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The use of materials for remote sensing of the Earth made it possible to identify a new type of crustal structures and features of their expression in relief. These are ring structures that complicate the structure of the studied structures of a linear type. As a result of the study of the morphology, geological and tectonic structure of ring structures, it was established that they represent formations of various origins: pluton-volcanic, cosmogenic, and anthropogenic. Cosmogenic structures of different ages and differ in various degrees of transformation. The relief of the identified cosmogenic structures within the limits of the Turan Plains, the Kazakh small hills and mountains of South-Eastern Kazakhstan is transformed by exogenous processes. The defining indicator features of cosmogenic structures include geomorphological, geological, structural tectonic, and also landscape. The degree of change in the initial cosmogenic relief depends on the time of formation, paleogeographic and modern physiographic conditions of the territories. Under the arid conditions of Kazakhstan’s epyhercynian platform, the main factor in the preservation of the “primary” morphology of meteorite craters is the lithologic stratigraphic complexes of the ring shaft. For the studied cosmogenic structures, in particular, the meteorite craters of Saryarka, a distinct geodynamic zoning of the development of exomorphogenesis processes is characteristic. The main exogenous processes include gravity-slope, surface washout, ravine and river erosion, processes of complex denudation and accumulation. The factors and processes of creating a modern crater relief morphology are established. These studies of cosmogenic ring structures of Kazakhstan have not only theoretical significance, revealing the role of cosmogenic processes of the formation of the Earth as a planet, but also have immediate practical importance. Meteorite craters are indicators of mineral deposits.

Impact craters are the most prominent topographic feature on the lunar surface, which will play a very important role in the construction of lunar bases and lunar surface activities in the future. Due to the large number of meteorite craters, different diameters and shapes, and the superposition of their morphologies, the artificial identification of meteorite craters is not only inaccurate but also inefficient. This paper first summarizes the significance of lunar impact crater research, then analyzes and summarizes the method of crater extraction, research status and the resulting data set, and finally summarizes the difficult problems and directions of future lunar impact crater identification research. Current crater-detection approaches fall into three categories, such as artificial detection, traditional automatic recognition and machine learning dtetection. With the development of computer, the convolutional neural network has become the trend of crater identification. Developing new images or data and training different network models is the key content of future research.

Robert Bedford (1874-1951), based in the isolated community of Kyancutta in South Australia, was a unique contributor to world geology, specifically in the field of meteorites and fossil archaeocyatha. Born Robert Arthur Buddicom in Shropshire, UK, he was an Oxford graduate who worked as a scientist in Freiberg, Naples, Birmingham and Shrewsbury as well as with the Natural History Museum, Kensington and the Plymouth Museum in the United Kingdom. He was a Fellow of the Geological Society of London, 1899-1910. In 1915, Buddicom changed his surname to Bedford and relocated to South Australia. During the 1920s, Bedford expanded his geological interests with the establishment of a public museum in Kyancutta in 1929. This included material previously collected and stored in the United Kingdom before being sent to Australia. Bedford was very successful in collecting material from the distant Henbury meteorite craters in Australia's Northern Territory, during three separate trips in 1931-1933. He became an authority on meteorites with much Henbury material being sent to the British Museum in London. However, Bedford's work on, and collecting of, meteorites resulted in a serious rift with the South Australian scientific establishment. Bedford is best known amongst geologists for his five taxonomic papers on the superbly preserved lower Cambrian archaeocyath fossils from the Ajax Mine near Beltana in South Australia's Flinders Ranges with field work commencing in about 1932 and extending until World War II. This research, describing thirty new genera and ninety-nine new species, was published in the Memoirs of the Kyancutta Museum, a journal that Bedford personally established and financed in 1934. These papers are regularly referenced today in international research dealing with archaeocyaths. Refereed/Peer-reviewed

