WADHURST ASTRONOMICAL SOCIETY

FEBRUARY NEWSLETTER 2008

INDEX: MEETINGS, OTHER NEWS, CONTACTS

MEETINGS

JANUARY MEETING

ANNUAL GENERAL MEETING

John Vale-Taylor chaired this year's Society Annual General Meeting, held prior to the January talk and he began by saying that the Society was healthy and had a current membership of over forty members.

He recalled some of the Society's activities over the past year.  Once again, thanks to Michael and Claire Harte, we had another enjoyable barbecue with good skies, enabling members to spend some time appreciating the summer constellations and the Milky Way.  The Moon proved an interesting object low in the southern sky.

Many members came on a visit to Belmont House near Faversham to be shown round the largest private collection of clocks in the British Isles.  John told the meeting that the visit had been generously organized by one of our own members who had also arranged for John Betts from Greenwich to be our guide.

The Chairman invited Mike Wyles, our Treasurer, to give a summary of the Society's accounts.

Mike said that, despite the Society purchasing a new 35mm carousel projector and a digital projector, funds remained stable mainly helped by the change of venue for our meetings and the subsequent reduction in the cost of hiring a room.

The Society's accounts stand at:

Current Account £349.51

Reserve Account £1,140.16

The members passed the accounts for submission to the Accountant.

Phil Berry talked about the speakers he had arranged over the past year and it was unanimously agreed that they had been a success.  He then talked about talks already arranged for this year, a list of which appears elsewhere in this Newsletter.

Members may remember the talk by Gilbert Satterthwaite on the Great Transit Circle at Greenwich Observatory.  He was the last observer to take official readings back in the 50s.  Phil told the meeting that Gilbert was very willing to take a group on a weekday tour of the Circle, which could also be combined with a visit to the new planetarium.  A weekday was necessary because of the crowds at a weekend.  At present, Phil hasn't been able to contact him so far this year, but it is hoped to arrange this visit for some time during the first three weeks of June this year.  Details will follow.

Looking further into the future, Phil said that a visit to see the Time Galleries at the Maritime Museum in Greenwich with Jonathan Betts, Curator of Horology, has been arranged for Saturday 21st of March 2009.  Again more information about this nearer the time

The Newsletter Editor had an embarrassing occurrence to relate.  A certain unfortunate accident with the laptop resulted in a loss of email addresses.  They have now been recovered but some omissions or errors may still occur.  He would like to hear about any.

The Strasbourg Astronomical Clock

Talk to the January meeting by Phil Berry

Phil began by introducing us to the beautiful city of Strasbourg and touching on its history and development as the seat for several European institutions such as the Council of Europe, the European Parliament and the European Court of Human Rights.

Towering over the historical centre is the 142 metre tall Notre Dame Cathedral, the fourth highest church in the world, in which Phil found the particularly impressive Strasbourg Astronomical Clock.

There were two earlier clocks in the cathedral, the first being built in 1352 and called the "Three Kings Clock" with a height of 12 metres.  This clock stopped early in the 16th century but sadly no drawings of it have ever been found.   It is known that at the bottom was a calendar, then an astrolabe and above this a statue of the Virgin and Child.

Every hour the Magi would bow whilst chimes played and a cock crowed and flapped its wings.

Starting in 1547 a new clock was started but construction was halted when the Cathedral was handed over to the Roman Catholics, to be resumed again in 1571 by two brothers.  This clock was much more ornate and astronomically complex.

The original automaton cock was used and still exists in the Strasbourg Museum of Decorative Art.

The 1547 clock also had panels, which had predictions of eclipses for the period 1613 to 1649 but had not been updated after 1649 and illustrate how the clock gradually fell into obsolescence.  Where those panels were, became the home to the most advanced mechanisms ever devised.  For example, a movement hidden inside a pelican powered the celestial globe.  The celestial globe showed 48 constellations and 1022 stars.

There was a Calendar Dial, painted for the century between 1670 and 1769.  Above this was a geocentric astrolabe representing the sky as seen above Strasbourg.

