Historical Notes on the Odessa Meteorite Crater

Abstract. This is a history of the identification of the crater by the late Daniel Moreau Barringer, Jr., in 1926, and subsequent exploration. The findings at Odessa and at Barringer Crater are compared and problems posed.     

Heating of Ejecta from a Meteorite Crater by the Perturbed Atmosphere

Numerical simulation methods are used to investigate the thermal evolution of ejecta from a meteorite crater in the interaction with the perturbed atmosphere in the first few minutes after the impact. The study considers the role of air radiation, collisions of air molecules with the body’s surface, and the heat transfer into the interior in the heat exchange of the ejecta and reveals the possibility of additional heating (compared with that at the time of the impact), which affects the geochemical and paleomagnetic properties of the ejecta.     

Surviving Metal in Meteoritic Iron Oxide from The Wolf Creek,Western Australia,Meteorite Crater

Abstract. Some very small particles of metal, revealed by polishing a chunk of Wolf Creek meteoritic iron oxide, appear to consist entirely of moderately shocked kamacite. The apparent lack of surviving taenite tentatively suggests that the Wolf Creek crater was formed by a hexahedrite, although medium octahedrites have recently been found within 4000 meters of the crater. Macrosegregation of nickel within the Wolf Creek meteoroid could account for the discrepancy. Further research on surviving metal is indicated.     

The Oshkosh Meteorite

Abstract In the fall of 1961, fragments of an olivine-bronzite chondrite were found about 2 miles NNW of Oshkosh, Wisconsin, the total weight being 144.8 g. This paper fixes the exact location and describes the circumstances of the find.     

Meteorite transport—Revisited

Meteorites are delivered from the asteroid belt by way of chaotic zones (Wisdom 1985a). The dominant sources are believed to be the chaotic zones associated with the ν₆ secular resonance, the 3:1 mean motion resonance, and the 5:2 mean motion resonance. Though the meteorite transport process has been previously studied, those studies have limitations. Here I reassess the meteorite transport process with fewer limitations. Prior studies have not been able to reproduce the afternoon excess (the fact that approximately twice as many meteorites fall in the afternoon as in the morning) and suggested that the afternoon excess is an observational artifact; here it is shown that the afternoon excess is in fact consistent with the transport of meteorites by way of chaotic zones in the asteroid belt. By studying models with and without the inner planets it is found that the inner planets significantly speed up the transport of meteorites.     

Meteorite fusion crust variability

Abstract— Two assumptions commonly employed in meteorite interpretation are that fusion crust compositions represent the bulk‐rock chemistry of the interior meteorite and that the vesicles within the fusion crust result from the release of implanted solar wind volatiles. Electron microprobe analyses of thin sections from lunar meteorite Miller Range (MIL) 05035 and eucrite Bates Nunataks (BTN) 00300 were performed to determine if the chemical compositions of the fusion crust varied and/or represented the published bulk rock composition. It was determined that fusion crust compositions are significantly influenced by the incorporation of fragments from the substrate, and by the composition and grain size of those minerals. Because of compositional heterogeneities throughout the meteorite, one cannot assume that fusion crust composition represents the bulk rock composition. If the compositional variability within the fusion crust and mineralogical differences among thin sections goes unnoticed, then the perceived composition and petrogenetic models of formation will be incorrect. The formation of vesicles within these fusion crusts were also compared to current theories attributing vesicles to a solar wind origin. Previous work from the STONE‐5 experiment, where terrestrial rocks were exposed on the exterior of a spacecraft heatshield, produced a vesicular fusion crust without prolonged exposure to solar wind suggesting that the high temperatures experienced by a meteorite during passage through the Earth's atmosphere are sufficient to cause boiling of the melt. Therefore, the assumption that all vesicles found within a fusion crust are due to the release of implanted volatiles of solar wind may not be justified.     

Finding a New Meteorite

Following is an account of the incidents relevant to the discovery of several new meteorites, in particular a small stony specimen (an aerolite) weighing about 4 pounds, found recently on a farm in the northern part of Cowley County, Kansas.     

The Belle Plaine III Meteorite

Abstract The Belle Plaine III meteorite is one of three meteorites, all of about the same size, found within a 2 mile strip southeast of Belle Plaine, Kansas. The meteorite weighs 23.9 kg, and consists of about 28% metallic minerals and 72% silicates. Nickel-iron, magnetite, hypersthene and olivene are the major constituents. The meteorite is an olivene-hypersthene chondrite.     

