades
astrophotographers and EAS members Paul Hoy and Bill                                                               open star clus-
                                                                                                                   ter, Messier
Drelling were itching to check out Paul's new Canon 40D                                                            catalog number
digital camera, get some practice with it, and see what it                                                         45. Paul’s
could do. Paul got there around 11:30am of the event’s last                                                        photo captures
day, but it was cloudy. He decided to hang out to see if it’d                                                      the glowing gas
be worth it for Bill to attend, too. The night before, they'd                                                      remnant of the
gotten 45 mins of viewing between rain showers. Paul and                                                           cluster’s forma-
Bill thought about going to Henry Coe State Park instead, but                                                      tion cloud.
Bill wanted to see the CalStar location, so he decided to
come down, even if only to see the site and talk to the people,
there. Plus, the weather was looking a bit more favorable.
   Bill arrived around 5pm, and they had a catered dinner                                                          |The far-left
with tri-tip steak; there was no entry fee to the event, but the                                                   star in Orion’s
Park charges $20 per night, and of course they had to pay for                                                      Belt, Al Nitak,
the meal.                                                                                                          lights up the
   The weather improved enough to take pictures, so they set                                                       Flame and
up, and began imaging. It was mostly clear, but around 2am                                                         Horseshoe
fog started coming in and the dew started falling. They went                                                       nebulae, and
until 3:30am, took their last picture of Al Nitak in the Belt of                                                   glows with extra
Orion (looked like a huge star, due to the effects of the                                                          substance due
clouds overhead). Paul had no sooner got nestled down to                                                           to dew forming
                                                                                                                   on the lens dur-
take a nap when Bill knocked on the window to say a dense                                                          ing the session.
fog was moving in, so he had to get up again to cover his
gear. It was so bad, their equipment was still dripping in the

Spare Shots
                | Ken Swagerty caught
                this amazing photo of a
                Blue Angel F/A 18 going
                trans-sonic, causing a
                shock-induced vapor
                cloud to form
                }Peter Jenniskens (of
                meteor shower predic-
                tion fame) and EAS
                member Debbie Dyke at
                AANC’s AstroCon 2007

                              }No, it’s not
}The                          the revival
College                       of disco.
of San                        Don Saito
Mateo’s                       points out
new                           Venus at the
planetar-                     Boy Scout
ium,                          Expo, held
where                         at Memorial
many of                       Park in Al-
AstroCon                      bany. Photo
2007                          by Gerald
events                        McKeegan
were held

                  |Lying down on
                  the job. Conrad              |Paul Terrill
                  Jung was getting             shows Japanese
                  a sore neck doing            Moon Viewing
                  critical mirror              Festival Coordi-
                  alignment adjust-            nator Liane Scott
                  ments on Nellie,             the Moon through
                  so Ken Swagerty              his Orion 4.7”
                  put a bench onto             refractor.
                  the hand operated
                  fork lift and made
                  the job a little
                  easier for him.

}Paul Hoy                 }Gerald
shows atten-              McKeegan shows
dees at the               M15 to Moon Fes-
Japanese                  tival attendees,
Moon Festi-               held at Lake Mer-
val where his             ritt’sGarden Cen-
telescope is              ter. Not bad, from
pointed on a
                          the middle of the
                          City of Oakland!

                          And that’s it for
                          now! «

     Post Office Box 18635 = Oakland, CA 94619-0635
                        October 2007

Eastbay Astronomical Society
President:    Carter Roberts (510) 524-2146          Vice President:    Paul Hoy         (510) 531-6305
Treas:        G.McKeegan        (925) 926-0853        Membership Reg: Bruce Skelly
Secretary:    Linda Lazzaretti (510) 633-2488                                        Events Coord:      Dave Rodrigues (510) 483-9191
Articles and photos for The Refractor are encouraged. Deadline for the November 2007 issue is November 3, 2007. Items may be submitted by mail to:
Editor - 3514 Randolph Avenue, Oakland, CA 94602-1228. Internet email address: Hm: (510) 482-2913.

                                                                                                      Join the Eastbay Astronomical Society
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                                                                                                      Discounted Magazine Subscriptions:
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                                                                                                      October 31. New memberships starting from July - October will be
                                                                                                      good through to the end of October of the next year
                                                                                                      Contact: EAS Treasurer
                                                                                                      Post Office Box 18635
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                                                                                                      Telephone: (925) 926-0853
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Optional discounted 12-month magazine subscriptions:
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Please mail this form and your check or money order payable to:
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PO Box 18635
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For more information, please contact Membership Registrar Bruce Skelly at, or the address,

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                             Membership has its privileges…
                   = Monthly newsletter, The Refractor, with interesting articles on currently visible
                   constellations, upcoming lectures, club events, stories, equipment reviews, local news,
                   and more.
                   = Monthly meetings with featured guest speakers on all subjects from Astronauts to
                   Zooming telescope eyepieces; from finding deep-sky objects, to planetary geology.
                   Every and any thing having to do with astronomy, telescopes, and the space sciences.
                   All that, and cookies and sodas, too!
                   = Help and advice to new telescope owners. Got a new telescope and don’t know
                   what to do with it? Bring it to a meeting; we’ll be able to help you figure it out! If
                   you’re interested in getting a telescope, we can give you some good advice; be warned:
                   there are a lot of bad telescopes out there!
                   = Members-Only view nights at Chabot’s large telescopes to avoid the weekend
                   crowds. We view galaxies, nebulae, star clusters, planets, the Moon, comets, double-
                   stars, and whatever else is up!
                   = Weekly star parties at Chabot. Interested EAS members get trained to operate the
                   big ‘scopes (Leah, Rachel, and Nellie, the 8”, 20”, and 36” telescopes housed in three
                   separate observatories) for Friday and Saturday night public viewing.
                   = Yearly events: Annual EAS Awards Dinner, star parties at nearby dark-sky sites,
                   the Barcroft Station high-altitude star party in the White Mtns.
                   = Telescope Makers’ Workshop. Friday evenings from 7–10 pm, hosted by Chabot,
                   and operated by the EAS. For a small fee, plus the cost of the mirror and “tool,” we
                   will provide instruction and grinding/polishing supplies needed to make your own tele-
                   scope mirror for less than half the cost of a store-bought one, that will likely be opti-
                   cally superior!
                   = Advanced Astro-research Groups using Chabot's large telescopes. Join a group to
                   fit your particular astro-interest such as CCD or Film Astrophotography, Variable
                   Stars, Solar, Seismological, Extra-Solar Planets, Occultations, Optical SETI, and more.
                   Access to Chabot’s Science Library
                   Automatic membership in the
                   Astronomical League (a $16 value)
                   Astronomy and/or Sky & Telescope subscription discounts (a $10 value)

                   + Discounts on many items in the Sky and Telescope merchandise catalog

Join the Eastbay Astronomical Society, and begin expanding your knowledge of, and appreciation for, the
                                night sky, our world, and the Universe!