The iron gears and wheels finally wore out and clock stopped in 1788.

One day in 1788, the Cathedral's beadle, having shown some visitors around the motionless clock saying that no-one would ever be able to set it going again, a twelve-year old boy shouted that he would make it work and spent the rest of his life to acquiring the skills necessary for this work.  His name was Jean-Bapbtiste Schwilgué.

At the tender age of 61 he was at last entrusted with the work of renovating the clock.  According to a plaque, he carried out the work between 1838 and 1842, although the actual completion date was in fact 1843.

This is the 1547 clock, fully restored and rebuilt in and is as it can be seen today.

This clock is 18 metres high and on the left is the well-decorated weight turret in which 5 weights descend, giving power to the various areas of the clock.  The weights are wound up once a week.

To the right of the clock is an impressive spiral marble staircase, which gives access to the upper parts and the dials.

The central body also built from marble, displays the scientific data and automata and also contains much of the mechanism.

On top of the central body is a crown that is used to hold a set of chimes and on top of the crown is a tiny statue of architect Uhlberger who designed the staircase and central body of the clock.

At the junction of the base and central body is the clock that one looks at if they want to know the time.  However, there are two sets of hands.  The white hands show Official Time and the gold hands, the Local Time.  Local time is 30 minutes behind the official time and it is the local time that controls the automata.

As a result midday local time is at 12:30 official time!  It is therefore 12:30 when the visitor needs to be present to watch the major display.

Near the top of the central body, an old man strikes the 4 quarter hours before Death strikes the hours.

Phil said that during the major display, one needs to know just where to look to see the next action or it will be missed.  Following the chiming of the hours, the apostles process before Christ who blesses each one and then blesses the watching crowd.

The days of the week are indicated on the calendar and at the base of the central body is the apparent time dial. The year is indicated on a perpetual calendar together with the months, days and their saints.

The next part of the clock Phil described was the ecclesiastical computation showing the mechanism and the superb quality of workmanship.

The clock indicates our position in the solar cycle (a period of 28 years), and also shows the lunar cycle, or golden number (a period of 19 years).  It also calculates the dominical letters, the epact (number of days between last new moon and the first of January)

At the front is the Celestial Globe, which reproduces very accurately the movement of more than 5,000 stars and revolves in one sidereal day.  The clock even takes into account precession, the imperceptible movement of the poles in a circle taking 28, 806 years to complete!

Behind the Celestial Globe is the Apparent Time dial, which is set for the northern hemisphere.  It indicates such things as sunrise and sunset, eclipses and lunar and solar equations.

The planetary dial shows the six visible naked-eye planets.  The signs of the zodiac are shown around the rim.  In proportion to reality their size distances and movements are reproduced with a precision of one hundred millionth.

Phil showed a short video with sound of the very impressive clock in action and it certainly was impressive.

Phil ended his introduction to this incredible mechanism by advising that anyone wishing to see the clock in action needs to buy a 1€ ticket from one of the kiosks inside the cathedral selling pictures, then exit to re-enter the cathedral by the side door on the south transept steps at 1130 (official time).  You can purchase tickets through a small window by the steps from 1130 but the queues then can be very long.

FEBRUARY MEETING

Wednesday 20th February 2008 John Vale-Taylor will be talking to Tim Bance, an amateur astronomer with a mass of experience in astronomy and telescope building. - "The Tim Bance Interview".

The meeting begins at 1930 although members are invited to arrive anytime after 1900.  This is a good time to exchange ideas and discuss problems.

The venue as always is in the Upper Room of the Methodist Church at the east end of Wadhurst Lower High Street, opposite Uplands College.  (For those with SatNav -  Post code TN5 6AX)

FUTURE MEETINGS & EVENTS

Wednesday 19th March 2008 A welcome return of Konrad Malin-Smith with his talk "The Magellanic Clouds".  This takes us just outside our own galaxy to two of the Milky Way's closest neighbours in space.

Wednesday 16th April 2008 Greg Smye-Rumsby gives a talk he has entitled "Bits and Bobs".

