Friday, 6 March 2015

March Meeting - Satellite Altimetry

Thanks to Kim for his work on this months meeting.

The meeting began as usual with a "What's Up " item given this month by Jim, the Lunar phases and planetary prospects were covered as was the seasonal sky with the advent of the summer constellations now swinging into the sky during the early hours.

Of the Planets, though several are on display, it is really only Jupiter and Venus that show well, the rest are either setting early, or too low to show much detail.

After Jim's presentation and the obligatory tea and biscuits, the group settled down in some anticipation of the main event, a talk on Satellite Altimetry by Prof Phillipa Berry. 

I doubt if many had much idea what to expect, even less could figure the application of the discipline, but after a rather complex start, Philippa started to make clear the purpose of this rather extensive space program, and it's applications were surprising and varied, being able to detect ocean plate ridges due to the variance of the earth's gravity, which in turn causes a noticeable variation in the mean sea level. Also topography, and rising water levels, measuring various lakes and even river systems, the variety and detail possible with this technology was remarkable.


In the solar system itself microwave altimetry has been used to study Titan, and due to the nature of the Methane/Ethane sea, the returns were able to see the depth of the shallower parts of the hydrocarbon lake (we learned that this was not possible with water due to the ionic bond nature of water molecules, but the co-valent bonding in Methane allowed some penetration and return, thus the depth reading was possible) this was quite a discovery.
Much finer details were covered during the discourse, but I have neither the ability nor the memory to include them in this report, suffice to say, the talk was a fascinating insight into the whole arena of this particular area of research.

The evening did not, as is more usual, end there, we were also treated to a minor fashion event as our Secretary, Rob Woodman, provocatively modelled the new polo shirts that are now available to order, along with some fleece and hoody style over garments.

All in all, a fine meeting in which we all learned something.