WADHURST ASTRONOMICAL SOCIETY

NOVEMBER NEWSLETTER 2007

INDEX: MEETINGS, OTHER NEWS, CONTACTS

THE SOCIETY CELEBRATES ITS TENTH YEAR!

The Wadhurst Astronomical Society will be ten years old this November!

Eleven years ago, several keen students joined a GCSE Astronomy course at Uplands College run by Rob Cray.

At the end of the year's course these successful students met in the Greyhound pub next to Uplands College and discussed the exciting possibility of forming an Astronomical Society in Wadhurst.

It was agreed that there was sufficient interest and a Committee was set up to run the Society with meetings to be held in the Drama Studio at Uplands College once a month and the Wadhurst Astronomical Society was born.

The Society grew and was a great success.

Rob continued to lead, giving many talks at the meetings and giving encouragement in both practical and theoretical astronomy.  Other interested individuals joined the Society, now called the Wadhurst Astronomical Society and linked together with other groups within the Federation of Astronomical Societies.

The Society obtained two telescopes for members to use and Murray Barber, who joined the Society soon after it was formed, built another, this time with a Dobsonian mount.

From the original core we have Joan Grace, Tim Bance and Rob Cray, who still comes to meetings whenever he can as our honorary member.

Ian Reeves was one of the original members but sadly died last year.  Ian was very important to the Society in taking on the post of Secretary at a time when many changes were taking place including the change the of venue to the Methodist Church Upper Room in November 2005 when it became too expensive to remain at Uplands.

Mavis, Ian's widow very kindly donated Ian's Konus 120 mm refracting telescope to the Society and it is available for any full member of the Society to borrow, as are the other three telescopes.

During the ten years of the Society, There have been many varied events and speakers.  To promote the interest in Astronomy, we have attended local events, demonstrating telescopes and providing material and information for the General Public.

The talks have covered subjects as diverse as archaeological searches for old observatories to the very latest news from Mars.  We have had a display of actual pieces of moon dust that had been brought back to earth during the Apollo missions.  There have been demonstrations of telescope building and talks by members on problems and solutions whilst observing.

Visits have included an evening spent on the observatory on the University of Hertfordshire's Facility at Hertingfordbury, and very recently to see the private collection of clocks at Belmont House near Faversham under the guidance of the Curator of Horology at Greenwich Observatory.With the enthusiasm of its members, the Society looks set to continue well into the future.

"Happy Birthday"!

MEETINGS

OCTOBER MEETING

Keith Brackenborough

The Calendar - A 5,000 year struggle to align the clock with the Heavens - The talk given at the Society's meeting on October the 17th.

Keith Brackenborough is a member of the Eastbourne Astronomical Society and also is the current Chairman of SAGAS, the Southern Area Group of Astronomical Societies.

He began his talk by referring to the influence that Astronomy, Astrology and Religion had had on the development of the calendar as we know it today and how important a common calendar is in recording historical events such as the Battle of Hastings in 1066 and the attack on the Twin Towers in New York in 2001.

In passing Keith also mentioned the millennium and how it was celebrated a year too early because there had been no "year zero".

In the 5,000 years it has taken to develop the calendar as we recognise it, various influences have brought about many changes such as Stonehenge, religion, astrology and cultures.

From the earliest recorded times 12 lunar months were used to dived the year and various methods of correction were attempted to reduce the conflict between the lunar year and solar year.

The Egyptians needed to be able to predict when the Nile would flood and had calculated that the year had 365 days.  At the time the first sightings of Sirius had been used to measure the year.

Keith told us that different peoples used different methods of measuring and correcting the year.  The Egyptians used correction days to attempt to align the lunar and solar year by adding a number of days.  Even this system accumulated an error and every 4 years another day was added to the calendar.

The Early Romans divided the year into 10 months, 6 of 30 days and 4 of 31 days making 304 days beginning in March and ending in December with what seems to have been an uncounted winter gap.  January and February were later added to fill the gap with 50 days, other days being taken from some of the other months to add to these months.  The Romans had developed a superstitious dread of even numbers so January was given and extra day.  Their calendar now had 355 days.

Julius Caesar came along later and with advice changed their calendar to the Egyptian system with 365 1/4 days with the year beginning on January the first.  The Julian calendar had 365 days with an extra day being added during February.