Wednesday 21st May 2008 Our own Brian Mills who contributes the excellent Sky Notes each month is giving a talk about Occultations.

Wednesday 18th June 2008 Because this is one of the shortest nights of the year, in recent years we have made this a members evening when we can bring telescopes, binoculars and other aids to amateur astronomy and chat about their use and discuss problems.  There will also be a short video on an astronomical subject.  More info nearer June.

GO TO INDEX

  OTHER NEWS

SUBSCRIPTION FOR THE CURRENT YEAR

The new session of the Society began on January the first.  As Editor, I am guilty of not including a note about this in the last Newsletter.

The Treasurer, Mike Wyles, is ready to accept subscriptions, which are the same as previous years at £15 per member and £20 for two members in the same family.

Mike prefers to receive a cheque payable to "Wadhurst Astronomical Society" although he will take cash.  If it is more convenient, subscriptions can be sent direct to him at:

Mr. M Wyles, 31 Rowan Tree Road, Tunbridge Wells, Kent TN2 2UN.

FORMING A  "HANDS-ON" GROUP

During the January meeting, an interesting idea was put forward by Angus Macdonald inviting anyone wishing to form a group of members interested in the practical side of telescope making to get together at the February meeting or make their interests known through one of the Committee members.  Angus also said that he would willingly host the first meeting and suggests perhaps the 26th or 27th of February as a possibility, which is about a week after our February meeting.  This gives us a chance to talk about it at the meeting.

This is an exciting and positive proposal and one or two members already said how much they would welcome such a group.  Members interested would not necessarily need particular abilities but in this way they could learn and share new and useful skills.

AN OFFER TO OBSERVE AN OCCULTATION

An interesting offer is made by Brian Mills to form a group to observe a grazing occultation on the 14th of March.  He has more information at the end of his Sky Notes for February.

THE "HELP LIST"

At the monthly meetings, Phil Berry has introduced a clip-board with a sheet headed "Help List" intended for anyone asking advice.  It is being used successfully and members are reminded to use the list as much as possible.  It can be useful for discussion purposes as well as hopefully providing answers.

UK ASTRONOMY FUNDING CRISIS

Phil Berry has received the following email from John Axtell the Secretary to SAGAS (The Southern Area Group of Astronomical Societies):

You will no doubt have already seen emails about the threat to funding for astronomical research in the UK.  The following is from John Murrell, SAGAS webmaster.

"I have added a new page to the SAGAS web site about the funding crisis for UK astronomy with links to the E-Petition & the site that allows you to email your MP."

The SAGAS website is: www.sagas.org.uk/

ASTROFEST 2008

A reminder that this year's European AstroFest takes place at the Kensington conference & Events Centre, Kensington and Chelsea Town Hall, Hornton Street, W8 7NX, London on Friday the 8th and Saturday the 9th of February.  Doors open 0900 until 1800 each day. 

Apart from exhibitors there is also a programme of talks in the lecture theatre, but one would be advised to book those before they go.

Details at: www.astronomynow.com/astrofest

SKY NOTES FOR DECEMBER

Planets

Mercury is a morning object during February following its inferior conjunction on the 6th. It will be difficult to locate, rising only about an hour before the sun by the middle of the month. The best views of Mercury this year will be during the evening in May, and in the morning in October.

Venus is a morning object at magnitude -3.9 and is only visible low down in the south-east as it moves back towards the sun. It is only one degree away from Mercury on 26th February.

Mars is still an easy object in Taurus (the bull) but is moving eastwards back towards Gemini (the twins). By the 24th its magnitude will have decreased to 0.0 as we move further apart.

Jupiter is a morning object very low down in the south-east. By the middle of the month it will have a magnitude of -1.9 but rises only an hour before the sun. Venus is less than one degree away on February 1st.

Saturn lying in the constellation of Leo (the lion) at magnitude +0.3 rises at around 18.00 hrs by the middle of the month. It will be well placed for observation and will show the rings gradually becoming more edge on as the year progresses.

