Our guest speaker for the final meeting of 2012 was our Treasurer, Eric McCrum, who presented us with a slide show and talk entitled “The night sky”.

By way of introduction we were reminded that, as a natural science, star gazing would have been one of the earliest sources of wonder to ancient peoples as they gazed at the night skies and became familiar with particular star groupings and noticed the wanderings of planets. The progress of our understanding of space owes much to the early works of Copernicus and especially Galileo (1564-1642), whose sketches of his observations and publications led to confrontation between scientific observations and the dictates of the established church at the time. Galileo, with his self-fashioned telescope, was one of the early observers of the moon, but his other observations on planets, moons and the sun were many, and included work on Jupiter’s moons.

We viewed an excellent collection of slides showing images of planets in our solar system, nebulae in Taurus, Sagittarius and Cygnus, various nebulae beyond the Milky Way, numerous galaxies (including spiral and elliptical types) and super novae remnants. Images were from the more recent space exploratory ventures including the Mariner probe (1994) and Hubble space telescope. Many of the images can be seen on web sites featuring the Hubble space telescope (HST), originally launched by NASA’s space shuttle in 1990. The telescope has a 2.4 m aperture. It is in low Earth orbit, is outside the distortion of Earth’s atmosphere, allowing for sharp images with almost no background light. The main instruments on the HST examine light spectroscopically in the near ultraviolet, visible and near infrared ranges and provide data on the chemistry of distant objects. Early in the operation of the HST problems were discovered with the main mirror, but these were corrected by a manned servicing mission in 1993. Since then observations have provided many important breakthroughs in astrophysics. A final servicing mission was completed in 2009 and the HST is expected to function until at least 2013.  

Eric also demonstrated, with contrasted views of the night skies, how dust pollution limits the spectacle of terrestrial star gazing. His distinctive and enthusiastic style served well to remind his audience of the great strides made in recent years of space exploration work that show beautiful images of the night sky within and beyond our Solar System.

Susan Stocklmayer