MEETINGS

There is to be a meeting of the Committee at Phil Berry’s house beginning at 1930 on Tuesday 9^th of February. This replaces the one that would have taken place earlier had it not been for the snow.

As always, any member of the Society is welcome to join us, although please let Phil know before hand.

JANUARY MEETING

The Annual General Meeting 2010

Our Chairman, John Vale-Taylor addressed the meeting and told members that the Society had achieved an interesting year with a varied selection of talks and we had also had a visit to the Time Galleries at Greenwich Observatory museum guided by Jonathan Betts who gave an excellent background to the way in which Greenwich had progressed through time measurement and providing the world with ever increasingly accurate time signals.

Our Treasurer, Michael Wyles presented a statement of receipts and payments by the Society over the past year. Our accounts remain healthy with our Current Account standing at £197.02 and the Reserve at £1170.00. There has been a very modest increase in the hire of the Room, but there is some work being done in reducing our financial commitment to the Federation of Astronomical Societies.

Geoff Rathbone, the Newsletter editor noted that the Newsletter now contained illustrations and asked if this had caused problems when downloading it. Everyone present seemed to be receiving their copy without problems. He also asked for suggestions or anything more to be included in it. One suggestion was that we have the profile of one member each month.

Phil Berry announced that at the request of the Southern Area Group of Astronomical Societies (SAGAS) he had taken on the roll of Secretary. It is now felt that we need one or two more members on the Committee and the Chairman asked members to think about it.

Phil said that already a number of new talks have been arranged for the next few months.

Our Director of Observations, Brian Mills, had previously designed and issued a questionnaire asking for member’s views of how the Society, particularly the meetings are being run. He had received back a number of them and they gave the impression that members were generally satisfied, although it was suggested that we include more talks on the planets, the Sun and the birth and death of stars. It was also felt that we should have more observing sessions beginning with a proposal that when possible, we should have a practical viewing session immediately after our meetings if the sky is clear when we could learn basic sky recognition.

The meeting continued with a talk by our own Jan Drozd describing some very interesting models of instruments he had made.

My Replica Astronomical Instruments and Models

Jan Drozd

To set the background to his talk, Jan introduced us briefly to some of the most influential Astronomers in history, beginning with Ptolemy, and covering Hipparchus, Tycho Brahe, Galileo, Kepler to Newton.

Ptolemy was the astronomer who gave the constellations their names. Tycho Brahe, circa 1590 had already produced a number of astronomical instruments, even before the telescope.

Lenses had been known about and used from as early as 1350, well before Lippershey, a German-Dutch lens maker made the first telescope with about three times magnification.

Galileo developed the Lippershey telescope to a magnification of about 14 with a virtual image.

Jan produced a replica of one of Galileo’s telescopes and we were astonished to discover that Galileo would only have had a field of about 15 arc-minutes, which would have enabled him to observe just a quarter of the moon.

With this telescope Galileo determined that Venus had phases meaning it was a planet between the Earth and the Sun.

Also with this very narrow field of view, He was able to make drawings of the four most visible moons of Jupiter, determining that they were Jovian moons, although he thought Saturn was a planet with “ears”. Galileo also found that the Milky Way consisted not of a cloud but of millions of stars.

Sadly, the Catholic Church put Galileo’s books on a prohibited list in 1633 and was only to remove them from the list in 1824.

We were then told that Kepler succeeded in using a convex lens system to produce an inverted image which allowed more light to pass through the telescope.

Kepler was employed as a court astrologer, although he began to understand the working of the heavens, yet for a time he believed that the solar system could be depicted as a series of polyhedrons, although he was later to abandon this idea.

At this stage Jan produced a very realistic model of Kepler’s polyhedrons.

After very careful measurements of the solar system, Kepler realised that the only way the planets could behave in the way they did was if they were in elliptical orbits. He then produced his laws to explain this. These laws are known today as Kepler’s Laws of planetary motion.

The next model Jan produced was of an Armillary Sphere which had originally been made of a series of brass rings forming the outlines of concentric spheres with the Earth in the centre. Each ring was etched with scales capable of predicting such things as the Sun’s right ascension. It mainly ended up as “something to sit on the coffee table”!