An Iron Meteorite from Akyumak

Abstract— The microstructure of an iron meteorite which fell near Akyumak, East Anatolia, Turkey on 2 August 1981 has been examined and its composition determined. The Ni content is 7.7% and kamacite bandwidth is 0.32 ± 0.06 mm. The kamacite contains Neumann bands and some daubreelite inclusions. Taenite and plessite account for about 45 to 50% of the metal; finger, cellular and net plessite are observed. Gallium (1.9 ppm), Ge (< 40 ppm) and Ir (1.81 ppm) were determined by neutron activation. The microstructural observations and chemical data show Akyumak to be a fine octahedrite and a member of group IVA.     

Meteorite finds from southern Tunisia

Abstract— We report on the meteorite search campaign of April 2008, conducted by a joint Tunisian‐Italian scientific expedition in southern Tunisia (Dahar region). Nine likely unpaired meteorites (seven H‐class and two L‐class chondrites) totalling ?1.3 kg were recovered by exploring an approximately 45 km²area, therefore demonstrating that southern Tunisia is a suitable terrain for systematic searches for meteorites.     

Destination: Earth. Martian Meteorite Delivery

The delivery dynamics of martian meteorites are examined by means of a direct numerical simulation of their orbital evolution. The dynamics in the martian region are dominated by secular resonant effects, not by close encounters with Mars. These secular effects rapidly (∼1 Myr) transport martian ejecta to Earth-crossing orbits. The measured cosmic-ray exposure ages of the martian meteorites are consistent with their being directly launched as small bodies from the martian surface by impacts over the last ?15 Myr. Collisional effects and being driven into the Sun efficiently destroy martian meteoroids in space on time scales of order 10 Myr. The implications of these results for the launch mechanism and microorganism transport are discussed.     

High Inclination Meteorite Streams can Exist

Meteorites represent bodies at the larger end of the meteoroid size spectrum since they are large enough to survive ablation in the Earth’s atmosphere. They are thus far less numerous than normal meteoroids that become meteors. A number of meteorites can arrive at around the same time and location and so in some sense represent a stream, but these are just recent fragmentations. Most meteors, according to their cosmic ray exposure age are at least 10 million years old. This is roughly also the timescale for the onset of chaos in the inner Solar System and so conventional wisdom is that meteorites can not survive on such orbits for such a time span and that they certainly cannot survive as coherent streams. We investigate numerically the survival of streams for this time interval.     

Meteorite transport—Revisited II

In Wisdom (2017), I presented new simulations of meteorite transport from the chaotic zones associated with major resonances in the asteroid belt: the ν₆ secular resonance, the 3:1 mean motion resonance with Jupiter, and the 5:2 mean motion resonance with Jupiter. I found that the observed afternoon excess (the fact that approximately twice as many meteorites fall in the afternoon as in the morning) of the ordinary chondrites is consistent with chaotic transport from the 3:1 resonance, contradicting prior reports. Here I report an additional study of the transport of meteorites from ν₆ secular resonance and the 3:1 mean motion resonance. I use an improved integration algorithm, and study the evolution of more particles. I confirm that the afternoon excess of the ordinary chondrites is consistent with transport from the 3:1 resonance.     

Meteorite and meteoroid: New comprehensive definitions

Abstract– Meteorites have traditionally been defined as solid objects that have fallen to Earth from space. This definition, however, is no longer adequate. In recent decades, man‐made objects have fallen to Earth from space, meteorites have been identified on the Moon and Mars, and small interplanetary objects have impacted orbiting spacecraft. Taking these facts and other potential complications into consideration, we offer new comprehensive definitions of the terms “meteorite,”“meteoroid,” and their smaller counterparts: A meteoroid is a 10‐μm to 1‐m‐size natural solid object moving in interplanetary space. A micrometeoroid is a meteoroid 10 μm to 2 mm in size. A meteorite is a natural, solid object larger than 10 μm in size, derived from a celestial body, that was transported by natural means from the body on which it formed to a region outside the dominant gravitational influence of that body and that later collided with a natural or artificial body larger than itself (even if it is the same body from which it was launched). Weathering and other secondary processes do not affect an object’s status as a meteorite as long as something recognizable remains of its original minerals or structure. An object loses its status as a meteorite if it is incorporated into a larger rock that becomes a meteorite itself. A micrometeorite is a meteorite between 10 μm and 2 mm in size. Meteorite– “a solid substance or body falling from the high regions of the atmosphere” ( Craig 1849 ); “[a] mass of stone and iron that ha[s] been directly observed to have fallen down to the Earth’s surface” (translated from Cohen 1894 ); “[a] solid bod[y] which came to the earth from space” ( Farrington 1915 ); “A mass of solid matter, too small to be considered an asteroid; either traveling through space as an unattached unit, or having landed on the earth and still retaining its identity” ( Nininger 1933 ); “[a meteoroid] which has reached the surface of the Earth without being vaporized” (1958 International Astronomical Union (IAU) definition, quoted by Millman 1961 ); “a solid body which has arrived on the Earth from outer space” ( Mason 1962 ); “[a] solid bod[y] which reach[es] the Earth (or the Moon, Mars, etc.) from interplanetary space and [is] large enough to survive passage through the Earth’s (or Mars’, etc.) atmosphere” ( Gomes and Keil 1980 ); “[a meteoroid] that survive[s] passage through the atmosphere and fall[s] to earth” ( Burke 1986 ); “a recovered fragment of a meteoroid that has survived transit through the earth’s atmosphere” ( McSween 1987 ); “[a] solid bod[y] of extraterrestrial material that penetrate[s] the atmosphere and reach[es] the Earth’s surface” ( Krot et al. 2003 ).     

