GIBEON INTRODUCTION

Recovered from the edge of the Kalahari Desert, Gibeon iron meteorites are the bounty of a huge meteorite shower that occurred thousands of years ago when an enormous iron mass (or masses) slammed into Earth’s upper atmosphere before exploding and raining down upon what is now Namibia. Local tribesmen located these specimens the aid of a metal detector, a method not quite in the tradition of their predecessors who recovered surface specimens to fashion into spear points and other tools. It was not until 1836 that a British explorer first reported that tribesmen were making such use of meteoric iron, and so the newly-named Gibeon was described as having been “found” in that year. Due to a relatively high nickel content (8%), Gibeon is ductile and not as prone to oxidizing as other iron meteorites. When cut and etched, Gibeon exhibits a brilliant fine-octahedral pattern (see lot 24) that reveals the crystalline structure of its two alloys, kamacite and taenite—an exquisite natural design known as a Widmanstätten pattern. The following three specimens include two complete and one etched examples.

DELIVERY MECHANISM OF METEORITES FROM THE MOON AND MARS

When asteroids strike the surface of the Moon and Mars, portions of these planetary bodies are launched into space in much the same way as when a child dives onto a bed and dust is launched into the air. In addition, sites have been identified on Mars where a tremendous asteroid appears to have tangentially struck the Martian surface and “kicked” portions of Mars into space. There are no known meteorites from Venus and the likelihood is remote given the high escape velocity necessary for such objects to overcome the thick Venusian atmosphere and strong gravitational field. To date the Meteoritical Bulletin has published findings on 56 lunar meteorites. The overwhelming majority of the tens of thousands of craters seen on the lunar surface were created by asteroid impacts; such craters remain preserved as the Moon has no weather or any active geological process that would change the character of the lunar surface—which is not the situation on Earth and thus our largely crater-free surface.