Ordinary Meeting, 2003 October 29

The Great Perihelic Opposition of Mars 2003

Dr McKim began his presentation by asking the audience who had seen Mars with the naked eye in 2003: all hands were raised. Who had observed it telescopically? Most hands went up. But how many had actually sent their observations to the BAA? Just two hands were raised! The speaker asked all observers not to be modest and to send him their work: each contribution was part of the larger picture, and high-resolution CCD images were not the only type of observation wanted. The speaker demonstrated how telescopes of only 10 cm aperture had made valuable contributions during the current apparition.

Dr McKim said that it had been an exceptionally busy year, with a huge number of enquiries from members of the public, press, and BAA observers. The low altitude had deterred many UK observers, but it was now becoming much better placed despite the smaller disk diameter. A new Mars Section website had proven to be a great success. Referring to the reports of the observations appearing in the 2003 July, August and October Journals, together with records received up to the previous evening, Dr McKim described the thousands of CCD images and visual drawings that had been received. Compared with the year 2001, the apparition had been notable for the lack of large-scale dust activity, a regional storm in Hellas in July being the largest example to date. The shrinkage of the S. polar cap, lately very rapid, and the development of seasonal rifts and other features, together with the increase in 'white cloud' meteorology, was described in detail.

Standard Mars maps and Section members' observations illustrated the talk. There being no questions, the President asked the audience to return their thanks to the speaker.

Following prolonged applause for Dr McKim's lively and thorough account, Jonathan Shanklin was invited to make an announcement on behalf of the Comet Section. He urged members to observe Comet Encke, which was fast-brightening. Although professional CCD observers had returned faint magnitude estimates around 13-14, these were in part due to the combination of Encke's large diffuse appearance with the high resolving power of these instruments. The speaker's own observations with the Northumberland 12-inch refractor in Cambridge had yielded an estimate of mag 12.5, whilst binocular observers were commonly reporting that it appeared around mag 9.9.

The President adjourned the meeting until November 29 at the same venue.

-----

Dominic Ford

© 2003 Dominic Ford / The British Astronomical Association.