Heating of the Lithosphere during Meteorite Cratering

The formation of thermal anomalies around the impact sites of large cosmic bodies on the Earth is studied. The parameters of thermal anomalies are compared for the impacts of bodies of various scales—from one to several hundred kilometers in diameter. The cooling time of the rocks under impact craters of various scales is estimated. The estimates obtained are used to model the input of heat by the impacts of small (less than 500 km in diameter) planetesimals late in the accretion of the Earth. The boundary conditions for calculating the thermal evolution of the early Earth are refined by simultaneously analyzing the sizes of impact thermal anomalies and the model size distributions of projectiles (the mass spectrum of planetesimals).     

Meteorite stranding surfaces and the Greenland icesheet

Abstract— Thirty years of recoveries in East Antarctica have led to significant understanding of the regional characteristics associated with meteorite stranding surfaces. In Antarctica these sites are characterized by patches of snow‐free blue ice at high altitude on the icesheet in regions where iceflow is highly restricted. Melting is extremely rare or absent and sublimation rates are high, even though meteorite stranding surfaces are predominantly found within regions where accumulation typically dominates. Localized environmental conditions that persist for thousands of years or longer appear to be the dominant factor rather than shorter‐term or seasonal cycles. In this paper we describe our discovery of regions in Northeast Greenland with blue ice areas that exhibit many of the requisite characteristics, suggesting that they are excellent prospects for future meteorite recovery efforts.     

A probable new Meteor Impact Crater

Kedarath Fountain-Pond, Gujarat, India is a probable new Meteor Impact Crater Fountain-Pond which is irregular, very old and eroded. In this note we report some preliminary observations about it and invite attention of international community of scientists towards its existence and studies and to establish finally whether or not, it is a Meteor Impact Crater. We have also taken some steps in this direction.     

On the Origin of the Last Meteorite Parent Bodies

The existence of gaps in the perihelion distribution of the orbits of multikilometer-sized asteroids that approach the orbits of terrestrial-group planets is confirmed. This property of the orbits of large asteroids suggests the existence among them of a family of last meteorite parent bodies. Astrophysical data were considered for S-asteroids of the Main Belt and those that approach terrestrial planets. The u–x color index, which is related to the position of the absorption band at 950 nm in the asteroid spectra, was chosen for a qualitative comparison of the surface composition of these asteroids (identical or differing composition). The u – x color-index distributions were analyzed statistically according to the perihelion (q) and mean heliocentric distances (a) of the S-asteroids. It is shown that these distributions are -shaped, peaking at q 1.8 AU and a 2.2 AU. The wings of the distributions can be approximated by linear regressions. A comparison of the u – x color-index mean values for S-asteroids in the regions of the Earth and Mars and of the Main Belt prompts the conclusion that the last meteorite parent bodies in the vicinity of the orbits of the Earth and Mars come primarily from various regions of the asteroid Main Belt.     

The Anoka,Minnesota, Iron Meteorite*

Abstract The Anoka, Minnesota, meteorite was found on the Joe Fields Farm at location coordinates 45° 12′ N, 93° 26′ W. It is a fine octahedrite distinguished by large fields of dense plessite. The chemical analysis of the meteorite is 84.9 percent iron, 11.75 nickel and 0.51 cobalt.