Petrographic survey of lunar regolith breccias

Regolith breccias from the Moon and from parent bodies of some meteorites may provide samples of ancient regoliths which have been frozen in time. If these rocks were essentially closed at some earlier time and that time can be determined, then these rocks provide a record of conditions in the solar system at that point in time. A survey of regolith breccias in the Apollo collection was conducted concentrating initially on Apollo 15 and 16. All available thin sections for 32 regolith breccias from Apollo 15 and 19 breccias from Apollo 16 were surveyed. These are most of the returned regolith breccias larger than 1 cm from these two mission. For comparison several fragmental matrix breccias which do not strictly qualify as regolith breccias were investigated. The criteria for classification as a regolith breccia is the presence of identifiable soil components such as glass spheres or agglutinates. The breccias are classified according to their intergranular porosity. In addition the fracture porosity is noted, and the relative abundance of agglutinates and spheres. Several petrographic trends are also noted. Identifiable regolith material decreases with decreasing intergranular porosity while fracture porosity increases. This relative lack of maturity of regolith breccias mayreflect their generally earlier formation age an the maturity of the regolith at that earlier time

On Birthing Dancing Stars: The Need for Bounded Chaos in Information Interaction

While computers causing chaos is acommon social trope, nearly the entirety of the history of computing is dedicated to generating order. Typical interactive information retrieval tasks ask computers to support the traversal and exploration of large, complex information spaces. The implicit assumption is that they are to support users in simplifying the complexity (i.e. in creating order from chaos). But for some types of task, particularly those that involve the creative application or synthesis of knowledge or the creation of new knowledge, this assumption may be incorrect. It is increasingly evident that perfect order—and the systems we create with it—support highly-structured information tasks well, but provide poor support for less-structured tasks.We need digital information environments that help create a little more chaos from order to spark creative thinking and knowledge creation. This paper argues for the need for information systems that offerwhat we term ‘bounded chaos’, and offers research directions that may support the creation of such interface

Take Me Out: Space and Place in Library Interactions

Information interactions are strongly affected by the place where they occur. Specific locations are ofen associated with searches on particular topics, and individual users perform different tasks in habituated places. A classic example of habituated space is the commuter who regularly reads the news on the train. This paper investigates these associations through four user studies that examine different uses of place in information interaction. Through this, we reveal the ways in which the location of information interactions makes them effective or ineffective. This extends our interpretation of the role of place in information interaction beyond established foci such as location-based search

Identification of solar nebula condensates in interplanetary dust particles and unequilibrated ordinary chondrites

Orthopyroxene and olivine grains, low in FeO, but containing MnO contents up to 5 wt percent were found in interplanetary dust particles (IDP) collected in the stratosphere. The majority of olivines and pyroxenes in meteorites contain less than 0.5 wt percent MnO. Orthopyroxenes and olivines high in Mn and low in FeO have only been reported from a single coarse grained chondrule rim in the Allende meteorite and from a Tieschitz matrix augite grain. The bulk MnO contents of the extraterrestrial dust particles with high MnO olivines and pyroxenes are close to CI chondrite abundances. High MnO, low FeO olivines and orthopyroxenes were also found in the matrix of Semarkona, an unequilibrated ordinary chondrite. This may indicate a related origin for minerals in extraterrestrial dust particles and in the matrix of unequilibrated ordinary chondrites

Strongly interacting bosons in a disordered optical lattice

Disorder, prevalent in nature, is intimately involved in such spectacular effects as the fractional quantum Hall effect and vortex pinning in type-II superconductors. Understanding the role of disorder is therefore of fundamental interest to materials research and condensed matter physics. Universal behavior, such as Anderson localization, in disordered non-interacting systems is well understood. But, the effects of disorder combined with strong interactions remains an outstanding challenge to theory. Here, we experimentally probe a paradigm for disordered, strongly-correlated bosonic systems-the disordered Bose-Hubbard (DBH) model-using a Bose-Einstein condensate (BEC) of ultra-cold atoms trapped in a completely characterized disordered optical lattice. We determine that disorder suppresses condensate fraction for superfluid (SF) or coexisting SF and Mott insulator (MI) phases by independently varying the disorder strength and the ratio of tunneling to interaction energy. In the future, these results can constrain theories of the DBH model and be extended to study disorder for strongly-correlated fermionic particles.Comment: 15 pages, 4 figures updated to correct errors in referencing previous wor