Lunar Occultations

      There is also an occultation of the magnitude 2.8 star Tau Scorpii on the morning of 29th February. Unfortunately the two events (a disappearance on the bright limb and reappearance on the dark limb) occur at 04.42 and 05.50 respectively.

Lunar Eclipse

In the early hours of February 21st there will be a total eclipse of the moon. The partial phase begins at 01.43 and ends at 05.09 whilst the total phase lasts from 03.00 until 03.51. During lunar eclipses it is common for the moon to appear reddish brown in colour. The degree of colouration is dependant upon the impurities in our atmosphere through which the suns rays are refracted on their way to the moon.

There are some occultations that occur during eclipse but unfortunately they are all of magnitude nine or lower. If you would like details please let me know.  Tel: 01732 832691

ISS

Below are details of the most favourable passes of the ISS this month. The information is only given for when it is at maximum altitude, so it is best to look a few minutes before this time. Full details of visibility can be found at:

Advance warning

Friday March 14th - Graze occultation of a magnitude 6 star in Gemini. The track for this passes just north of Borough Green, travels through Headcorn and Hamstreet and out into the Straits of Dover at St. Mary's Bay. If anyone is interested in making up a group to try and observe this then please feel free to contact me at:

brian@wkrcc.co.uk or  telephone 01732 832691.

Brian Mills

NASA SPACE PLACE

No Mars Rock Unturned

by Patrick L. Barry

Imagine someday taking a driving tour of the surface of Mars. You trail-blaze across a dusty valley floor, looking in amazement at the rocky, orange-brown hillsides and mountains all around. With each passing meter, you spy bizarre-looking rocks that no human has ever seen, and may never see again. Are they meteorites or bits of Martian crust?  They beg to be photographed.

But on this tour, you can't whip out your camera and take on-the-spot close-ups of an especially interesting-looking rock. You have to wait for orders from headquarters back on Earth, and those orders won't arrive until tomorrow. By then, you probably will have passed the rock by. How frustrating!

That's essentially the predicament of the Spirit and Opportunity rovers, which are currently in their fourth year of exploring Mars. Mission scientists must wait overnight for the day's data to download from the rovers, and the rovers can't take high-res pictures of interesting rocks without explicit instructions to do so.

However, artificial intelligence software developed at JPL could soon turn the rovers into more-autonomous shutterbugs.

This software, called Autonomous Exploration for Gathering Increased Science (AEGIS), would search for interesting or unusual rocks using the rovers' low-resolution, black-and-white navigational cameras. Then, without waiting for instructions from Earth, AEGIS could direct the rovers' high-resolution cameras, spectrometers, and thermal imagers to gather data about the rocks of interest.

"Using AEGIS, the rovers could get science data that they would otherwise miss," says Rebecca Castaño, leader of the AEGIS project at JPL. The software builds on artificial intelligence technologies pioneered by NASA's Earth Observing-1 satellite (EO-1), one of a series of technology-test bed satellites developed by NASA's New Millennium Program.

AEGIS identifies a rock as being interesting in one of two ways. Mission scientists can program AEGIS to look for rocks with certain traits, such as smoothness or roughness, bright or dark surfaces, or shapes that are rounded or flat.

In addition, AEGIS can single out rocks simply because they look unusual, which often means the rocks could tell scientists something new about Mars's present and past.

The software has been thoroughly tested, Castaño says, and now it must be integrated and tested with other flight software, then uploaded to the rovers on Mars.  Once installed, she hopes, Spirit and Opportunity will leave no good Mars rock unturned.

Check out other ways that the Mars Rovers have been upgraded with artificial intelligence software at:

http://nmp.nasa.gov/TECHNOLOGY/infusion.html#sciencecraft

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

GO TO INDEX

CONTACTS

Chairman   John Vale-Taylor 

Phil Berry  01892 783544

Treasurer  Mike Wyles  01892 542863

Publicity & Website  Michael Harte  01892 783292

Any material for inclusion in the March 2008 Newsletter should be with the Editor by February 28th  2008

GO TO INDEX