Mars in 2002–03 – Fourth interim report
The Section’s web site was heavily visited for the weeks around opposition, with some 200 visitors per day. The present very brief report continues from the October Journal, and concentrates upon visual work with smaller telescopes. It covers late spring and early summer in the martian southern hemisphere, from 2003 September 1 (Ls = 252 deg., D (disk diameter) = 25.0 arcsec, tilt = – 18 deg. S) to October 15 (Ls = 280 deg., D = 17.9 arcsec, tilt = – 21 deg. S).
The detailed appearance of the surface features at opposition is beautifully shown by the map made by Fattinanzi of Italy from his best CCD work (Figure 1). Visual observers also made the most of the large disk, those with smaller telescopes also achieving considerable success (Figures 2–3). Throughout the period under consideration the planet’s atmosphere has been largely dust-free, despite perihelion passage (Ls = 260 deg.) and the onset of southern summer solstice (Ls = 270 deg.). In early October there was a brightening of NW Hellas in red light, but nothing more. The continuing very rapid retreat of the SPC was a highlight of the immediate post-opposition period. Its regression and fragmentation were followed in exceptional detail (Figures 1, 2A, 2F, 3, 4). Atmospheric activity continued to increase, and by late September considerable morning cloud could be viewed at the sunrise terminator. Several observers continued to observe and to image the martian moons (Figure 4).
Figure 1 : Map from CCD work. A general map compiled by Christian Fattinanzi (Macerata, Italy, 250 mm refl.).
A computer-generated compilation made from the 15 best CCD images obtained from August 8 to September 22.
Figure 2 : Near-opposition drawings.
A Elisabeth Siegel (Malling, Denmark), August 10d 23h 35m, CML = 114 deg., 203 mm Schmidt–Cass., x267, INT+W25. Thyle Mons projecting from SPC. Phasis and Solis Lacus well seen.
B Michael Hendrie (Colchester, Essex), September 4d 22h 10m, CML = 231 deg., 152 mm OG. Wide Hesperia; SPC N. edge further south at this CML.
C Alan Heath (Long Eaton, Notts.), September 6d 21h 45m, CML = 308 deg., 254 mm refl., x278, W15. Bright evening cloud.
D P. Devadas (Madras, India), September 21d 14h 15m, CML = 324 deg., 360 mm refl., x300, various filters. Evening cloud; NPH; Edom light; Oxia Palus; well-developed Mare Serpentis, etc.
E Roy Panther (Walgrave, Northants.), August 30d 01h 55m, CML = 340 deg., 152 mm OG, x300; dark Mare Serpentis. Compare with the drawings of Adamoli and Devadas.
F Gianluigi Adamoli (Verona, Italy), August 22d 22h 55m, CML = 358 deg., 108 mm OG, x240. Note SPC detail, including Novus Mons on evening side. Dark Hellespontus.
|Figure 3 : The SPC near opposition. A drawing by Richard Baum (Chester), August 31d 21h 30m – 23h 00m, for CML = 265 deg., 150-mm Mak–Cass., x234. Impression derived from observation over an extended time interval. The cap had ragged edges and detached parts. On the f. side is an irregular Novus Mons.|
|Figure 4 : Mars and its moons. A drawing by Nicolas Biver (Ablis, France), August 24d 00h 17m, CML = 9 deg., 407 mm refl., x700. Both satellites to the left of Mars; Phobos closest to the planet.|
The next report
A further report will be written for the 2004 February Journal. To date, just over 100 observers have contributed a large amount of data, and deserve the Director’s sincere thanks. A complete list will appear later.
Richard McKim, Director