MEETINGS

 

FEBRUARY MEETING

 

        Phil Berry opened the meeting by announcing that Brian Mills is planning to lead an occultation evening as the moon passes through part of the Pleiades, although sad to relate now, the weather prevented the event taking place.

        Vectis Astronomical Society on the Isle of Wight is holding a Star Party from the 11th of March.  Any member is invited and for further information visit: www.iowstarparty.org/

        Two visits are being suggested this year.  The first is a visit to Herstmonceux to see some of their domes and telescopes, many not normally open to the public.  This visit is planned to take place on Saturday the 15th of May.  We would meet at 1000 with a talk at 1300.  The cost is £8-30 with concessions for Seniors and children, but if we can find 15 members interested in going, the cost falls to £7-70, Seniors £6-15 and children £5-90.  Members interested are invited to put their names in on a list that will be at the March meeting, or let any of the Committee members know.

        There is also the possibility of a visit to the Surrey Research Park to see the Surrey Satellite Technology facility near Guildford.  Arranged through SAGAS this would be on 10th July and take place from 1000 to 1630 and would include visits to see areas such as the Clean Room.  The cost would be about £10.  There will be more details nearer the time and members will be asked to indicate their interest.

        Then Phil introduced our speaker who is a regular presenter at the Planetarium in Greenwich Observatory grounds.  He is also well known to readers of Astronomy Now through his technical illustrations which leads to his subject this evening.

 

Astro Art

by Greg Smye-Rumsby

        Greg is the resident technical illustrator for Astronomy Now and with this in mind he introduced his talk about Astro Art, not just from an illustrator’s point of view but also including the critical eye of the astronomer.

        To begin with he posed the question; “What would a river look like on Mars or the moon?” and then looked at some artists impressions from long before man ever stood on the moon.

        The first picture we looked at was from “The Man in the Moone” by Francis Godwin, published in 1638.  Godwin imagined a moon with an atmosphere sufficient for a man to be carried aloft by birds and a sail over the rugged surface that supported trees and vegetation.

        We looked at the incredible drawings made by Galileo of craters and “seas” he observed on the Moon with the telescope he had made but which had a very narrow field of view and a magnificatioText Box:  n of only 7 times.  Greg explained how these observations began to change our understanding of space.

        From a popular magazine in 1954, Greg noted that in a picture of a moon landing site, the space vehicle had wings even with the lack of any atmosphere.  Despite these liberties some artists achieved some very accurate paintings and Greg illustrated this with a remarkable view of astronauts on Phobos looking at the planet Mars, then we were told that Velikovsky had suggested that Phobos could be an alien space ship.

        A little while ago, Wadhurst Astronomical Society had a talk about the space artist, Chesley Bonestall by Bob Seaney and now Greg recalled some of the artist’s remarkably accurate depictions of space scenes without ever having the knowledge we hold about space science today.

        Little was truly known about the thin atmosphere on Mars until man landed a camera on the planet and it was realised that the only thing we really knew was the colour of the only manmade thing the camera could see, and that was cables on the lander.  This enabled the colour of the sky to be corrected.

     Text Box: Mars from Phobos   Hergé’s Tintin had adventures on the Moon, but all Hergé could do was draw real earthly scenes because in the early 50s no-one knew what the moon’s surface looked like, hence he drew mountains with sharp profiles and as Greg said, we now know they are round.

        At this point Greg said he had been giving a talk at the Greenwich planetarium when he was asked by school children, how long it would take to die in open space.  He told them it would take about 2 seconds mainly because at such low pressure, the blood would boil.  The children were very impressed.

        Another space artist Greg referred to was Don Dixon, a prolific painter of pioneering futuristic and past space scenes with considerable imagination.  He had also been commissioned by NASA on a number of occasions.

        Don Davis imagined worlds in collision with speeds of about 60 kilometres a second.  The incredible amount of detail in his painting showed the imagined catastrophe that might take place.  Then Greg talked about the near Earth asteroid Apophis which is predicted to come close to the Earth in 2029 although recent calculations indicate that we would be in no danger this time round…

        As our knowledge of space science has progressed we were shown how space art had also progressed.

