WADHURST ASTRONOMICAL SOCIETY

MARCH NEWSLETTER 2009

INDEX: MEETINGS, OTHER NEWS, CONTACTS

MEETINGS

 

FEBRUARY’S TALK

 

Earth and its Environment from an Astronomer’s Perspective

Talk by Dr Jan Drozd

 

       Jan is a Society member who spent much of his working life with Shell Oil, first as a chemist and then presenting talks on the Environment.  Together with his interest in astronomy, he has developed this talk for tonight’s presentation.

       He began his talk by making us aware that environmental change is as old as the Earth itself, with life having a large impact.  Man himself has continually altered the environment but worryingly, nothing like as much as in the twentieth and twenty-first centuries.

       We looked at our Earth relative to the rest of the known Universe out to more than 12 billion light years.  Using some remarkable images we were left with the distinct awareness that we are an island quite remote from our nearest neighbours - in Man’s terms, that is.

       Life began very quickly after the Earth was formed, four billion years ago.  Jan used the most recent theories to explain how the Moon had been created possibly from an encounter with a Mars-sized object.

       To begin with water had collected from volcano condensation and from invading comets to form the seas.

       Then using an animation, he showed how the Earth’s crust moved to divide the one huge land mass known as Pangaea in a process called Plate Tectonics, to form the great continents as they are today.

       Tables and charts were used by Jan to show how the Earth’s atmosphere has changed.  Originally the Earth was an airless ball of molten rock.  As the planet cooled, escaping gasses produced water, nitrogen, carbon dioxide and ammonia.  Over time sunlight split the NH3, ammonia, into nitrogen and hydrogen although the hydrogen was subsequently lost to space.  Much of the carbon-dioxide was dissolved in the water to form carbonate rocks.

       About 2 billion years later oxygen begins to appear in the atmosphere due to chlorophyll photosynthesis.

       This process continues and about a billion years ago, the atmosphere begins to resemble the atmosphere we have today.

       Jan compared ourselves with our neighbours in the Solar system and showed why we have conditions that are excellent for life as we know it.

       The Moon has had insignificant out-gassing and it has too little gravity to retain virtually any atmosphere, therefore the temperature is either -173o C or +100o C.

       Venus may once have been like Earth but because of its close proximity to the Sun water vapour accelerated the “greenhouse” effect.  The temperature now reaches an uncomfortable 500o C with an atmosphere composed almost entirely of CO2 at 90 times the atmospheric pressure on Earth.

       Mars doesn’t fare much better.  It does have a weak atmosphere of CO2 and has temperatures as low as -60o C and struggles to reach zero although there is evidence that water once flowed the planet’s surface.

       We were shown a graph of star size against distance from the primary star around which the planets orbited, indicating the habitable zone with the Earth right in the middle of this zone.

       In fact very many things control the Earth’s climate; Greenhouse gases, Ocean currents, the Sun’s intensity, changes in the Earth’s orbit, living organisms and many other factors.

       We looked at a diagram that showed how some of the energy from the Sun can be reflected by the earth and the atmosphere, yet about half of the Sun’s radiation is absorbed by the Earth and heats its surface.  Some of this energy is re-radiated as infra-red out into space but much is re-emitted in all directions by the greenhouse gases in the atmosphere which in turn warms the surface and lower atmosphere.

       Something else that drives the ice-ages is the combined effect of the Earth’s tilt, eccentricity and precession, resulting in what is known as the Milankovitch Cycle.

       It is thought that perhaps 20 times in the existence of the Earth, a set of circumstances have occurred when huge ice sheets have covered much of the surface.  The last ice-age ended about 10,000 years ago having lasted 110,000 years.

       Then Jan showed an illustration of how the Earth has a built-in “Thermostat”.  Volcanoes produce CO2, keeping the Earth warm and evaporating sea water to produce rain.  This in turn washes out the CO2 and the now the slightly acidic rain washes out minerals from rocks which end back in the sea where the minerals precipitate out to form new carbon-containing rocks.  The CO2 eventually leaves the mantle via volcanoes and so completes the cycle and so helps regulate the temperature of the Earth’s atmosphere.

       All this can be monitored by looking at tree rings, corals, ice-cores and historical records.