Caesar also changed the name of the seventh from Quintilis to Julius (which became July) to preserve his name.  Augustus changed the name of the month called Sextilis to Augustus (August) for the same reason and also had the number of days in the month changed so that his month at least had the same number as Julius.

In 1266 Roger Bacon criticised the remaining error in the Julian calendar, saying that eventually summer would be in winter.

The Julian calendar was slowly becoming out of step with the seasons.  Pope Gregory attempted to address this problem by introducing a bill promulgating that three out of every four centennial years should not be leap years.  The Gregorian calendar

Keith mentioned that Dionysius in the sixth century devised a system of numbering the years in Anno Domini when numbering Easter dates.  This system is now recognised internationally.

Because of religious links, King Henry VIII refused to have anything to do with Julian dates and at one time Scotland and England actually used different systems.

In 1750, England was out of step by 11 days and Philip Stanhope who on the death of his father became Lord Chesterfield introduced a bill in parliament, which was passed in 1751, stipulating that the day after September the second, 1752 should be September the fourteenth.  At this time the English calendar was changed to start the year on January the first instead of March the 25th.

A member of the Society said that one man in Thetford died and was buried during this time and on his gravestone both September dates are shown as his date of death!  Another member said that legal documents of the time are still causing a great deal of confusion.  It was also stated that Nepal is still 57 years ahead according to their calendar...

Keith pointed out one interesting fact that the financial year we use for Tax purposes was still left as the 25th of March and with the loss of eleven days this became April the fifth!  This was later changed to the sixth where it remains to this day.

The last countries to accept the new calendar were Greece in 1923, Turkey in 1926 and China in 1949, although Chinese New Year is still celebrated informally on the seventeenth of February (this year would be 4705) .

Keith's talk contained far more numerical detail and interesting facts than is shown here but his talk was both informative and entertaining and all was convincingly done without the use of any visual aids other than his enthusiasm.

NOVEMBER MEETING

Wednesday 21st November 2007.  There had to be a change from the original programme so Phil Berry will be introducing two half-hour videos.  One is called "The Intrinsic Brightness of Stars" and the other, "The Structure of the Milky Way Galaxy".  They are instructional videos and part of a structured course.  Phil is keen to hear what Members feel about using other videos in the series.

The meeting begins at 1930 although members are invited to arrive anytime after 1900.  The venue as always is in the Upper Room of the Methodist Church at the east end of Wadhurst High Street, opposite Uplands College.  The room downstairs is used by "Weight Watchers".

FUTURE MEETINGS & EVENTS

Wednesday 12th December 2007  NOTE: THIS IS THE SECOND WEDNESDAY OF DECEMBER   Society Member, Paul Treadaway is giving a talk he calls "Why are we Still Here?" - Food for thought...

Further thought for food! - Mince pies and coffee will be at the meeting to celebrate the season!

Wednesday 16th January 2008  The talk is still to be announced but will be followed by the Society's Annual General Meeting.

GO TO INDEX

OTHER NEWS & INFORMATION

SKY NOTES FOR NOVEMBER

Planets

Mercury will be visible in the morning sky for the first part of the month reaching greatest western elongation on the 8th. It will then rise about an hour and a half before the sun and shine at magnitude -0.5.

Venus is a brilliant morning object rising around four hours before the sun. At magnitude -4 it will display a gibbous phase when viewed through a small telescope.

Mars at magnitude -1 is growing in size as it approaches opposition. It lies in the constellation of Gemini (the twins) and rises around 19.00 by the middle of the month.

Jupiter is poorly placed for observation this month, setting soon after the sun.

Saturn is a morning object rising at around 01.00 in the constellation of Leo (the lion). As I mentioned earlier in the year the ring system is closing up (becoming more edge on) as seen from Earth and consequently its brightness has fallen to 0.7.

Lunar Occultations

Below are the events involving reasonably bright stars (down to around 7.5) that occur before midnight. Times are all GMT. DD = Disappearance on the Dark limb whilst RD = Reappearance on the Dark limb.

