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December 15th |
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This is traditionally an evening with a festive theme, with a little more than the usual refreshments. After the coffee break Tony Sizer marshalled us into teams and presented us with a quiz including rounds on observatories, Messier objects, space probes, satellites, and music with astronomical connections. The Old Peculier team romped into the lead from the start, but were widely considered to have had an unfair advantage, even if they did have some strange ideas as to the wherabouts of certain craters. Far greater acclaim was accorded to The Tea Ladies. At the end of the evening at least a few members found their way to the Change of Horses in time to round off an enjoyable evening. |
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November 24th |
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This evening the usual notices included some brief reports from the recent Deep Sky Camp. After the coffee break Helen Walker gave us a talk about Exploring the Planets using Satellites. She has been involved with various missions, and is currently working on Mars Express, which carried the unfortunate Beagle2 to Mars. Mars Express has been much more successful, and continues to return interesting results, some of which have prompted scientists to re-examine images returned by previous missions including Viking, to look for real features rather than faces and pyramids. She also talked about international co-operation, giving the current Mars rovers and orbiters, and the Cassini/Huygens mission as examples of successful co-operative missions. Mars Express is used to relay some data from Spirit and Opportunity, and Cassini carried Huygens to Titan, and then relayed its data back to Earth. Other current ESA missions like Rosetta, SMART-1, and Venus Express promise more interesting discoveries in years to come. We look forward to hearing about them in due course. |
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October 27th |
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This Members Evening started with a short reminiscence about the Society's past from our president Gilbert Satterthwaite. After coffee, Tony Buick showed us a selection of his astro-photos. Some were of his favourite subject, the Moon, but he also included photos of other subjects. Next, David Price presented a brief explanation of the kinematic effects of Einstein's theory of Special Relativity. Last, Mike McRoberts gave a talk about the basic operation of his new astro-imaging equipment, including some recorded sessions to illustrate various stages in the process. He concluded his talk by showing us some of of his recent images. |
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Ken Budd Memorial Lecture - Saturday 15th October 2005 |
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 Saturday evening saw members gathering at Newstead Wood School to celebrate the Society's 25th Anniversary and to host the third public Ken Budd Memorial Lecture. A fine exhibition of images, posters, telescopes and slide-shows was on display.
Professor Paul Murdin of the Institute of Astronomy, Cambridge, delivered the lecture; a most interesting account about the history of the Paris Meridian with the title "The Metre and the Shape of the Earth". The Meridian was first surveyed in the 17th century as part of an effort to map France accurately. The original baseline is still present on modern maps, having turned first into a track, then a road and now a six-lane motorway. Several colourful characters were involved, both in the survey effort, and in subsequent investigations which aimed to determine the shape of the Earth. Arguably the most colourful, especially if his own accounts of his adventures are to be believed, was Francois Arago. A series of bronze discs bearing his name now mark the line of the Meridian through Paris. The Greenwich Meridian was adopted as the Earth's prime meridian at the Washington Conference in 1884, but the Paris Meridian still has a place in the history of navigation and geodesy. After a break for refreshments and a quick look at the Moon, and a short session of questions arising from the lecture, the brief closing speeches and vote of thanks brought a most enjoyable and informative evening to a close. |
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September 22nd |
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Jerry Workman of Loughton Astronomical Society gave us a profusely illustrated account of some of the results returned by The Cassini Mission. He first showed us the kinds of images returned by Pioneer and Voyager, and then went on to show us many images from Cassini and Huygens, of Saturn's atmosphere, its rings, and its many moons, including Titan, which was the target of the Huygens probe. As Cassini continues to return data, we expect to see many more startling sights and surprising discoveries in the future. |
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August 25th |
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Tony Sizer of the Orpington Astronomical Society and the Royal Observatory, Greenwich, gave us an informative talk about "The Hertzsprung-Russell Diagram". This diagram was developed independantly by Hertzsprung and Russell as a way of categorising stars based on two directly-measurable properties, surface temperature and absolute brightness. After some introductory explanation of the ways these properties are measured and how the appropriate scales work, Tony went on to show how information about stars could be deduced from their relative positions on the diagram. These relationships, when combined with information we know about our own Sun and its place in the diagram, allow things like stellar diameters to be estimated. By taking plots of stars of the same age from suitable clusters it is possible to chart the course of at least some stellar evolution. By the end of the talk it was clear that the diagram provides a firm base upon which theories about the birth, development and death of stars could be built. |
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July 28th |
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Allan Bell of the Loughton Astronomical Society gave us a talk with the title "The Gravity Zoo". In it he talked about tides and stellar evolution; both processes in which gravity plays a significant role. He explained why the influences of the Sun and Moon on the Earth's oceans and seas lead to most coasts experiencing two tides a day, and why the Sun's influence appears the weaker despite its much greater "pull". He then briefly described some of the tidal effects seen on other celestial bodies like Jupiter's moon Io, and Saturn's rings. He then went on to explain some of the processes involved in stellar evolution, and gravity's role in them. Along the way he illustrated points with animated slides, and towards the end, with recordings of pulsars. |
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June 23rd |