This regional inventory and study of a globally uncommon landform type reveals similarities in form and process between craters produced by snow-avalanche and meteorite impacts. Fifty-two snow-avalanche impact craters (mean diameter 85 m, range 10–185 m) were investigated through field research, aerial photographic interpretation and analysis of topographic maps. The craters are sited on valley bottoms or lake margins at the foot of steep avalanche paths ( α = 28–59°), generally with an easterly aspect, where the slope of the final 200 m of the avalanche path ( β ) typically exceeds ~ 15°. Crater diameter correlates with the area of the avalanche start zone, which points to snow-avalanche volume as the main control on crater size. Proximal erosional scars (‘blast zones’) up to 40 m high indicate up-range ejection of material from the crater, assisted by air-launch of the avalanches and impulse waves generated by their impact into water-filled craters. Formation of distal mounds up to 12 m high of variable shape is favoured by more dispersed down-range deposition of ejecta. Key to the development of snow-avalanche impact craters is the repeated occurrence of topographically-focused snow avalanches that impact with a steep angle on unconsolidated sediment. Secondary craters or pits, a few metres in diameter, are attributed to the impact of individual boulders or smaller bodies of snow ejected from the main avalanche. The process of crater formation by low-density, low-velocity, large-volume snow flows occurring as multiple events is broadly comparable with cratering by single-event, high-density, high-velocity, small-volume projectiles such as small meteorites. Simple comparative modelling of snow-avalanche events associated with a crater of average size (diameter 85 m) indicates that the kinetic energy of a single snow-avalanche impact event is two orders of magnitude less than that of a single meteorite-impact event capable of producing a crater of similar size, which is consistent with the incremental development of snow-avalanche impact craters through the Holocene.

The Map of Astronomy in Europe has been designed to demonstrate how diverse information about a specific topic can be put together and presented in an attractive way in order to raise interest of society in the topic – in this case astronomical observations. The map represents information on several phenomena and objects related to astronomical observations in Europe and have been compiled from data collected from numerous publicly available sources during 2012–2013. The data were collected, transformed and processed using different methods to create geographic information on the visibility of solar eclipses and maximum possible percentage of sunshine hours for the geographic extent of Europe. Upon requests of amateur astronomers that made up the primary target group, the map was complemented by astronomical observatories, planetaria, astronomical clocks, meteorite craters and eventually by the most famous UNESCO World Heritage sites related to ancient or modern astronomical observations. Explanatory graphs, charts and lists of the objects were added for better understanding of the map information. Data verification, generalization and filtering, classification of the objects, building the GIS database, analysis of data, and cartographic visualization was performed at the Centre for Cartography at Vilnius University. Special attention was given to map design with an attempt to represent both very modern and historical objects in a consistent manner. The reference scale of the printed map is 1:8,000,000. It contains supplementary maps at scale 1:40,000,000 and 1:35,000,000. The size of the map image is 53 × 63 cm.

This letter presents a new method for crater detection based on infrequently used morphological characteristics. Pixels representing the center and rim of each crater are connected and used to deduce its location and size. Based on the different characteristics shown by simple bowl-shaped and complex craters, two strategies are developed. The centers and rims of simple craters are detected directly using the original digital elevation models (DEMs). When it comes to complex ones, the slopes of DEMs and their derivatives are extracted to replace the original models. Methods for removing false craters are also developed. The characteristics of the new crater detection algorithm are as follows: 1) It avoids some deficiencies of previous methods and thus can detect new craters to complete current crater catalogs; and 2) the efficiency of the method is guaranteed due to its low time complexity. The new algorithm performs better when compared with the flooded object-oriented approach using Chang'E-1 DEMs in the same sample region, and it extends the LU60645GT catalog by 26.8% and 37.5% in two distinct areas when the crater diameters are larger than 6 km.

Of the hundreds of distinct Aboriginal cultures of Australia, many have oral traditions rich in descriptions and explanations of comets, meteors, meteorites, airbursts, impact events, and impact craters. These views generally attribute these phenomena to spirits, death, and bad omens. There are also many traditions that describe the formation of meteorite craters as well as impact events that are not known to Western science.

Pollen analyses and radiocarbon dates from the bottom sediments in the Kaali main crater suggested that the crater group is at least 4000–5000 years old. Investigations of silicate impact micro-spherules in surrounding mires (Raukas et al. 1995) put the age about 7500–7600 yr BP. Recently we found both silicate and iron microspherules from organic sediments below well-dated beach ridge in Reo site what supports the conclusions that the most realistic age of the Kaali craters is 7600±50 14C BP (8335–8537 cal BP) and the meteorite fall was from SSE to NNW.