Date Time Star (SAO Catalogue) Constellation Magnitude Phase PAš
Tue 13th 1710 186328 Sagittarius 4.6 DD 37
Sat 17th 2151 164647 Capricornus 7.7 DD 15
Mon 19th 2201 146712 Aquarius 7.6 DD 133
Mon 19th 2214 146712 Aquarius 7.6 RD 156
Tue 20th 2054 109094 Pisces 7.1 DD 10
Fri 23rd 1646 Epsilon Arietis Aries 5.2 DD 18
Fri 23rd 1646 Epsilon Arietis Aries 5.5 DD 18

There are a couple of interesting occultations in the list. The first is on the 19th November when SAO 146712 suffers both a disappearance and reappearance within thirteen minutes of each other. Both of these events occur on the dark limb. The second is on 23rd November when a star that is a binary double is occulted with the two components disappearing within a second of each other.

Meteors

There are two showers of interest during November. Firstly the Taurids with their double radiant reach maximum on 3rd November. The shower continues until the end of the month but with only limited activity although any meteors you see are likely to be bright and slow.

Secondly the Leonids are active from 15th to the 20th November with the maximum occurring on 18th at around 05.00 GMT. The Leonids are known to suffer outbursts when the Earth passes through a particularly rich stream of material left behind by the comet 55P/Temple-Tuttle. Predictions are that a reoccurrence of the storms of previous years are unlikely before the 2020's although of course it's difficult to be certain. However any meteors you see could well be very fast with the brighter ones leaving ionised trails that could last from a few seconds up to a minute or so.

ISS

Unfortunately there are no evening appearances of the ISS this month; they all occur around 04.00 to 06.00. If you are an early riser you can log on to the web-site for more details: - www.heavens-above.com

Advance Notice

The maximum of the Geminid meteor shower occurs on December 14th.

Brian Mills

NASA SPACE PLACE

The Red (Hot?) Planet

by Patrick L. Barry

Don't let Mars's cold, quiet demeanour fool you. For much of its history, the Red Planet has been a fiery world.

Dozens of volcanoes that dot the planet's surface stand as monuments to the eruptions that once reddened Mars's skies with plumes of glowing lava. But the planet has settled down in its old age, and these volcanoes have been dormant for hundreds of millions of years.

Or have they? Some evidence indicates that lava may have flowed on Mars much more recently. Images of the Martian surface taken by orbiting probes show regions of solidified lava with surprisingly few impact craters, suggesting that the volcanic rock is perhaps only a million years old.

If so, could molten lava still occasionally flow on the surface of Mars today?

With the help of some artificial intelligence software, a heat-sensing instrument currently orbiting Mars aboard NASA's Mars Odyssey spacecraft could be just the tool for finding active lava flows.

"Discovering such flows would be a phenomenally exciting scientific finding," says Steve Chien, supervisor of the Artificial Intelligence Group at JPL. For example, volcanic activity could provide a source of heat, thus making it more likely that Martian microbes might be living in the frosty soil.

The instrument, called THEMIS (for Thermal Emission Imaging System), can "see" the heat emissions of the Martian surface in high resolution-each pixel in a THEMIS image represents only 100 meters on the ground. But THEMIS produces about five times more data than it can transmit back to Earth.

Scientists usually know ahead of time which THEMIS data they want to keep, but they can't plan ahead for unexpected events like lava flows. So Chien and his colleagues are customizing artificial intelligence software called ScienceCraft to empower THEMIS to identify important data on its own.

This decision-making ability of the ScienceCraft software was first tested in Earth orbit aboard a satellite called Earth Observing-1 by NASA's New Millennium Program. Earth Observing-1 had already completed its primary mission, and the ScienceCraft experiment was part of the New Millennium Program's Space Technology 6 mission. 

On Odyssey, ScienceCraft will look for anomalous hotspots on the cold, night side of Mars and flag that data as important. "Then the satellite can look at it more closely on the next orbit," Chien explains.

Finding lava is considered a long shot, but since THEMIS is on all the time, "it makes sense to look," Chien says. Or better yet, have ScienceCraft look for you-it's the intelligent thing to do.

To learn more about the Autonomous ScienceCraft software and see an animation of how it works, visit http://ase.jpl.nasa.gov .

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  pjvalet@tiscali.co.uk

Phil Berry  01892 783544 phil.berry@tiscali.co.uk

Treasurer  Mike Wyles  01892 542863 mikewyles@globalnet.co.uk

Publicity & Website  Michael Harte  01892 783292 was@greenman.demon.co.uk

Newsletter Editor  Geoff Rathbone  01959 524727 Geoff@rathbone007.fsnet.co.uk

Any material for inclusion in the December Newsletter should be with the Editor by November 28th  2007

GO TO INDEX