The Strolling Astronomer Feature Story: Concentric Lunar Craters By Howard Eskildsen,
[email protected] Online Readers Left-click your mouse on the e-mail address in blue text to contact the author of this article, and selected references also in blue text at the end of this paper for more information there. This paper by ALPO member and astrophotographer Howard Eskidsen is only one of many that ratios were calculated using Lunar averaged 0.065, much shallower than were presented at ALCon 2013, Reconnaissance Orbiter data. Crater the T/D ratio of 0.20 that is typical for held in Atlanta, Georgia. coordinates were reproducible to within non-concentric craters. Mean crater rim 0.02°. Outer rim diameters (D) ranged elevations were below the mean lunar Abstract from 2.3km to 24.2 km with the mean radius of 1737.4 km with the mean 1.5 8.2 km with error of ± 0.2 km. Inner km lower than the mean lunar radius. Fifty-five concentric caters were toroid rim diameters (T) averaged 4.3 identified and measured for diameter, km, and calculated toroid to diameter depth, toroid crest diameter, ratios (T/D ratio) averaged 0.51. The d/ coordinates, and depth/diameter (d/D) D ratios for the concentric craters Table 1: Eastern Hemisphere Diameter Data Page 36 Volume 56, No. 1, Winter 2014 The Strolling Astronomer Table 1A: Eastern Hemisphere Elevation/Depth Data Concentric Craters pure highland areas. None are found in While the most notable concentrics have A small percentage of craters that would the central maria (Wood 1978).