Luminescence Dating of the Morasko (Poland), Kaali, Ilumetsa and Tsõõrikmäe (Estonia) Meteorite Craters The TL dating of sinter crust of Morasko meteorites proves that the extraterrestrial matter fell about 5000 yr BP. Similar data were obtained for the Kaali impact. The OSL analyses show incomplete bleaching of old rock material especially in the Estonian craters. Almost all data obtained for the immediate impact area indicate ages younger than the Quaternary morphogenesis. The method used seems promising for determining the age of impacts and the origin of small depressions of unknown genesis.

In March 1932, Robert Bedford started a second expedition to Henbury. Robert and Bill Bedford, accompanied by Ben Peters, arrived at the crater site on 26 March. This time they stayed for ten days, “investigating and excavating the meteorite craters”.

We analyze the impact of large high velocity bodies on the surface of the Earth and obtain estimates of the size of the crater. We show that the atmosphere does not stop large bolides and their mass loss and heating during entry in the atmosphere can be neglected. Fil: Gratton, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; Argentina Fil: Perazzo, Carlos Alberto. Universidad Favaloro. Área de Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Multi-ring impact basins have been found on the surfaces of almost all planetary bodies in the Solar system with solid crusts. The details of their formation mechanism are still unclear. We present results of our numerical modeling of the formation of the largest known terrestrial impact craters. The geological and geophysical data on these structures accumulated over many decades are used to place constraints on the parameters of available numerical models with a dual purpose: (i) to choose parameters in available mechanical models for the crustal response of planetary bodies to a large impact and (ii) to use numerical modeling to refine the possible range of original diameters and the morphology of partially eroded terrestrial craters. We present numerical modeling results for the Vredefort, Sudbury, Chicxulub, and Popigai impact craters and compare these results with available geological and geophysical information.

The soil in and around the Kaali meteorite craters in the SE part of Saaremaa Island contains a large number of micrometeorites and abounds in pulverized extraterrestrial and impactite matter. The explosion with accompanying high temperatures resulted in the formation of glassy silicate spherules. These spherules were distributed over a large area, and allow to estimate the age of the impact at about 7500 years BP and correlate separated sequences. The extraterrestrial and explosive material in the Kaali area is diverse in form, colour and composition. The spherules may be of different origin, including industrial. From the methodological point of view, it is especially important to study spherules in the geologically established crater fields and their surroundings. The Kaali area provides an excellent polygon for this kind of studies.

Using orbital imaging radar, we detected a double circular structure, located in the southeastern part of the Libyan Desert, which is partially hidden under sandy sediments. Fieldwork confirmed it to be an unknown double impact crater, each crater having a diameter of about 10 km, younger than 140 Ma. Sampling on the site enabled the observation of quantities of shatter cone structures and impact breccias containing planar fractures. To cite this article: P. Paillou et al., C. R. Geoscience 335 (2003).

About 65 million years ago, a great change took place: more than half of the world's reptiles vanished along with more than half of all species of plants, and land and marine animals, including the dinosaurs. Mammals somehow survived and became the dominant large animal. One of these species lived long enough eventually to investigate the fossil record of its distant origins and ask the question: Who or what committed the mass murder?

— Precise radiometric age determination of the Kaalijarv meteorite craters on the island of Saaremaa in Estonia have so far proved inconclusive. Here we present trace element analyses of peat cores taken several kilometers away from the Kaalijarv craters that reveal a distinct Ir-enriched layer produced by the meteorite impact. By radiocarbon dating the peat cores, we have determined for the first time the precise age of the impact that generated the Kaalijarv craters. The calibrated date of the impact is 400–370 B.C. at ± 1σ.

It wouldn't cost much to find out if an asteroid or a comet is on a collision course with the Earth and then, if need be, mount a preemptive defense.

It has been found that in the resin of trees that have survived the Tunguska catastrophe, the quantity of microsized particles trapped at the moment of the event varies markedly from one site to another. The high density of particles found in the trees close to the epicentre may be an experimental point in favour of the fragmentation model recently developed for the Tunguska body.