The next model was of an astrolabe, used by ancient astronomers and navigators to measure and predict the positions of the Sun, moon and planets.

Jan then discussed the orrery, although this is something he has a kit for but needs time to construct it in “peace and quiet”.

He showed an Astronomical Ring Sundial used in about 1600, but then produced another of his models, this time of an impressive Sextant, used for “shooting” the Sun at noon by navigators. In fact Jan said some one he knew had used his cardboard model in anger and found it to be rather accurate.

In referring to how ingenious some of the ancient astronomers were, we were shown a picture of the Antikythera Mechanism discovered in about 1900 but whose purpose remained unknown due to its extraordinary complexity. It had been found in the wreck of a ship just off the Greek island of Antikythera and is thought to be from about 100 BC. It is now believed to have been capable of making astronomical calculations.

Finally we were introduced to a working model of a hand spectroscope which we were able to use and see the Fraunhofer lines produced by the discharge lamps that illuminate the room in which we meet.

Jan gave the Internet address of the company from whom he obtains the kits for his models as:

www.astromedia.de/

Another site he recommended was:

www.green-witch.com

and another at:

http://curiousminds.co.uk

FEBRUARY MEETING

Wednesday 17^th February 2010 – Greg Smye-Rumsby talks about “Bits and Bobs”. He has visited us on a number of occasions and members will remember his inimitable style; not only hilarious but also very informative.

Greg is a regular contributor to Astronomy Now and often produces the graphics for various articles. He can often be found giving talks in the Greenwich Observatory’s Peter Harrison Planetarium.

Meetings begin at 1930 although members are invited to arrive anytime after 1900 as this is a good time to exchange ideas and discuss problems and relax before the talk.

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

FUTURE MEETINGS

Wednesday 17^th March 2010 – James Fradgley from Wessex Astronomical Society in Wimborne, Dorset gives a talk entitled “Life in the Universe”

Wednesday 21^st April 2010 – Dave Styles from Ashford Astronomical Society will be talking about “The Ice Giants”.

OTHER NEWS AND INFORMATION

THIS YEAR’S PROPOSED VISIT

Phil announced at the January meeting that two venues were being considered for this year’s visit. One was to Surrey Satellite Technology near Guildford but members present preferred a proposed visit to see the telescopes at Herstmonceux, so Phil is looking into the feasibility and will give further information later. The trip would probably be a Saturday sometime in April or May.

SUBSCRIPTIONS 2010

We have now entered a new session of the Society and again, the subscriptions remain the same as in recent years. Membership for the year is still £15.00 and £20 for two members within the same family. Children and students are free and always welcome.

Subscriptions can be made at the meetings, preferably by cheque payable to “Wadhurst Astronomical Society”. Or can be posted to our Treasurer, Michael Wyles at:

31 Rowan Tree Road

Tunbridge Wells

Kent

TN2 5PZ

MEMBER PROFILE

It has been suggested that the Newsletter has a profile of one member each month. I hope this isn’t too forward but it is easier for me as Editor to include mine first and get it over with... So I hope you will forgive me.

Geoff Rathbone

When I was just 5, my history teacher was talking about navigators using the Plough to find the Pole star, when she mentioned that Mizar was a double star and that through a telescope that was yet another double star. I sat up and was hooked. In those days the sky was very clear – there were no lights on during the war!

I built my first telescope using a cracked projector lens from the local cinema together with some spectacle lenses provided by my uncle. Pretty awful until I had saved up enough to by a 6” mirror and real eyepieces!

I joined the British Astronomical Association who helped with understanding mathematical formulae which brought a whole new meaning to amateur astronomy.

I tried imaging using an old film camera but without much success. Then along came Starlight Express and with my new computer I was at last able to produce more satisfying images, but looking back on what amateurs produce now I am happy to just observe whenever I can with my rather old 11” Celestron Schmidt-Cassegrain.