        In 1968, Stanley Kubrick’s film “2001 – A Space Odyssey” was released and much of this new knowledge helped form the background to the film, even though it was made before man had landed on the moon and again the mountains were shown as jagged instead of smooth.

        Another criticism of space art was the use of visible flame, and as Greg often repeated, there was still a lack of understanding of the science of space propulsion.

        One remarkable picture was an image taken during the Cassini mission to Saturn showing Prometheus, an inner satellite of the planet, seen with the rings in the background and even more surprising was a short black line on the edge of the inner rings which was explained as its shadow.

        An artist’s impression of a black hole can only rely on imagination and we looked at a few paintings, showing a black hole surrounded by the visual distortion of background stars.

        A few years ago Greg gave the Society an illustrated talk about looking for the remains of the Craig Telescope in Wandsworth.

        He now showed us a extraordinary visual reconstruction of the structure made had using CAD and then went on to show how he had created an image of a comet breaking up and throwing off water crystals using Photoshop, building the image up from many layers of other images he borrowed from where ever he could find them, such as the image of a waterfall, subtly used to show material being thrown off the comet.

        Greg gave his talk with his usual use of drama and amusement to the enjoyment of members.

        Following Greg’s talk, members made use of the clear sky.  We had previously found a dark spot behind Wadhurst Commemoration Hall where Brian Mills used his green laser to guide us round some of the features to be seen in the February night sky.

MARCH MEETING

 

        Wednesday 17th March 2010 – James Fradgley is from the Wessex Astronomical Society in Wimborne, Dorset and is also a Fellow of the Royal Astronomical Society.  This evening he gives a talk entitled “Life in the Universe”, looking at how life could develop and the conditions needed.

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

 

        Wednesday 19th May 2010 – Simon Allen gives a talk about “Space Elevators”.

 

        Wednesday 16th June 2010 – Society Open Evening when members are invited to bring telescope and other item of astronomical interest.

 

OTHER NEWS AND INFORMATION

       

VISIT BY UPLANDS STUDENTS

 

        On Tuesday the 26th of January, students from Uplands College visited Phil Berry’s home for an introduction to his observatory and to see what an amateur astronomer does.

        Twelve students attended with their tutor, Iain Pert and also present was Society member Brian Mills who brought his 5” refracting telescope.

        Also present was the Society’s Ian Reeves 4” refracting telescope and Phil set up his own Nexstar 5 Schmidt-Cassegrain instrument.

        They began with an introduction by Phil who described the differences between the telescopes; then in groups they were able to observe the Moon, Jupiter and Mars under the guidance of Brian Mills whilst others with Phil’s help were able to use the Ian Reeves 4” refractor and the Schmidt-Cassegrain Nexstar 5.

        The visitors were shown round the facilities of the observatory which evoked quite a lot of interest

        The sky was clear which meant that the temperature was as low as -4o C but Nicky provided very welcome mugs of drinking chocolate during their 1½ hour session.

        To finish, Phil and Brian invited any interested students to join one of our meetings, so we may well be able to welcome some of them some time.

 

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

50 CONSECUTIVE EDITION S OF ASTRONOMY NOW

 

        The Society has been offered 50 consecutive editions of Astronomy Now from November 1996 to December 2000.  Richard Shipp is looking for a good home for them.  If any member of the Society is interested in this unique collection, please contact Geoff Rathbone, the Newsletter Editor for contact details.

 

DEW PREVENTION

 

Dew Prevention

 

        A nice clear evening; clear skies forecast and a night of anticipated observing ahead.  Then the viewed image dims!  We discover dew has formed on the object lens or corrector plate in the case of a Schmidt Cassegrain telescope.  Wiping it away with a cloth is definitely to be discouraged for fear of marking or even damaging permanently the lens coating.

        It may be asking a lot, but prevention is better than cure.

        Whenever there is moisture in the air and the air either falls in temperature or pressure, it cannot hold as much water and it condenses out as water droplets at what is called the Dew Point.