Väitekirja elektrooniline versioon ei sisalda publikatsioone., Lõuna-Saksamaal paiknev ligikaudu 24-kilomeetrise läbimõõduga Reis’i meteoriidikraater (14,3–14,5 Ma) on üks paremini säilinud impaktstruktuure, olles heaks mudelstruktuuriks impakti järgsete protsesside uurimisel. Riesi kraater on ühtlasi ka üks esimesi impaktstruktuure, kus on kirjeldatud ja oletatud impakt-indutseeritud hüdrotermaalset mineralisatsiooni. Hüdrotermaalset muutust on seostatud ennekõike süeviitse kompleksiga ning on kirjeldatud detailsemalt Newsom et al. (1986), Osinski (2003,2004) ja Osinski et al (2004) töödes. Kraatrit täitvate süeviitide hüdrotermaalseid muutuseid/ilminguid iseloomustab sekundaarne savimineralisatsioon ja teoliidistumine, millega kaasneb varajane K-metasomatism koos albitiseerumise ning kloritiseerumise ilmingutega temperatuuridel ~200–300°C (Osinski 2005). Samas pole pindmiste süeviitide hüdrotermaalne mineralisatsioon nii selgelt märgatav/eristatav ning seda on seostatud impaktklaasi muutumisel tekkima hakanud montmorilloniidi tüüpi savifaasiga (Newsom et al 1986), mille alusel on hinnatud pindmiste süeviitide muutumistemperatuuriks < 130 °C. Antud uurimuse mineraloogilised, geokeemilised ja stabiilsete isotoopide analüüsid näitavad, et hüdrotermaalsete protsesside mõju Riesi meteoriidikraatri pindmiste süeviitide muutumisele praktiliselt puudub või ei ole eristatav ning valdav süeviitide muutumine toimub pindmisel murenemisel, madala pH (5–7) ja ioonkontsentratsiooniga (nt sademete vesi) veelises keskkonnas. Erinevalt pindmistest süeviitidest iseloomustavad kraatrit täitvate süeviitide hüdrotermaalseid muutuseid/ilminguid sekundaarne savimineralisatsioon ja tseoliidistumine ning satabiilsete isotoopide uuringud näitavad, et võrreldes pindmiste süeviitidega on nende muutumine toimunud kõrgematemperatuurilises (~100 °C) fluidis, mille pH varieerus >7–8 ning mis võis olla kõrgenenud ioonkontsentratsiooniga. Selline fluidikoostis tõendab sisemiste süeviitide muutumisel tekkinud savimineraalide hüdrotermaalset päritolu anioonhüdrolüütiliselt neutraliseeritud ja lahustuvate komponentide suhtes rikastunud fluidist., The 24-km diameter Ries crater, in Germany, is one of the best-preserved terrestrial complex impact structures; providing a good opportunity to study the evolution of the post-impact cooling in impact craters. The mineralogical, geochemical and stable isotope studies of the surficial and crater- fill suevites from the Ries crater has provided additional constraints on the mineralogical alteration of the Ries impactites and on the origin and evolution of the (geothermal) fluids that were involved in the formation of alteration mineralogy. Previous studies (Newsom et al., 1986; Osinski, 2005) have proposed that the Ries crater suevites have been altered by post-impact aqueous and hydrothermal fluids. Based on mineralogical grounds Newsom et al. (1986) suggested that the surficial suevite was altered at temperatures < 130 °C, and Osinski suggested that the crater-fill suevite was altered at temperatures from 200 – 300 °C. Our mineralogical, geochemical and stable isotope studies suggests that the alteration in surficial suevites is driven mainly by ambient low-temperature weathering, rather than hydrothermal processes and the alteration occured at lower pH and in slightly acidic environment (percolation of meteoric water), showing that the smectite in surficial suevites precipitated in equilibrium with meteoritic fluids. However, alteration in crater filling sequence occurred in the presence of meteoric water-dominated fluid circulation at higher temperatures (40 to 110 °C) than the surficial suevites, but possibly within a normal thermal gradient. The modeled δ11B composition of crater-fill suevites, on the other hand, indicate that the alteration in the crater-fill suevites took place at elevated pH (>8–9). The elevated pH of the alteration fluids in crater filling suevites is possibly related to the effective removal of the available H+ ions in hydrothermal fluid (evolved meteoric water) through anion hydrolysis of impact glass and primary silicates.