The view from my house is like looking up a funnel because of trees and light pollution, so I have to lug the telescope out with its German equatorial mount and set it up wherever I can. I still enjoy the challenge of setting the telescope up before serious viewing; that’s if I’m not puffed out carrying it…

I suppose my knowledge is a bit old fashioned now and I probably would be referred to as “An Armchair Astronomer” and have become much more interested in theoretical astronomy, although I do still observe the Sun every few days, which I enjoy despite the Sun having been rather quiet of late.

Late in the 50s I became a Fellow of the British Interplanetary Society. Goodness knows where I think I’m going!

SKY NOTES FOR FEBRUARY

Planets

Mercury is a morning object but is really too low in the sky to be readily identified. It suffers a superior conjunction on March 14^th after which it puts on its best evening show for 2010.

Venus at magnitude -3.8 is an evening object but is also very close to the horizon in the west. However the observing opportunities improve steadily with the planet being on view for a large percentage of the year.

Mars at magnitude -1.0 lies in the constellation of Cancer and is visible almost all night. It is moving retrograde at the moment (east to west) and continues to do so until 11^th March. Its position is shown on the map under “Saturn” below. The planet was at opposition in January since when it has been decreasing in both apparent size and brightness. Opposition occurs when a planet, the Earth and the Sun all line up with the Earth in the middle. See diagram below.

Jupiter at magnitude -2.0 may be seen low down in the west at sunset at the beginning of the month. However it is in conjunction with the Sun on the 28^th and will be lost to our view until May when it will be a morning object.

Saturn rises at around 20.30 (mid month) at magnitude +0.7 in the constellation of Virgo where it is currently moving retrograde. The rings have only opened by a few degrees with the north pole of the planet tilted slightly towards us. Its position is shown in the diagram below.

Lunar Occultations

As usual in the table I’ve only included events for stars down to around magnitude 7.0 that occur before midnight. DD = disappearance at the dark limb and RD = reappearance at the dark limb.

If anyone would like more information about these occultations or times for fainter events then please let me know. The events on the 20^th are occultations of the double star Epsilon Arietis with components separated by 1.5 arc seconds. On the 21^st the Moon skirts the southern part of the Pleiades cluster in Taurus. Times are all GMT.

Feb.	Time	Star	Mag.	Ph	PA °
17^th	19.34	SAO 109168	6.8	DD	106
20^th	23.00	XZ 54005	4.6	DD	40
20^th	23.00	SAO 75673	4.7	DD	40
21^st	18.53	SAO 76189	7.0	DD	50
21^st	19.06	SAO 76193	7.0	DD	29
21^st	19.30	SAO 76215	5.4	DD	132
21^st	20.00	SAO 76225	6.5	DD	29
21^st	20.08	SAO 76244	6.2	DD	72
21^st	20.27	GSC 0180001260	5.9	DD	40
21^st	20.27	SAO 76251	6.8	DD	40
24^th	17.29	SAO 78771	6.8	DD	119
25^th	19.35	SAO 79799	5.4	DD	62
27^th	21.06	SAO 118001	5.8	DD	37
27^th	21.15	SAO 118001	5.8	RD	21
27^th	21.57	SAO 118023	6.1	DD	130
27^th	23.07	SAO 118044	4.7	DD	122

Phases of the Moon

Last ¼	New	First ¼	Full
5^th	14^th	22^nd	28^th

ISS

There are no passes of the ISS this month that occur before midnight - they all occur in the early hours of the morning. Details of all passes can be found at:

www.heavens-above.com

Iridium Flares

The flares that I’ve listed are magnitude -3 or brighter. There are many more flares that are fainter, occur at lower altitudes or after midnight. If you wish to see a complete list, go to www.heavens-above.com Times are all GMT. Remember that when one of these events is due it is often possible to see the satellite in advance of the “flare”, although of course it will be much fainter at that time.

Feb	Time	Mag	Alt°	Az.
7^th	17.09	-8	74	NE
15^th	19.12	-4	46	SE
20^th	18.51	-4	49	SSE
23^rd	17.50	-6	66	NNE
25^th	18.30	-3	51	SSE

Retrograde Motion

Due to the west to east rotation of the Earth all of the heavenly bodies are carried from east to west on a daily basis although quite apart from this many have their own proper motions. The outer planets appear to move steadily eastwards compared to the stars except for short periods when they seem to stop and go backwards (westwards).