       Alarmingly it has been found that in the last two hundred years CO2 in the atmosphere and the surface temperature of the Earth have increased dramatically.  At the same time human population has also increased equally spectacularly and also many of us are living longer.

       One remarkable photograph Jan showed us was a composite night image of Earth taken from space and the outline of the continents were clearly defined.  Another animation showed how quickly the glaciers are retreating.

       We are using the Earth’s resources before they can be replaced at the same time as we are producing more and more pollution and waste. The Earth carries with it all the limited available resources in its journey through space and they can’t be replaced.

       The Astronomer Royal, Martin Rees, predicts that one of two outcomes is inevitable for humanity:  Human extinction from Man’s technology, uncontrolled scientific research, terrorist or fundamentalist violence or destruction by the biosphere.  Or the other outcome:  Human expansion throughout space, by minimising, avoiding or overcoming these problems.

       In about 250 million years, the land masses are expected to come together again.  After 500 million years 95% of plant life dies out because of lack of carbon dioxide.  After 1,200 million years the Earth’s surface temperature is expected to reach 60o to 70o, then the oceans boil off and all complex life has died out.

       After this the Moon drifts too far away to stabilise the Earth’s spin and eventually the Sun becomes a Red Giant, runs out of fuel and becomes a White Dwarf.

       But Man may still have it within his grasp to at least slow down climate change but he will have to be very quick and it will need common global effort.

       Jan summed Man’s present attitude with a cartoon showing Man boasting that “Global warming is a complete myth – but to stay away from the edge!”

 

TELESCOPES: THEIR ADVANTAGES AND DISADVANTAGES

 

       After a coffee break there followed the first of a series of short talks about astronomical equipment and its use.  We began with an introductory talk about basic telescopes.

 

THE SKY IN MARCH

 

       The meeting concluded with a short introduction to the constellation of the Plough and its surroundings.

       Brian provided an information sheet and chart for members to take away for reference.

 

MARCH MEETING

 

       Wednesday 18th March 2009 “The Apollo Programme – Missions 1 to 12” a talk to be given by Rob Cray who is the founder member of our Society.  He led a course in Astronomy at Uplands College over ten year’s ago and he and his class formed the Society to continue their interest in the subject.

       Later in the year Rob will return to talk about the remaining Apollo missions.

       The meeting begins at 1930 although members are invited to arrive anytime after 1900 as 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, and opposite the entrance to Uplands College.  (For those with SatNav – the post code is TN5  6AT)

 

FUTURE MEETINGS

 

       Wednesday 15th April 2009 “The Sun Kings”, a talk to be given by Stuart Clark.  Stuart is one of the UK’s foremost astronomy journalists; in fact he is a former editor of Astronomy Now.  His talk takes us through the tragic life of Richard Carrington and tells how modern astronomy began.

       Wednesday 20th May 2009 “Sputnik in Context” a talk by John Axtell who is a member of Guildford Astronomical Society, but is better known to members of WAS as the Secretary of the Southern Area Group of Astronomical Societies – SAGAS.

 

OTHER NEWS AND INFORMATION

      

SIGNING UP.  SWITCH OFF!!!

 

       On Saturday 28 March 2009 at 2030, people, businesses and iconic buildings around the world will switch off their lights for one hour – WWF’s Earth Hour.  WWF want a billion people around the world to sign up and switch off their lights for one hour.   See: http://www.wwf..org.uk/how_you_can_help/earthhour/

       If they achieve their billion people it will send a powerful message - Suggest all Astronomers Sign Up Now !

 

VISIT TO SEE THE GREENWICH CLOCKS

 

       On Saturday the 21st of March the Society is visiting the Old Observatory at Greenwich again, this time to see the collection of clocks under the guidance of Jonathan Betts who was our expert guide when we visited Belmont House to see the largest private collection of clocks in Europe.  Jonathan is the Senior Specialist in Horology at Greenwich Royal Observatory.

       Below is a list of members going on this Greenwich visit:

 

             Stephen Anderman           Michael Berks

             Phil Berry                         Rose Bond

             John Daw                         Jan Drozd

             Douglas Hall                    

             Alexander Helm                Gavin Mills

             Brian Mills                        Larry Mowat

             Robert Pike                      Geoff Rathbone

             Peter Rathbone                 Isobel Tucker

             Tommy Tucker                  John Vale-Taylor

             Michael Wyles                  Ian McCartney

 

       The group has now reached the maximum number we can accommodate.

