Lunar Research
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Lunar Research |
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In the course of processing the Lunar Orbiter photographs, I investigated the nature of the artifacts of scanning and reproduction of the images and the methods of cleaning the photos. The results of these studies were published as abstracts at the annual Lunar and Planetary Science Conventions (LPSC) and are available on this web site. As a result of hearing other contributions to the LPSC and other meetings, and writing notes on the geology of the photos for my book, I became interested in the nature of large impacts on the Moon. Specifically, my interests have focussed on the multi-ringed basins, those impacts that are typically 300 km or more in diameter. There are two major puzzles about these basins that I am investigating:
My early work concentrated on the distribution of basins by size and position (see the abstract entitled "Size Distribution of Multi-ringed Basins" on this web site). This abstract, and additional work that I presented in the poster session in March 2005, show that nearly all basins whose diameter exceeds 500 km are concentrated in a circular zone of 75 degrees radius whose center is at about 29 degrees east longitude and 2 degrees south latitude. Recently, I have found the early basin underlying the region of large maria (see "The Near Side Megabasin") . This basin, centered at 8.5 N and 22 E, is over 100 degrees in radius and covers half of the Moon, including nearly all of the near side. It coincides with lower elevations and thinner crust: its ejecta accounts for the deeper crust on the far side. In preparation for the search for the new large basin, I have examined the Orientale, Moscoviense, Korolev, Humboltianum, Grimaldi, Hertzsprung, Humorum, and Apollo Basins and have established a common model for the internal basin and its external ejecta (see "Radial profiles of lunar basins). This model has been successfully extended for the very large South Pole -Aitken and even larger Near Side Megabasin. In 2007, Hikida and Wieczorek published a new model of the crustal thickness. This led to my awareness that topography and crustal thickness are consistent with the Near Side Megabasin event if it was ssubject to full isostatic compensation. This point is made in my book "The Far Side of the Moon: a Photographic Guide" (Springer, 2008) and in the paper "A Large Basin on the Near Side of the Moon", Earth Moon and Science, 2008.
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Major Publications Stragraphy of Lunar Craters by Don E. Wilhelms and Charles J. Byrne, January 23, 2009. This document is presented here for the first time. It is based on the Geographic History of the Moon (GHM, Don. E. Williams, 1987). It lists explicitly the estimated strata of over 1500 large lunar craters, along with their latitude, longitude, strata (pre-Nectarian, Nectarian, Lower Imbrian, Upper Imbrian, Eratosthenian, and Copernican) and provides comments by Dr. Wilhelms. The body of this document is in the form of a series of tables corresponding to Plates 6 through 12 of the GHM and may be considered a key to those plates. In addition to the body there is Appendix A, Lunar Craters Sorted by Name and Appendix B, Lunar Craters Sorted by LAC Chart. A Large Basin on
the Near Side of the Moon The link above is to the manuscript version (.pdf, 2 Megabytes). The published paper is at http://dx.doi.org/10.1007/s11038-007-9225-8. Other Publications (most documents are .pdf files) The Near Side Megabasin
of the Moon Radial Profiles of Lunar
Basins Size
Distributions of Lunar Basins Gravity
Focussing of Swarms of Potential
Impactors Evidence
for Three Basins beneath Oceanus
Procellarum
Proposed
High-Level Regional Focal Points for Lunar
Geography Corrections
of Image Motion Smear in Photo from Lunar Orbiter
Mission I
A
New Moon: Improved Lunar Orbiter Mosaics Automated
Cosmetic Improvement of Mosaics from the Lunar
Orbiter Atlas
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