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Heavens Above

On the 18th July club member Howard Mann stepped in, at only a few days notice, to fill in for a speaker who could not make it.  Howard chose one of his favourite hobbies – Astronomy – and had compiled a comprehensive talk covering the very latest developments in space exploration.  In fact he and his wife Margaret had attended a day of public lectures at the Royal Astronomical Society (the RAS) the previous week, and he managed to condense their four hours into just over half an hour of PowerPoint presentation.  Fortunately for the audience he had substituted some amazing photographs obtained from the European Space Agency and NASA web sites for much of the associated physics!

Club member Howard Mann presenting his talk to the Club

 The source lectures had been presented by eminent scientists including Prof John Zarnecki (current President of the RAS) and Prof Gerry Gilmore of Cambridge, and the accomplished engineer Abigail Hutty who is lead structural engineer for the Mars ExoRover being built at Airbus Defence & Space (formerly Astrium) at Stevenage and has recently taken on the role of Delivery Manager for the project.

 Howard gave details of the Cassini-Huygens mission to Saturn which launched in 1997, had to swing past Venus, then Earth, then Venus again, and finally Jupiter to use their gravitational pull to boost it to the speed necessary to reach the outer solar system and arrive at Saturn in 2004.  It dropped a lander craft onto Saturn’s largest moon Titan and has since been photographing and analysing the Saturn system.  Man’s knowledge of this “gas giant”, its rings and many of its 52 moons has been virtually rewritten by the results.  It is in the news again soon as it is completing its “grand finale”, twenty two final orbits swooping through the 1000 or so mile gap between the planet and its rings.  It was interesting to note that these long duration missions – more than 10 years in design and then 20 years in space – mean that the technology seems curiously antique when the results come in.  Cassini (designed in the 1980’s) has 2Gb of memory and a 1M pixel camera sensor: The current iPhone7 has up to 256Gb memory and a 12M pixel camera!

Club members James Knight (left) Bob Knowles and Peter Aspinall (right) listening totally enthralled by Howard's erudite presentation on latest developments in space

 Another major mission was described, the Gaia spacecraft, launched in 2013:  Since 2014 it has been orbiting the sun in the shadow of the Earth some 93 million miles beyond our Earth orbit, measuring the distances and motions and nature of the stars in our local Milky Way Galaxy.  It is the first project to produce a 3D map of a 30,000 light year wide patch of our 100,000 light year wide galaxy.  It was intended to measure 1 billion stars – but has so far measured about 2.5 billion!  It is another European project, with all the data being processed in Cambridge.

By the way, the accuracy of its photometry is such that, whereas previous equipment could measure, from the Earth, say the height of a man standing on the Moon, Gaia could accurately measure the size of his thumb nail...

 The Mars ExoRover mission currently being built at Stevenage is due to launch in 2020.  This rover will land in a new region on Mars and continue the search for any evidence of historic living organisms.  It will use ground radar to select areas to drill down 2m below the surface, beyond the degrading effects of UV and other radiation, and then analyse the samples.  A prime consideration on such landing missions is that we do not contaminate the planet with Earth organisms: to this end there is international agreement that spacecraft are sterilised to contain a maximum of 30 organisms at launch (which compares with probably a billion on the sponge in your kitchen sink!!

 Other areas that Howard covered included the search for exoplanets (planets orbiting stars elsewhere in our galaxy, not those orbiting our Sun in our own solar system).  Although suspected, it is only 20 years since the first was confirmed, but we now know of 2,000 with thousands more candidates.  Another lecture covered was that by the photographer who coached British astronaut Tim Peake, both before and during his mission on the International Space Station:  Howard passed round Tim Peake’s published space photo album.

 

 

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