       We will meet at 0945 by Greenwich Observatory in Greenwich Park by the Wolfe Statue which is at the end of Blackheath Avenue, ready to begin the tour promptly at 1000.

       Members need to find their own way to Greenwich Park but there is an opportunity to arrange shared travel arrangements at the next meeting of the Society which is on Wednesday the 18th of March, just before our visit the following Saturday.  More details will be available at that meeting.  For those with SatNav, the post code of the Observatory is SE10 8XT.

       We have also been offered a tour of part of the National Maritime Museum beginning at 1415.  It might help if those taking advantage of this extra tour make sure their names ar added to the list held by Phil Berry if they haven’t already done so. The list will be at the next meeting.

       For this added tour we will meet at the Stanhope Entrance, which is the main entrance of National Maritime Museum and is on the North side of the Museum, in Romney Road.

       More information will be available at our next meeting.

 

SUBSCRIPTION FOR THE 2009 SESSION

 

       Subscriptions for the current session of Wadhurst Astronomical Society became due on the first of January.  They remain the same as previous years with adult membership at £15 and £20 for two members within the same family.  Student membership is free.

       Subscriptions can be sent direct to the Treasurer, Mike Wyles  at 31 Rowan Tree Road, Tunbridge Wells, Kent TN2 5PZ or can be paid at the meetings.

       Mike prefers to receive a cheque payable to "Wadhurst Astronomical Society" although cash is fine.

 

UK SPACE CONFERENCE

 

       All Astronomical Societies in the Southern Area Group of Astronomical Societies have received the following note:

 

       The UK Space Conference will be taking place at Charterhouse School near Godalming, Surrey and SAGAS is providing support to the organisers of this event.  GAS will be there with Solar Telescopes on Day 1 Kid’s Day (April the 1st.).  SAGAS will also be present, assisting with Day 4 (Saturday April 4th) – Astronomy Day, and will be mounting a public Star Party in the grounds in the evening.

       The speakers for the day include the following:

 

Plenary Session – Prof Fred Taylor, Prof John Zarnacki, Prof David Southwood.

 

Astronomy Theme “She Is An Astronomer” – Prof Gillian Wright, Dr Helen Walker, Dr Clare Bretherton (RGO), Dr Patricia Shady (MSSL), Dr Maggie Alderin (EADS Astrium), Dr Lucy Rogers, Prof Paolo Caselli.

 

INTERNATIONAL YEAR OF ASTRONOMY 2009 HERSTMONCEUX SCIENCE CENTRE

 

       SAGAS is again hoping to provide support for running this event this year.  John Axtell sends the following letter:

 

 There are two main activities for which they are looking to SAGAS for knowledgeable resource.

 

One will be to take telescopes to support their Open Observing Evenings.  The other will need no scopes, just society members going along to family-oriented Activity Weekends to help youngsters to make simple telescopes out of a couple of cardboard tubes and simple lenses. The resulting scope can then be bought for £1 and taken away by its maker.  Those not sold will be broken down into components ready for the next similar event. In return for this help from SAGAS, Herstmonceux are making available their Gravity Well display available for use as part of our Rolling Road Show, which as you know will be made available on request to any SAGAS society to assist its IYA outreach event.  You may have seen this Gravity Well at the Herstmonceux stand at several past Astrofests, and is bound to provide a big “pull” (sorry, no pun intended), especially with youngsters – tomorrow’s members of your astronomical society.

Initially I am sending this just to those societies that I believe are within the catchment of the Observatory.  Of course Wealden AS will already be involved, as they have a special relationship with the Science Centre, but it is expected that plenty of support resource will be required.

The first of these Activity Weekends is fairly imminent – March 7th and 8th. I really should have got this request out earlier, but it’s snuck up on me – sorry!  After that the next one is April 4th & 5th.  This latter weekend coincides with the first of the telescope events – Friday 3rd and again Saturday 4th, when Moon-sketching will be among the evening activities.

Please contact your members to ask for their involvement.  Please could you email Sandra Voss s.voss@the-observatory.org at the Science Centre to confirm your involvement, and I’d appreciate it if you could CC to me so I can keep tabs on how we’re doing.

