July 28, 2013
Giant Page of Little Features
compilation of LRO images by Howard Eskildsen, Florida
Concentric craters (CC) are bizarre little craters with an inner ring. Sometimes the inner ring looks like a donut, sometimes ballbearings, and other times more like a crater within a crater. Howard has now produced a new catalog of CC illustrated with images from the Lunar Reconnaissance Orbiter; he presented a paper on his results at the Astronomical League Conference in Atlanta that just ended a few minutes ago (at the time I write). Howard measured each of the craters' inner and outer diameters, their depth/diameter ratio, and their latitude and longitude, all from the LRO QuickMap. This is the type of investigation that amateurs can conduct that has lasting value. It provides a data set that accurately describes CC geometry, and that can be used to explore theories of CC origins. Similar useful projects could be done to catalog: the locations and heights of south polar peaks defining the South Pole - Aitken Basin, dimensions and locations of rilles and previously designated peaks, and the depths of all named craters. The existence of high quality spacecraft data does not eliminate the opportunity for amateurs to contribute to lunar understanding, it just transfers some of the work from outside at the eyepiece to inside at the computer.
Yesterday's LPOD: Twin Peaks
Tomorrow's LPOD: Three Troughs