A Corvid meteor shower was observed once, in late June of 1937. On June 18, 1178, the upper horn of a crescent Moon was reported to have split, with fire and sparks emanating from the division point. This report was interpreted to be a description of events related to the formation of the lunar crater, Giordano Bruno. Corvid meteoroids are judged to be Giordano Bruno ejecta fragments based on similarities in their heliocentric positions, directions of motion, and speeds. Commensurability relationships between meteoroid/ejecta and Earth-Moon system orbital periods enable definitive predictions of Corvid showers in the years 2003 and/or 2006.

The largest known Cenozoic impact craters with the most accurately measured ages are found to correlate very closely with geologic stage boundaries. The level of confidence in this result is 98-99 percent even under the most pessimistic assumptions concerning dating errors. One or more large impacts may have led, in at least some cases, to the extinctions and first appearances of biotic species that mark many of the geologic stage boundaries.

Results are presented from the analyses of small ballistically dispersed melt samples (occurring in the form of aerodynamically shaped spheres, dumbbells, and teardrops) from the Wabar Crater (Saudi Arabia) and of melts from the Wabar and Nejed meteorites. On the basis of the data obtained and of models for crater forming processes it is concluded that the ballistically-dispersed glasses were formed from material at shallow levels in the target zone where temperatures were higher and where intimate physical contact with the disrupting impactor was achieved. Siderophile element fractionation was completed early, while the impactor was undergoing decompression and prior to mixing with the target glasses.

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.

The source crater of the youngest and largest of the tektite strewnfields, the Australasian strewnfield, has not been located. A number of lines of evidence indicate that the Muong Nong-type tektites, primarily found in Indochina, are more primitive than the much more abundant and widespread splash-form tektites, and are proximal to the source. In this study the spatial distribution of Muong Nong-type tektite sites and chemical character have been used to indicate the approximate location of the source. The variation of Muong Nong-type tektite chemical composition appears to be caused by mixing of two silicate rock end-members and a small amount of limestone, and not by vapor fractionation. The variation in composition is not random, and does not support in situ melting or multiple impact theories. The distribution of both Muong Nong and splash-form tektite sites suggest the source is in a limited area near the southern part of the Thailand-Laos border.

A quantitative model in which the parabolic features are produced by the interaction of the zonal winds with material ejected ballistically from the impact crater is proposed. As the ejecta particles fall through the atmosphere, the winds transport them downwind from their entry point, smaller particles being transported a greater distance. Since the ejecta distribution is initially axially symmetric and smaller particles are thrown farther from the crater, the winds blow the particles on the upwind side back upon one another, leading to a pile-up of material. On the downwind side, the winds disperse the ejecta particles and no pile-up occurs. The resulting thickness distribution on the Venusian surface matches the observed parabolic features closely. The dual parabolic features associated with the crater Carson is also explained by this model.

A new method of dating the surface exposure of rocks from in situ production of 10Be and 26Al has been applied to determine the age of Meteor Crater, Arizona. A lower bound on the crater age of 49,200 ± 1,700 years has been obtained by this method.

A study of the cause of the coloration of blue zhamanshinites, which are glassy impact melt rocks from the Zhamanshin crater in the USSR are reported. It is found that the blue color results from Rayleigh scattering from spherical, 100 nm-diameter inclusions of a separate Ca-Fe-Mg-P-rich silicate glass. These observations can best be explained by the operation of liquid immiscibility in the zhamanshinite melt, and suggest that liquid immiscibility may have a more general role in impactite evolution.

The technique of photoclinometry has frequently been used to determine planetary topography without proper consideration of possible sources of error. Previous studies of error sources have been limited in extent and have overlooked the importance of factors such as atmospheric scattering and the choice of a surface photometric function. This paper adopts a thorough and more direct approach to error analysis, whereby known topography is compared with photoclinometric profiles derived from synthetic quantised reflectance scans.