       Incidentally, there's no need to be concerned about whether or not CRB raises its head in these instances - there will be plenty of parents and Observatory Science Centre staff in attendance, so it's not an issue - which makes it easier for all involved.

Isn’t IYA2009 going to keep us busy!

 

Best wishes


John Axtell

Secretary, Southern Area Group of Astronomical Societies

 

SKY NOTES FOR MARCH

 

Planets

 

Mercury is not suitably placed for observation this month. It suffers a superior conjunction on March 31st. This is where Mercury, the Sun and the Earth are all pretty much in line with Mercury on the far side of the Sun.

 

Venus is still a brilliant object in the western evening sky although it will be lost in twilight before the end of the month. If you have binoculars have a look mid-month as you should be able to see the crescent phase which, by this time, will be very thin. Venus passes through an inferior conjunction on March 27th when it lies between the Sun and Earth.

 

Mars is not suitably placed for observation this month.

 

Jupiter at magnitude 2.0 is a morning object in the constellation of Capricornus (the Sea Goat) but is only visible towards the very end of the month.

 

Saturn at magnitude 0.5 still lies in the constellation of Leo, rising before sunset by the middle of the month. The diagram below indicates its position as shown by the cross hair and you will see that it has moved very little since last month.

 

 

 

Lunar Occultations

As usual in the table I’ve only included events for stars down to around magnitude 7.5 that occur before midnight. DD = disappearance at the dark limb and RD = re-appearance at the dark limb. Times are all GMT apart from the last two marked with a “B” for BST.

 

Mar

Time

Star

Mag.

Ph

PA °

2nd

19.26

SAO 75806

6.8

DD

49

2nd

20.51

SAO 75832

7.3

DD

34

2nd

21.03

SAO 75845

7.6

DD

109

3rd

22.54

SAO 76573

5.4

DD

72

5th

18.48

SAO 78250

7.6

DD

161

6th

21.38

SAO 79429

7.7

DD

146

6th

23.19

SAO 79489

6.6

DD

53

10th

18.50

SAO 118668

5.6

DD

74

10th

19.33

SAO 118668

5.6

RD

344

29th

20.00B

SAO 75671

6.8

DD

87

31st

22.48B

SAO 76970

7.6

DD

30

 

Phases of the Moon for March

 

First

Quarter

Full

Last Quarter

New

4th

11th

18th

26th

 

Comet Lulin

The position of Comet Lulin is shown for the first 3 days of March on the Leo map above as, by coincidence, it appears briefly in the same area of the sky as Saturn. The comet’s magnitude is around 6.3 on the first of the month so binoculars will be needed to see it. Its path up until the 17th is shown below although its magnitude is expected to have faded to 8.3 by then.

 

 

ISS

There are quite a few passes of the ISS as seen from Wadhurst in the latter half of this month that attain reasonable altitude and occur before midnight. The information given is for when the ISS is at maximum altitude, so it is best to look some minutes before this time. Full details of all passes can be found at: www.heavens-above.com 

 

Times are all GMT except for the last one marked with a “B” for BST.

 

Mar

Time

Mag

Alt°

Az.

18th

19.38

-2.0

48

SSE

19th

18.30

-1.0

26

SSE

19th

20.05

-2.4

83

SSW

20th

18.57

-2.0

53

SSE

21st

19.24

-2.4

89

S

22nd

19.52

-2.3

75

NNE

23rd

18.43

-2.3

87

N

23rd

20.19

-2.2

75

WNW

24th

19.11

-2.2

77

N

25th

19.38

-2.4

88

SSW

26th

18.29

-2.2

77

N

26th

20.05

-1.9

51

SSW

27th

18.56

-2.3

83

S

28th

19.23

-1.6

47

SSW

30th

19.42B

-1.3

43

SSW

 

Iridium Flares

The flares that I’ve listed are only the brightest, there are many more that are fainter, occur at lower altitudes and also after midnight. If you wish to see a complete list, go to www.heavens-above.com   All times are GMT.

 

Mar

Time

Mag

Alt°

Az.