        Before we begin the evening’s viewing, we leave the telescope at the surrounding temperature in the hope of avoiding this but any heat in the upper surfaces is radiated out into space.  Dew doesn’t fall from the sky it forms when the saturated air come into contact with a cooler surface.

        To some extent, a Newtonian telescope is protected because the mirror surface is at the far end of a tube, although the problem could exist if the sides are open.  A cloth covering the length of the open tube can help here.

        Telescopes in observatories are also protected because the air inside is usually drier and the outer surface of the dome gets the bulk of the condensation.

        Perhaps the cheapest method of dealing with the problem is to make one’s own Dew Shield.  This is a shield that extends beyond the front of the telescope by at least 1½ times the diameter of the front lens.  It also pays to include about a 3o flare-out to prevent vignetting.

        Other methods of reducing the effect use such things as hair driers, but this usually cures the problem for about five minutes.

        A more practical method is to use heated strips round the outside of the telescope, often called “dew zappers”.  They work off 12 volts and when the strip is positioned just behind the lens or corrector plate they are quite efficient.  Some observers use the strips even when there is no dew expected, and say they believe it does improve the overall viewing experience.

Text Box:          Another problem can be dew forming on the lens of the eyepiece.  This can be reduced by using rubber eye caps which also enables the eye to fit snugly, keeping out stray light.

        Storing a telescope necessitates great care to avoid putting the telescope away with any hint of moisture.  All signs of dew must be removed and it is sometimes a good idea to leave the eyepiece blanking plate off to allow air to circulate. but the aperture should then be covered with cloth to prevent access to spiders which could monsters in space!

        Some telescope owners store their telescopes with a bag of about ¾ of a pound of silica gel which they dry out in a low heat perhaps once or twice a month.

 

Geoff Rathbone

 

 

Text Box: Positioning the Dew Zapper heated strip

SKY NOTES FOR MARCH

 

 

Planets

 

Mercury experiences a superior conjunction on the 14th March when it passes behind the Sun as seen from Earth. It is then to the east of the Sun making it an evening object. By the end of the month it will be visible in the west (in fact just north of west) after sunset. The visibility of Mercury improves during the first week or so of April giving us the most favourable evening apparition of 2010. Please remember that if you are sweeping for Mercury with binoculars you must wait until the Sun has set.

 

Venus is an evening object at magnitude -3.8 (and brightening) by the middle of the month when it sets just over an hour after the Sun. Telescopically its phase is gibbous although the disk is comparatively small.

 

Mars is a brilliant evening object at magnitude -0.2 high in the sky in the constellation of Cancer and remaining on view all night, setting at around 05.00hrs. Its position is shown in the diagram but it is so obviously orange/red that is unmistakable, although the Earth is gradually pulling away meaning that Mars is becoming smaller and fainter.

 

Jupiter was in conjunction with the Sun on 28th February and is therefore not yet observable to us as a morning object.

 

Saturn lies in the constellation of Virgo (see map above) at magnitude +0.5 and by the middle of the month rises at 18.00hrs. The planet reaches opposition on the 22nd of March meaning that the Sun, Earth and Saturn are all in a straight line on the same side of the Sun with the Earth in the middle.

 

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. Times are all GMT.

 

 

Mar.

Time

Star

Mag.

Ph

PA °

19th

20.42

SAO 93062

5.7

DD

65

20th

21.37

SAO 76043

6.7

DD

138

22nd

20.24

SAO 77252

7.0

DD

139

26th

21.00

SAO 98627

5.0

DD

49

27th

18.29

SAO 118271

6.5

DD

89

 

Phases of the Moon for March

 

Last ¼

New

First ¼

Full

7th

15th

23rd

30th

 

 

ISS

There are so many evening passes of the ISS this month that I have only included those of magnitude -2 in brightness or above. Please remember that the times shown below are for when the ISS is at its maximum elevation, so you should start looking a few minutes beforehand. Details of all passes can be found at www.heavens-above.com Times are all GMT.

 

Mar.

Mag

Time

Alt°

Az.