This is because the Earth has overtaken the slower planet “on the inside” as demonstrated in the diagram.

Observing

The occultations that I mentioned above that take place on the 21^st would present an ideal opportunity for some members who would like to try a little observing to get together and do it in a group. The advantage is that complete novices can be given guidance by those with more experience and it doesn’t really matter if you get things wrong. The society has a couple of scopes plus a few that members have, so I’m sure there would be enough to go round. Let me know at the e-mail address at the end of this newsletter if you think you would like to take part.

Brian Mills

NASA’S SPACE PLACE

Building a Case Against Ozone

by Patrick Barry

When it comes to notorious greenhouse gases, carbon dioxide is like Al Capone—always in the headlines. Meanwhile, ozone is more like Carlo Gambino—not as famous or as powerful, but still a big player.

After tracking this lesser-known climate culprit for years, NASA’s Tropospheric Emission Spectrometer (TES) has found that ozone is indeed a shifty character. Data from TES show that the amount of ozone—and thus its contribution to the greenhouse effect—varies greatly from place to place and over time.

"Ozone tends to be localized near cities where ozone precursors, such as car exhaust and power plant exhaust, are emitted," says Kevin Bowman, a senior member of the TES technical staff at the Jet Propulsion Laboratory. But the ozone doesn't necessarily stay in one place. Winds can stretch the ozone into long plumes. "Looking out over the ocean we can see ozone being transported long distances over open water."

Unlike CO₂, ozone is highly reactive. It survives in the atmosphere for only a few hours or a few days before it degrades and effectively disappears. So ozone doesn't have time to spread out evenly in the atmosphere the way that CO₂ does. The amount of ozone in one place depends on where ozone-creating chemicals, such as the nitrogen oxides in car exhaust. are being released and which way the wind blows.

This short lifespan also means that ozone could be easier than CO₂ to knock off.

"If you reduce emissions of things that generate ozone, then you can have a quicker climate effect than you would with CO₂," Bowman says. "From a policy standpoint, there’s been a lot of conversation lately about regulating short-lived species like ozone."

To be clear, Bowman isn’t talking about the famous "ozone layer." Ozone in this high-altitude layer shields us from harmful ultraviolet light, so protecting that layer is crucial. Bowman is talking about ozone closer to the ground, so-called tropospheric ozone. This "other" ozone at lower altitudes poses health risks for people and acts as a potent greenhouse gas.

TES is helping scientists track the creation and movement of low-altitude ozone over the whole planet each day. "We can see it clearly in our data," Bowman says. Countries will need this kind of data if they decide to go after the heat-trapping gas.

Ozone has been caught red-handed, and TES is giving authorities the hard evidence they need to prosecute the case.

Learn more about TES and its atmospheric science mission at:

tes.jpl.nasa.gov.

The Space Place has a fun “Gummy Greenhouse Gases” activity for kids that will introduce them to the idea of atoms and molecules. Check it out at:

spaceplace.nasa.gov/en/kids/tes/gumdrops.

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

Caption:

These images are TES ozone plots viewed with Google Earth. Colors map to tropospheric ozone concentrations. The image on the left shows ozone concentrations at an altitude of approximately 32,000 feet, while the one on the right shows ozone at approximately 10,000 feet. The measurements are monthly averages over each grid segment for December 2004.

CONTACTS

Chairman John Vale-Taylor

pjvalet1@btinternet.com

Secretary & Events Phil Berry 01892 783544

phil.berry@tiscali.co.uk

Treasurer Mike Wyles 01892 542863

mike31@madasafish.com

Editor Geoff Rathbone 01959 524727

geoff@rathbone007.fsnet.co.uk

Director of Observations Brian Mills 01732 832691

Brian@wkrcc.co.uk

Wadhurst Astronomical Society website:

www.wadhurst.info/was/

SAGAS web-site www.sagasonline.org.uk

Any material for inclusion in the March 2010 Newsletter should be with the Editor by February 28^th 2010