ALBERT

Description: Seeking the signs of life on Mars is often considered the "first among equal" objectives for any potential Mars Sample Return (MSR) campaign. Among the geological settings considered to have the greatest potential for recording evidence of ancient life or its pre-biotic chemistry on Mars are lacustrine (and marine, if ever present) sedimentary depositional environments. This potential, and the possibility of returning samples that could meaningfully address this objective, have been greatly enhanced by investigations of an ancient redox stratified lake system in Gale crater by the Curiosity rover.

Description: Highly promising locales for biosignature prospecting on Mars are ancient hydrothermal deposits, formed by the interaction of surface water with heat from volcanism or impacts. On Earth, they occur throughout the geological record (to at least approx. 3.5 Ga), preserving robust mineralogical, textural and compositional evidence of thermophilic microbial activity. Hydrothermal systems were likely present early in Mars' history, including at two of the three finalist candidate landing sites for M2020, Columbia Hills and NE Syrtis Major. Hydrothermal environments on Earth's surface are varied, constituting subaerial hot spring aprons, mounds and fumaroles; shallow to deep-sea hydrothermal vents (black and white smokers); and vent mounds and hot-spring discharges in lacustrine and fluvial settings. Biological information can be preserved by rapid, spring-sourced mineral precipitation, but also could be altered or destroyed by postdepositional events. Thus, field observations need to be followed by detailed laboratory analysis to verify potential biosignatures. See Attachment

Description: August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged citizen scientists and students in an investigation of the effects of an eclipse on the mid-latitude ionosphere. Activities included fieldwork and station-based data collection of HF Amateur Radio frequency bands and VLF radio waves before, during, and after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse.

Description: We report MMS observations of the ion-scale flux transfer events (FTEs) that may involve two main X lines and tearing instability between the two X lines. The four spacecraft detected multiple isolated regions with enhanced magnetic field strength and bipolar B(sub )n signatures normal to the nominal magnetopause, indicating FTEs. The currents within the FTEs flow mostly parallel to B, and the magnetic tension force is balanced by the total pressure gradient force. During these events, the plasma bulk flow velocity was directed southward. Detailed analysis of the magnetic and electric field and plasma moments variations suggests that the FTEs were initially embedded within the exhaust region north of an X line but were later located southward/downstream of a subsequent X line. The cross sections of the individual FTEs are in the range of ~2.5-6.8 ion inertial lengths. The observations suggest the formation of multiple secondary FTEs. The presence of an X line in the exhaust region southward of a second X line results from the southward drift of an old X line and the reformation of a new X line. The current layer between the two X lines is unstable to the tearing instability, generating multiple ion-scale flux-rope-type secondary islands.

Description: For over five decades of manned spaceflight missions, NASA astronauts have taken extraordinary photographs of Earth's surface and dynamic processes. Humans on board the International Space Station (ISS) have a unique platform to perform Earth observations at various viewing angles, seasons, and times of day. Astronaut photos taken from the ISS comprise a truecolor (RGB) dataset taken with multiple handheld digital cameras and lens types (prior to 2004, film cameras were in use). Earth observations through astronaut photography are an important and unique remote sensing method when monitoring natural disasters, urban growth, and environmental changes. While astronaut imagery can be used for earth science research, there is also an artistic aspect to the photography that fascinates a wide global population. A broader public audience can be introduced to earth science through high resolution, Earth art photos taken from the perspective of an astronaut. The Crew Earth Observations (CEO) Facility within the Earth Science and Remote Sensing Unit at NASA's Johnson Space Center supports the acquisition, analysis, and curation of astronaut photography of Earth's surface and atmosphere. CEO's website, the Gateway to Astronaut Photography of Earth (eol.jsc.nasa.gov), provides free public access to view, search, and download over three million images taken by astronauts throughout all of NASA's crewed spaceflight history, with an emphasis on current ISS imagery. The CEO Facility actively curates a digital collection of exceptional Earth art astronaut photos used for public engagement. Our new Downloadable Earth Art page focuses on broad earth science topics including: mountains, water, clouds, agriculture, as well as an "abstract" category. This continuouslyupdated collection is comprised of freely accessible and highquality downloadable materials, such as single and dualscreen digital wallpapers. All Earth Art materials are presented with sciencebased information that complements the artistic qualities of the imagery, and facilitate connections between general audiences and earth science from the International Space Station.