The assumptions used to determine whether active comets or earth-crossing asteroids currently dominate the terrestrial cratering rate are reviewed and intercompared. The principal sources of uncertainty are the number and mass distributions of earth-crossing bodies, the adopted crater-diameter scaling law, and the question whether the present populations are in a steady state. Models in which long-period comets make a significant contribution to the cratering rate imply an excessive cometary mass (≳ 100 M ⊕ ) for the dynamically active Oort cloud. For this and other reasons it is concluded that the majority of observed terrestrial or lunar craters larger than about 10 km are probably produced by earth-crossing asteroids. This emphasizes the importance of studies aimed at determining whether earth-crossing asteroids are themselves predominantly cometary in origin or asteroidal.

Analysis of craters found on polished plates exposed during Skylab has provided data for a flux measurement over the mass range 10−15 to 10−7 gms. Chemical analysis of residues in the craters shows a high incidence of aluminium. A variety of morphological forms are described.

The compositional range within the Canyon Diablo (CD) iron meteorites associated with the formation of the Meteor Crater (Arizona) was examined, using the INAA to analyze a set of CD samples consisting of nine irons collected within 7 km of the Meteor Crater, four Arizona IAB irons that were identified by Wasson (1968) as transported CD fragments, and irons from Las Vegas (Nevada) and Moab (Utah) that Buchwald (1975) suggested to be transported CD fragments. Results show that the irons named Helt Township, Idaho, Las Vegas, Mamaroneck, Moab, and Pulaski County are, most likely, mislabeled CD specimens. On the other hand, meteorites named Alexander County, Allan Hills A77283, Ashfork, Fairfield, and Rifle are identified as compositionally distinct independent falls.

— Fifty-odd years of tektite research are reviewed, proceeding from the discovery of the first North American tektites in 1936. This included the early recognition that tektites were terrestrial objects rather than meteorites and that the glassy particles in tektites were fused quartz (lechatelierite). Later, during National Science Foundation-supported research, it was found that some tektites appeared to have formed as puddles of melt, that the content and character of bubbles in lechatelierite can be used as a relative temperature scale, that rayed bubbles in tektites formed from hydrous minerals, that bubbles in tektites formed chiefly from water which was absorbed into the walls of the bubbles leaving vacuums, and that “fingers” in the surficial part of some tektites may have formed by differential volatilization. Some unpublished observations and adventures are briefly reported.

The presence of central peak craters and the absence of central pit craters on Triton implies a surface rigidity similar to the Saturnian and Uranian satellites and stronger than that of the Jupiter satellites Ganymede and Callisto. Tectonically degraded terrain may exist at the antipode of the large impact structure on 1989N1. Dome craters on Triton may represent a form of solid state volcanism.

Knowledge of the near-earth asteroids (Apollo, Amor, and Aten groups) has increased enormously over the last 10 to 15 years. This has been due in large part to the success of programs that have systematically searched for these objects. These programs have been motivated by the apparent relationships of the near-earth asteroids to terrestrial impact cratering, meteorites, and comets, and their relative accessibility for asteroid missions. Discovery of new near-earth asteroids is fundamental to all other studies, from theoretical modeling of their populations to the determination of their physical characteristics by various remote-sensing techniques. The methods that have been used to find these objects are reviewed, and ways in which the search for near-earth asteroids can be expanded are discussed.

The review of the data of the analysis of images of Venera 15/16 mission is done. These data are used to make some predictions of how many impact craters the MAGELLAN space probe would see on Venus and how they would look. The possible trends of crater areal distribution and characteristic features of the size-frequency relationship are discussed.

Static discharge patterns, seen in a thin layer of dust on a CRT, have a striking resemblance to many features seen on moons and asteroids. What might this low tech experiment reveal about how some planetary surface features are formed'.' Many features on moons and asteroids are hard to explain through the mechanism of an impact. The anomalies are numerous but the most obvious challenge comes from chained craters which appear to overlap each other or lay in very close linear proximity.

