Meeting Reports for 2010
Here you'll find brief reports of our meetings in 2010. In these we try to include any web links or other pointers to further information that were provided by the speaker at the meeting. If you were at one of our meetings and would like to correct or expand the report relating to it then please email our webmaster.

Members Evening - April 22nd Print E-mail
Our April meeting was a Members Evening, with two members giving us talks about things that interested them. Hugh Alford gave us a talk about the Renaissance philosopher Giordano Bruno, who was convicted by the Roman Inquisition of heresy and burned at the stake in February 1600, at least partly because of his beliefs about the infinite nature of the universe. Mike McRoberts gave us a talk about his Earthshine 1 high-altitude balloon project, which included video of the Orion 1 balloon launched last month.
 
Meteor Echoes - March 26th Print E-mail
At our March meeting Allan Bell gave us a talk about Meteor Echoes, in which he explained how radio (and radar) could be used to watch for meteors, and how meteor trails could be put to other uses. Meteors produce trails of ionised gas which may persist for several minutes, and these will reflect radio signals if the geometry is good. Ideally, a powerful VHF transmitter needs to be located outside line-of-sight reception distance, so that the receiving station will only receive a signal when a meteor trail is in a suitable location. In the past a transmitter in Gdansk transmitting on 70MHz served well, but while it is still used at times, it no longer transmits all night. A VHF beacon GB3ANG transmits continuously from Scotland, which satisfies the over-the-horizon requirement for observers in the South of England, but it only emits ten watts, so a large antenna is needed if it is to be used for meteor observations. In the USA meteor observers have used VHF TV and NASA satellite radar system signals for meteor observations. Even if the geometry is good, not all signals come via reflection from meteor trails. Atmospheric and Ionospheric conditions can also give over-the-horizon reception of VHF signals, and if a transmitter is strong enough then reflections off satellites can also be heard. Allan rounded off his talk by explaining that meteor echoes can be used for more than simply counting meteors. They can also be used to hold short over-the-horizon conversations on VHR radio, and there are a number of scientific stations using dedicated transmitters and arrays of receivers to determine the atmospheric conditions at meteor altitude much more economically than by using sounding rockets.
 
AGM and President's Address - February 26th Print E-mail

The Society Annual General Meeting was held at BEECHE, High Elms. After the normal business including officers' reports and the election of the committee for 2010, our President Gilbert Satterthwaite gave us a second installment of his memories:

Bobb Webber writes: Gilbert presented the second part of his occasional series regarding his career at the Royal Greenwich Observatory and Herstmonceux. This part, called Greenwich to Herstmonceux, reviewed his move between the two sites and an overview of his new Herstmonceux home.

Gilbert had a month to train on the Transit Circle at Greenwich, at the end of which he took the last published observation on 30th March 1954, prior to his departure to Herstmonceux in July 1954. The various RGO departments decanted to Herstmonceux over a ten year period, with the solar observatory being operational back in 1948/9. He noted that the solar team took spectroheliographs at both Greenwich and Herstmonceux with the same instruments on the same day as their move to the country!

What Gilbert found at Herstmonceux was a 1540s brick built moated castle set in 380 acres of Sussex countryside. The building had fallen into disrepair back in the 1600s and been twice refurbished in the twentieth century.

Environmental concerns at Greenwich meant that a new home had to be found for the working observatory, and a decision to move to Herstmonceux was finally taken in 1939, though of course, implementation was delayed by the war. When Gilbert got there, as well as the castle, there were grouped huts which included two for the male employees, the previously mentioned solar observatory (which was largely underground), the Meridian instrument (in the Spencer Jones group), the Reversible Transit Circle, the Photographic Zenith Tube (complete with mercury mirror, for accurate time and position measurements), and the Equatorial Group (in domes imaginatively named "A" to "F"). Gilbert also mentioned some of the more recent additions, including the sundial and the statue of the first Astronomer Royal, John Flamsteed, which was installed in the early seventies.

The Castle itself housed the AR (initially Sir Harold Spencer Jones KBE) in one corner, the women employees in the old servants' quarters at the top of the building, the Library and public function rooms, and the offices of several of the astronomical sections.The latter included the Right Ascension and Zenith Distance rooms - a hang-over from Greenwich! Indeed, Gilbert oversaw the first main computer installation (with space to suit!) and the consequent change from manual computation of results to the gradual automation and computerisation of the same. Some change...

We await the next installment!

 
Mars Exploration - January 28th Print E-mail

The speaker at our January meeting was Doug Ellison. He gave us a fascinating talk about the exploration of Mars, with particular emphasis on the various missions sent there in the last twenty years or so. A large part of his talk was about the astonishing rover missions Spirit and Opportunity, including the very latest available images, but he also covered the missions that led up to them, and told us something about plans for further missions, with particular emphasis on the large rover currently being prepared at JPL.

 
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