Ewen Whitaker: The Lunar South Polar Regions (1954)(glossary entry)
Early maps and descriptions of the Moon's polar regions are filled with contradictions, and the IAU's identification of polar features in their 1935 nomenclature was ambiguous. In the absence of any better information, the charts published in Ewen Whitaker's 1954 article have become the de-facto standard for naming the polar peaks. In addition to attempting to resolve the identity of the then-current IAU-named features, Whitaker added six possibly new peaks of his own (denoted M1..M6), and eight "rings" (craters in the modern terminology).
- This article is available on-line (905 kb PDF) in Chuck Wood's Lunar Classics collection.
- Additional scans of Whitaker's maps, separate and combined can be found on the website of Stefan Lammel.
- A 150 dpi scan of Whitaker's two maps, as well as a 1967 map by Harold Hill, can be found on a webpage by Richard P. Wilds.
- Whitaker's results are based on a three-year study from 1951-1954.
- The charts are tracings from photographs, supplemented with additional detail secured by visual observations and the study of other photographs. The key photograph for Chart A (showing the western side of the pole) was taken with the 36-inch reflector of the Greenwich Observatory on December 11, 1951 at 20:59 UT (sub-observer point 4.28 E/ 6.11 S). It is reproduced in the article. The key photograph for Chart B (showing the eastern side of the pole) was taken on January 22, 1953 at an unspecified time (and with unspecified instrumentation). It is not shown, but if it was taken from Greenwich at ~19:00 UT the sub-observer point would have been 6.30°E/ 6.36°S.
- The single uppercase Latin letters (lettered craters) and lowercase Greek Letters (peaks) represent Whitaker's interpretation of the meaning of IAU feature names appearing in Named Lunar Formations (1935). The elongated feature labeled "S. 334", near the right edge of Chart A, is a reference to rille No. 334 in Julius Schmidt's 1866 catalog. The letter-number combinations starting with "R" and "M" are Whitaker's notation for previously unnamed craters (Rings or ring-plains) and Mountains.
- The names Scott and Drygalski had been introduced by Arthur and Fauth, but were not part of the official IAU nomenclature at the time of Whitaker's work. They became official ten years later, when Arthur, in IAU Transactions XIIB, listed them as new names used in the Rectified Lunar Atlas. Another unofficial name Whitaker used ("Cortes" of Wilkins and Moore) never became official. That crater is now Ganswindt
- Many of Whitaker's unnamed rings have since received official IAU names:
- Whitaker's peaks M1, M3, M4 and M5 are easy to recognize on modern photographs. M2 and M6 are much less conspicuous. None of these peaks have current IAU names, although some may have had names in the past.
- The small unlabeled crater that Whitaker shows straddling the prime meridian (the line of zero longitude) in his Chart A, just below the Moon's South Pole and just above his Malapert Alpha, might at first glance appear to be the polar crater Shackleton, but in fact it represents a still unnamed smaller ring-shaped pattern of light connected by a ridge to Shoemaker (Whitaker's R4). It (and the ridge) are readily visible on modern photos. The somewhat larger Shackleton is to its upper left, but Whitaker was apparently unable to recognize it as a crater. Instead he saw it as two overlapping ridges which he depicts to the immediate left of the point he labels "S. Pole".
- Although they have come to be generally accepted, Whitaker's identifications of the IAU-named features are not always consistent with earlier descriptions of the Moon's south polar regions (a task that, due to the inconsistencies in those descriptions, is probably impossible to achieve). For example, Neison (from whose lettering the 1935 IAU nomenclature was directly derived) left an 1880 description (which Whitaker may have been unaware of) making clear that his Leibnitz Alpha was a "double-peaked mountain" beyond the mean limb. Since the date of Neison's observation is given, it is now clear that his Leibnitz Alpha (and presumably the IAU's) consisted of what Whitaker called M4 and M5, seen overlapping in projection. Similarly, Whitaker's Malapert Alpha sounds like Neison's description of the south wall of Malapert, with Neison's Malapert Alpha described as a wedge-shaped mountain to the west (Whitaker's M1?). Whitaker also ignores Neison's statement that his Leibnitz Kappa and Epsilon are lofty peaks in a range even farther over the limb than Leibnitz Alpha, Beta, Gamma and Delta. Instead, he identifies Leibnitz Kappa (which he "merges" with Leibnitz Beta, even though Neison's Leibnitz Beta is not described as the widest of his peaks), and Epsilon as relatively low peaks, at least as far onto the disk as the others. Be all that as it may, Whitaker's new "definitions" of what these feature names mean have been in use since 1954.
- Ewen Whitaker. 1954. The Lunar South Polar Regions. Journal of the British Astronomical Association, Vol. 64, No. 6, pp. 234-242.