Using L-band SAR data from JERS-1 and ALOS, we produce regional mosaics of Sahara in order to map subsurface geology. A first mosaic of eastern Sahara using more than 1600 JERS-1 scenes allowed the discovery of unknown paleo-rivers, faults, and impact craters. On-going work concerns a new L- band high-quality mosaic of the entire Sahara, based on ALOS/PALSAR data.

Kaali meteorite craters are located on the Island of Saaremaa, 18 km northeast of its chief town Kuressaare, being the first established meteorite craters in Europe. Nine meteorite craters formed about 7500 years BP as a result of single iron meteorite falling apart, which was a typical coarse octahedrite with Fe/Ni ratio being equal to 91.5/8.3. Craters are spread within a wildlife reserve of the total area about 50 ha. Craters were formed in a two-layered target rock: till and dolomite. The diameter of the main crater is 105–110 m.

In the summer of 1998, several members of Carnegie Mellon University's (CMUs) Autonomous Helicopter Project team joined NASA on a multidisciplinary expedition to the Canadian Arctic's Haughton Crater. NASA was willing to travel to such a remote corner of the globe because of its similarity to an even more remote locale-Mars. Researchers are studying the 23-million-year-old meteorite impact crater in the hope of learning more about Mars's environment. While there, they also tested a number of technologies that will enable future exploration of Mars, including CMU's autonomous helicopter.

Interplanetary space is populated with large numbers of small bodies known as meteorites, which are in orbits that can intersect those of planets and moons. Therefore, individual impacts appear on the surfaces of planetary bodies which are called impact craters. While impacting meteorites are useful to determine the early solar system processes, resultant impact craters are useful to determine the ages of the surfaces and related erosional effects on the body. At Canakkale Onsekiz Mart University (COMU) we aim to create a Meteorite Impact Craters Data Base for Turkey in a computer environment. The data base will be reachable through internet for wider use. Preparations and actions for this exercise are described. For the initial phase, we have collected related information through literature including papers and thesis on the topic. We classify our present efforts for acquisition of information along the following lines on: 1) Meteorites which have fallen down to Turkey recently, i.e. Antalya meteorite in 2001, Afyon meteorite in 2002 and others; 2) Meteorites and impact craters, mentioned in historical records, i.e., Gallipoli meteorite (467 BC); Birgi meteorite (1335 AD) etc.; 3) Candidate impact craters in Turkey which were studied earlier; 4) Other events that can be recognized through satellite images and maps; 5) New events during our preparations. Present candidates and established structures will be investigated and relevant data will be used for the aimed data base.

Wind-abraded rocks, ripples, drifts, and other deposits of windblown sediments are seen at the Columbia Memorial Station where the Spirit rover landed. Orientations of these features suggest formative winds from the north-northwest, consistent with predictions from atmospheric models of afternoon winds in Gusev Crater. Cuttings from the rover Rock Abrasion Tool are asymmetrically distributed toward the south-southeast, suggesting active winds from the north-northwest at the time (midday) of the abrasion operations. Characteristics of some rocks, such as a two-toned appearance, suggest that they were possibly buried and exhumed on the order of 5 to 60 centimeters by wind deflation, depending on location.

[1] Luminescence dating has been used to find the age of meteorite impact craters at Wabar (Al Hadida) in Saudi Arabia. The luminescence characteristics of the shocked material were determined. Using a variety of luminescence dating techniques applied to impactite formed by the meteorite, and to the underlying sand, the age is found to be 290 ± 38 years. A comparison is made with two possible historically recorded ages. An impact as young as this has implications for the assessment of hazards from the impact on Earth of small meteorites.

Glassy objects reportedly found in Pima County, Arizona, have been identified as tektites. A field survey of the area where they were said to occur, however, did not produce any other tektites, nor did it reveal any other geologic features that might indicate a nearby impact crater. The major-, minor-, and trace-element composition of one specimen is similar to those measured in indochinites, which suggests the objects reportedly from Pima County were instead transported to southern Arizona from Indochina by people.

Research at the University of California, Berkeley, was supported by NASA through subcontract LRI-99-101 from the Lunar Research Institute.