5th

-2.0

19.09

24

SSE

6th

-3.0

19.31

47

S

7th

-2.6

19.52

48

WSW

8th

-2.9

18.40

45

SSE

9th

-3.5

19.01

80

SSE

10th

-3.4

19.23

78

N

11th

-3.4

18.10

77

SSE

11th

-3.5

19.45

79

N

12th

-3.3

18.32

79

NNW

12th

-2.4

20.06

45

W

13th

-3.4

18.53

78

N

14th

-3.4

19.15

81

SSW

15th

-2.8

19.36

47

SSW

16th

-3.3

18.23

83

SSW

17th

-2.7

18.44

49

SSW

 

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 with the exception of the three indicated.  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.

 

Mar

Time

Mag

Alt°

Az.

 

2nd

18.09

-4

52

S

 

16th

18.47

-6

61

SSE

 

21st

18.26

-8

62

S

 

21st

20.06

-4

53

E

 

24th

19.52

-6

56

ESE

 

29th

20.31

-6

63

ESE

BST

30th

22.01

-5

37

ENE

BST

31st

21.54

-3

38

ENE

BST

 

 

Advance Warning for April

The April Lyrids are active from the 19th to the 25th with maximum on the 22nd.

 

Note: British Summer Time begins on Sunday March 28th at 02.00hrs.

 

Brian Mills

 

NASA’S SPACE PLACE

 

Flipping the Lights on Cosmic Darkness

 

        Exploring the universe is a bit like groping around a dark room. Aside from the occasional pinprick of starlight, most objects lurk in pitch darkness. But with the recent launch of the largest-ever infrared space telescope, it's like someone walked into the room and flipped on the lights.

        Suddenly, those dark spaces between stars don’t appear quite so empty. Reflected in the Herschel Space Observatory's 3.5-meter primary mirror, astronomers can now see colder, darker celestial objects than ever before—from the faint outer arms of distant galaxies to the stealthy “dark asteroids” of our own solar system.

        Many celestial objects are too cold to emit visible light, but they do shine at much longer infrared wavelengths. And Herschel can observe much longer infrared wavelengths than any space telescope before (up to 672 microns). Herschel also has 16 times the collecting area, and hence 16 times better resolution, than previous infrared space telescopes. That lets it resolve details with unprecedented clarity. Together, these abilities open a new window onto the universe.

        ”The sky looks much more crowded when you look in infrared wavelengths,” says George Helou, director of the NASA Herschel Science Centre at Caltech. “We can't observe the infrared universe from the ground because our atmosphere blocks infrared light, and emits infrared itself. Once you get above the atmosphere, all of this goes away and suddenly you can look without obstruction.”

        Herschel launched in May from the Guiana Space Centre in French Guiana aboard a European Space Agency Ariane 5 rocket. Since then, it has expanded the number of distant galaxies observed at far infrared wavelengths from a few hundred to more than 28,000. And with the instrument testing and system check-out phases finally completed, the discoveries are only now beginning.

        Beyond simply imaging these dark objects, Herschel can identify the presence of chemicals such as carbon monoxide and water based on their spectral fingerprints. “We will be able to decipher the chemistry of what's going on during the beginnings of star formation, in the discs of dust and gas that form planets, and in the lingering aftermath of stellar explosions,” Helou says.

        And those are just the expected things. Who knows what unexpected discoveries may come from “flipping on the lights?” Helou says “we can't wait to find out.”

        Herschel is a European Space Agency mission, with science instruments provided by a consortium of European-led institutes and with important participation by NASA. See the ESA Herschel site at:

sci.esa.int/science-e/www/area/index.cfm?fareaid=16

Also, see the NASA sites at:

http://herschel.jpl.nasa.gov

 www.herschel.caltech.edu

and

www.nasa.gov/mission_pages/herschel

Kids can learn about infrared light by browsing through the Infrared Photo Album at The Space Place, spaceplace.nasa.gov/en/kids/sirtf1/sirtf_action.shtml.

 

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

The Herschel Space Observatory has 3.5-meter primary mirror, allowing astronomers to see colder, darker celestial objects than ever before.

 

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 April 2010 Newsletter should be with the Editor by March 28th 2010