7th

18.30

-2.0

55

N

8th

18.23

-5.0

57

N

9th

18.17

-3.0

58

N

12th

20.07

-2.0

23

N

13th

20.08

-2.0

22

N

15th

19.52

-7.0

29

N

15th

19.56

-3.0

27

N

16th

19.49

-7.0

29

N

17th

19.43

-7.0

31

N

18th

19.37

-2.0

33

N

26th

18.57

-2.0

46

N

27th

18.50

-4.0

48

N

28th

18.44

-6.0

49

N

 

The Night Sky

The evening sky is still dominated by Orion and his retinue, whilst Leo culminates at midnight by the end of the month. This means that Saturn is becoming easier to see. Arcturus (in Bootes) is rising in the north east, whilst Deneb (in Cygnus) may just be glimpsed very low down above the northern horizon. In Cancer, M44 an open cluster known as the Praesepe can be seen as a faint misty object. Comet Lulin is very close to it on March 6th.

 

At the last two meetings we have finished off the evening with brief talks on constellation recognition. There are star maps and instructions that go with these talks, copies of which will be available at meetings.

 

Don’t Forget

GMT ceases at 02.00 on Sunday March 29th.

 

NASA SPACE PLACE

 

Where did all these gadgets come from?!

 

Ion propulsion. Artificial intelligence. Hyper-spectral imagers. It sounds like science fiction, but all these technologies are now flying around the solar system on real-life NASA missions.

How did they get there? Answer: the New Millennium Program (NMP). NMP is a special NASA program that flight tests wild and far-out technologies. And if they pass the test, they can be used on real space missions.

The list of probes that have benefited from technologies incubated by NMP reads like the Who’s Who of cutting-edge space exploration: Spirit and Opportunity (the phenomenally successful rovers exploring Mars), the Spitzer Space Telescope, the New Horizons mission to Pluto, the Dawn asteroid-exploration mission, the comet-smashing probe Deep Impact, and others. Some missions were merely enhanced by NMP technologies; others would have been impossible without them.

”In order to assess the impact of NMP technologies, NASA has developed a scorecard to keep track of all the places our technologies are being used,” says New Millennium Program manager Christopher Stevens of the Jet Propulsion Laboratory.

For example, ion propulsion technology flight-tested on the NMP mission Deep Space 1, launched in October 1998, is now flying aboard the Dawn mission. Dawn will be the first probe to orbit an asteroid (Vesta) and then travel to and orbit a dwarf planet (Ceres). The highly efficient ion engine is vital to the success of the 3 billion mile, 8 year journey. The mission could not have been flown using conventional chemical propulsion; launching the enormous amount of fuel required would have broken the project’s budget. “Ion propulsion was the only practical way,” says Stevens.

In total, 10 technologies tested by Deep Space 1 have been adopted by more than 20 robotic probes. One, the Small Deep Space Transponder, has become the standard system for Earth communications for all deep-space missions.

And Deep Space 1 is just one of NMP’s missions. About a half-dozen others have flown or will fly, and their advanced technologies are only beginning to be adopted. That’s because it takes years to design probes that use these technologies, but Stevens says experience shows that “if you validate experimental technologies in space, and reduce the risk of using them, missions will pick them up.”

Stevens knew many of these technologies when they were just a glimmer in an engineer’s eye. Now they’re “all grown up” and flying around the solar system. It’s enough to make a program manager proud!

The results of all NMP's technology validations are online and the list is impressive:

nmp.nasa.gov/TECHNOLOGY/scorecard/scorecard_results.cfm

 

       For kids, the rhyming storybook, "Professor Starr's Dream Trip: Or, How a Little Technology Goes a Long Way" at:

spaceplace.nasa.gov/en/kids/nmp/starr

gives a scientist's perspective on the technology that makes possible the Dawn mission.

 

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

 

CONTACTS

 

Chairman      John Vale-Taylor

                                              pjvalet1@tiscali.co.uk

 

Treasurer             Mike Wyles                            01892 542863

                                              mike31@madasafish.com

 

Editor           Geoff Rathbone                       01959 524727

                                              geoff@rathbone007.fsnet.co.uk

 

Events                Phil Berry                                      01892 783544

                                              phil.berry@tiscali.co.uk

 

Sky Notes           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 April 2009 Newsletter should be with the Editor by 28th March 2009