King Crater is an exquisitely preserved impact crater on the lunar farside and an excellent candidate for future exploration by astronauts. The impact crater is ~77 km diameter, ~4 km deep, and has a spectacular claw-shaped central peak. A cascade of slumped blocks ring the crater walls, graphically illustrating the instability of transient crater walls in structures of this size. Flying over the crater reveals several ponds of debris that are thought to be impact melt and impact melt-bearing breccias that were produced when the collisional energy of an asteroid or comet melted a portion of the Moon's crust. Flow features and cooling cracks are visible in some of the deposits. Those ponds are excellent targets for future robotic spacecraft and/or astronauts wanting to determine the age of the impact event. Beyond the crater rim one sees additional ponds of material that were ejected from the crater while it was being excavated. Debris extends outward for a distance equivalent to about two crater diameters and, in some areas, seems to produced a rayed pattern. The distribution of ejected debris is not symmetrical about the crater, nor are the crater walls of uniform height, which are hints that suggest an impact trajectory from the south to the north.
The King Crater fly-by was generated in ESRI ArcGIS using ArcMAP and ArcSCENE environments. In ArcMAP, we started with a base image of King Crater (Apollo 16 Metric photograph AS16-1580) to reference all other imagery and data.
Then, high-resolution Apollo 16 Panoramic images (AS16-P-4997, AS16-P-4999, AS16-P-5001, AS16-P-5003, AS16-P-5005, AS16-P-5007, and AS16-P-5009) of the crater were cropped to reduce the amount of stretching associated with the image during referencing to our base image.
We then used Lunar Topographic Orthomaps (LTO-65c1, LTO-65d2, LTO-65c4, and LTO-65d3) of the King Crater area for digitizing contours and assigned elevation values to each contour according to the published topographic maps. These elevations were then used to develop a triangulated irregular network (TIN) which generates a three-dimensional representation of the digitized topographic map. Since all of these datasets have been referenced to an original base image, we were able to load these into ArcSCENE. High-resolution images were then draped over the three-dimensional TIN creating the representation of King Crater. Functions within ArcSCENE allow for the manipulation of the three-dimensional image and "flying" through them can be recorded and exported to a file for later viewing.
This flyover was produced by the LPI's 2008 Lunar Exploration Intern Program. This particular project was led by Kevin Thaisen and also involved Anna Losiak, Shoshana Weider, Katie O'Sullivan, and Tomas Kohout. David Kring advised the interns. Support for the program was provided by LPI and the NASA Lunar Science Institute (NLSI).