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Alan Longstaff's talk "What are Terrestrial Planets made of?" began with a short lesson in basic geology; it's as well to know a bit about the way the Earth has formed first. Alan explained the structure of the Earth from its core to its crust, and described some of the processes involved in plate tectonics and the formation of ocean floor, volcanos and mountain ranges. He pointed out the role that Earth's abundant water has had to play, and how it led to a planet with unique features. The Moon's formation led to it having a crust mostly made of anorthosite. Meterorite impacts allowed basaltic rocks to flow from below that crust to form the "seas". Little is known about Mercury, but in some ways it's the Moon's opposite, apparently having a large metallic core, and a surface composition more like the Earth's mantle than the Moon's crust. Venus is also somewhat mysterious, but it does have a great many volcanos, and some impact craters. The distribution of the volcanos suggests that it, like Earth, has hot convecting plumes in its mantle, but unlike Earth it does not have plate-tectonic features. Mars was Alan's final subject. It too shows evidence of having mantle plumes, but there remains some doubt about the role water has played in its formation. Recently the NASA rovers Spirit and Opportunity have found minerals that are most likely to have formed in the presence of liquid water. However, some of them would also have been destroyed if they'd been in the presence of liquid water for an extended period of time. It is possible that liquid water was only present for very brief periods of time, maybe only a few weeks or months. Alan left us with the impression that, while much is known, there's a lot more yet to be discovered about the terrestrial planets. |
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May 26th |
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Neil Bone, director of the British Astronomical Association's Meteor Section came to talk to us about "Meteors". His talk included anecdotes about deck chairs, cameras, cloudy nights, random luck, as well as photographs of meteors, fireballs, comets, noctilucent clouds and Concorde's after-burner contrail. He rounded off the talk with some fascinating details about the results that have been derived from the systematically recorded observations of thousands of observers, with particular reference to the Leonid meteor maxima between 1996 and 2001. |
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April 28th |
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Our spring Members Evening was the occasion for three talks. The first, by Tony Buick, was an update on his earlier talk "My Camera and the Moon", and included some photos of other astronomical objects as well as plento of the moon. Next, Tony Sizer showed us some of the images and that were taken during the Society's last Evening with the Stars at Greenwich. Of particular note were imgaes of Saturn's satellites. Those who made it to the session clearly enjoyed a fantastic hour of observing. The last talk of the evening, by Chris Suddell, took a light-hearted look at the plausibility of some of the ideas behind a popular Sci-fi TV series. |
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March 24th |
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Our newest Honorary member, Greg Smye-Rumsby gave this evening's talk; a retrospective look at observations and explorations, called "Mars Revisited". His illustrations ranged from drawings by Antoniadi and Lowell, through to the latest images from the various rovers, landers and orbiters currently exploring the planet. He talked about many of the surprises Mars has produced, as each generation of observers interpreted their latest results and found they had to discard the previous generation's certainties. We now know a great deal more about Mars than Antoniadi and Lowell, but there are still plenty of answers waiting to be discovered. |
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February 24th |
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On the occasion of the Society's Annual General Meeting our chairman Paul Whitmarsh gave us a short address on the highlights of the Society's year just past, and then, after coffee, rounded the evening off with an illustrated talk about a trip he made twenty years ago to La Palma and Tenerife to see Comet Halley. In keeping with the retro theme, all his illustrations were on 35mm slides, and the views of the Milky Way and other star-fields were fantastic. In one night's observing he also managed to catch all the naked-eye planets, including Uranus (at magnitude 5.5). |
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January 27th |
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Robert Massey from the Royal Observatory , Greenwich, gave a talk called "Imaging the Universe". Since telescopes were first turned to the heavens they've been used to make discoveries. As larger and better telescopes were made, so the nature of the discoveries changed, but eventually limits were reached. For 40 years the 200-inch at Palomar was the best instrument available. Then, in 1990, the Hubble Space Telescope changed everything. The idea of putting a telescope in space, above all the degradation and distortion caused by the Earth's atmosphere, had been proposed by Lyman Spitzer nearly 40 years earlier. The HST's 2.4 metre mirror, while much smaller than Palomar's, was also more precisely made (even the spherical aberation was precise), and it has therefore been able to look much deeper into the Universe's past than any previous optical telescope. The HST has helped to determine the age of the Universe, and has also provided excellent images of objects nearer Earth, including the outer planets. It is the only instrument that has so far been able to reveal any detail at all on Pluto, and its ability to monitor the planets when there are no space probes visiting them has led to discoveries about Uranus's seasons and Neptune's weather. It has shown us images of events within (and near) our own galaxy that have helped confirm theories on planetary system formation. Other images have led to greater understanding of pulsars, supernovae, gamma-ray bursts, super-giant stars, and very strange old galaxies. Sadly, it seems that the HST will not last much longer, but there have also been developments in ground-based telescope design that mean some of the work the HST has done can be continued using telescopes on Earth. The significant developments have been in making larger mirrors and in adaptive optics which can compensate for the distortion caused by the Earth's atmosphere. Work is also being done on optical interferometry, which holds the promise of resolution sufficient to resolve planets circling nearby stars. We can expect many more exciting discoveries to be made using images from these new telescopes in the years to come. |
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