Geochemistry of HASP, VLT, and other glasses from double drive tube 79001/2

The Apollo 17 double drive tube 79001/2 (station 9, Van Serg Crater) is distinctive because of its extreme maturity, abundance, and variety of glass clasts. It contains mare glasses of both high Ti and very low Ti (VLT) compositions, and highland glasses of all compositions common in lunar regolith samples: highland basalt (feldspathic; Al2O3 greater than 23 wt percent), KREEP (Al2O3 less than 23 wt percent, K2O greater than 0.25 wt percent), and low-K Fra Mauro (LKFM; Al2O3 less than 23 wt percent, K2O less than 0.25 wt percent). It also contains rare specimens of high-alumina, silica-poor (HASP), and ultra Mg glasses. HASP glasses contain insufficient SiO2 to permit the calculation of a standard norm, and are thought to be the product of volatilization during impact melting. They have been studied by electron microprobe major-element analysis techniques but have not previously been analyzed for trace elements. The samples analyzed for this study were polished grain mounts of the 90-160 micron fraction of four sieved samples from the 79001/2 core (depth range 2.3-11.5 cm). A total of 80 glasses were analyzed by SEM/EDS and electron microprobe, and a subset of 33 of the glasses, representing a wide range of compositional types, was chosen for high-sensitivity INAA. A microdrilling device removed disks (mostly 50-100 micron diameter, weighing approx. 0.1-0.5 micro-g) for INAA. Preliminary data reported here are based only on short counts done within two weeks of irradiation

Getting creative in everyday life: Investigating arts and crafts hobbyists' information behavior

While there has been increasing interest in how creative professionals find information to drive creative outputs, previous information behavior research has largely ignored how arts and crafts hobbyists look for information sources in their everyday lives. To fill this literature gap, we conducted interviews and observations with arts and crafts hobbyists to find out how they conceive potential DIY projects. The findings highlight three themes: the dearth of human sources, the prevalence of domain-specific information, and the use of self-curated information. In addition to empirical results, this work also broadens the understanding of information behavior in an arts and crafts context by studying populations beyond professional artists

Analytical electron microscopy of fine-grained phases in primitive interplanetary dust particles and carbonaceous chondrites

In order to describe the total mineralogical diversity within primitive extraterrestrial materials, individual interplanetary dust particles (IDPs) collected from the stratosphere as part of the JSC Cosmic Dust Curatorial Program were analyzed using a variety of AEM techniques. Identification of over 250 individual grains within one chondritic porous (CP) IDP shows that most phases could be formed by low temperature processes and that heating of the IDP during atmospheric entry is minimal and less than 600 C. In a review of the mineralogy of IDPs, it was suggested that the occurrence of other silicates such as enstatite whiskers is consistent with the formation in an early turbulent period of the solar nebula. Experimental confirmation of fundamental chemical and physical processes in a stellar environment, such as vapor phase condensation, nucleation, and growth by annealing, is an important aspect of astrophysical models for the evolution of the Solar System. A detailed comparison of chondritic IDP and carbonaceous chondrite mineralogies shows significant differences between the types of silicate minerals as well as the predominant oxides

Siderophilic Cyanobacteria for the Development of Extraterrestrial Photoautotrophic Biotechnologies

In-situ production of consumables (mainly oxygen) using local resources (In-Situ Resource Utilization-ISRU) will significantly facilitate current plans for human exploration and settlement of the solar system, starting with the Moon. With few exceptions, nearly all technologies developed to date have employed an approach based on inorganic chemistry. None of these technologies include concepts for integrating the ISRU system with a bioregenerative life support system and a food production system. Therefore, a new concept based on the cultivation of cyanobacteria (CB) in semi-closed biogeoreactor, linking ISRU, a biological life support system, and food production, has been proposed. The key feature of the biogeoreactor is to use lithotrophic CB to extract many needed elements such as Fe directly from the dissolved regolith and direct them to any technological loop at an extraterrestrial outpost. Our studies showed that siderophilic (Fe-loving) CB are capable to corrode lunar regolith stimulants because they secrete chelating agents and can tolerate [Fe] up to 1 mM. However, lunar and Martian environments are very hostile (very high UV and gamma-radiation, extreme temperatures, deficit of water). Thus, the selection of CB species with high potential for extraterrestrial biotechnologies that may be utilized in 15 years must be sponsored by NASA as soon as possible. The study of the genomes of candidate CB species and the metagenomes of the terrestrial environments which they inhabit is critical to make this decision. Here we provide preliminary results about peculiarities of the genomes of siderophilic CB revealed by analyzing the genome of siderophilic cyanobacterium JSC-1 and the metagenome of iron depositing hot spring (IDHS) Chocolate Pots (Yellowstone National Park, Wyoming, USA). It has been found that IDHS are richer with ferrous iron than the majority of hot springs around the world. Fe2+ is known to increase the magnitude of oxidative stress in prokaryotes through so called Fenton reaction. It is not surprising therefore that the CB inhabiting IDHS have larger sets of the proteins involved in the maintenance of Fe homeostasis and oxidative stress protection than non-siderophilic CB. This finding combined with our earlier results about the ability of some siderophilic CB to utilize chemical elements released from analogs of lunar and Martian regolith make them the most advanced candidates to be employed in advanced extraterrestrial biotechnologies