Description: Clean room standards like ISO 14644 used for facilities that construct spacecraft and store returned samples do not explicitly account for microbial contamination. While there are associated ISO standards for monitoring and controlling bio-contamination in clean rooms it is not always standard practice to do so. The NASA Astromaterials Acquisition and Curation Office maintains seven separate clean labs for storing extraterrestrial samples from the Moon, meteorites, cosmic dust, asteroids, comets, solar wind particles, and microparticle impact samples. These labs are routinely monitored for particulate and trace metal contamination. However, the sample collections are either non-sterile at the time of collection (e.g., meteorites) or are no longer being used to address scientific questions that could be affected by non-sterile conditions (e.g., Lunar samples). Outside of isolated studies there has not been a systematic, longitudinal characterization of the microbial ecology of NASA curation clean rooms. In accordance with the advanced curation initiative, and to prepare for future sample return missions, we have initiated a routine microbiological monitoring program in the Antarctic Meteorite Lab. This monitoring program will be used to determine what microbes are capable of surviving in these oligotrophic environments and whether or not they are capable of altering the sample collections in any significant manner. Repeat sampling will allow us to understand how routine use of these labs affects the microbial ecology over time.

Description: We present a community-led assessment of the solar system investigations achievable with NASA's next-generation space telescope, the Wide Field Infrared Survey Telescope (WFIRST). WFIRST will provide imaging, spectroscopic, and coronagraphic capabilities from 0.43 to 2.0 m and will be a potential contemporary and eventual successor to the James Webb Space Telescope (JWST). Surveys of irregular satellites and minor bodies are where WFIRST will excel with its 0.28 deg2 field-of-view Wide Field Instrument. Potential ground- breaking discoveries from WFIRST could include detection of the first minor bodies orbiting in the inner Oort Cloud, identification of additional Earth Trojan asteroids, and the discovery and characterization of asteroid binary systems similar to Ida/Dactyl. Additional investigations into asteroids, giant planet satellites, Trojan asteroids, Centaurs, Kuiper belt objects, and comets are presented. Previous use of astrophysics assets for solar system science and synergies between WFIRST, Large Synoptic Survey Telescope, JWST, and the proposed Near-Earth Object Camera mission is discussed. We also present the case for implementation of moving target tracking, a feature that will benefit from the heritage of JWST and enable a broader range of solar system observations.

Description: There are many challenges involved in deep-space exploration, but several of these can be mitigated, or even solved, by the development of a coating that reflects most of the Suns energy, yet still provides far-infrared heat emission. Such a coating would allow non-heat-generating objects in space to reach cryogenic temperatures without using an active cooling system. This would benefit deep-space sensors that require low temperatures, such as the James Webb Telescope focal plane array. It would also allow the use of superconductors in deep space, which could lead to magnetic energy storage rings, lossless power delivery, or perhaps a large-volume magnetic shield against galactic cosmic radiation. However, perhaps the most significant enablement achieved from such a coating would be the long-term, deep space storage of cryogenic liquids, such as liquid oxygen (LOX). In our Phase I NIAC study, we realized that a combination of scattering particles and a silver backing could yield a highly effective, very broadband, reflector that could potentially reflect more than 99.9% of the Suns irradiant power. We developed a sophisticated model of this reflector and theoretically showed that cryogenic temperatures could be achieved in deep space at one astronomical unit (1 AU) from the Sun. We showed how this new reflector could minimize heat conduction into the cryogenic tanks by coating the tank support struts. We then modelled a strawman architecture for a mission to Mars, using a coated LOX tank, coated struts, and infrared shields, to show that with our new coating it would be possible to maintain liquid oxygen passively. As a result of this work a patent application was generated and a paper published in Optics Letters. Our Phase II NIAC study had two primary goals, to develop a rigid version of the cryogenic selective surface proposed in Phase I and to test its performance in a simulated deep space environment. During the first year of the project the work concentrated on developing rigid tiles of BaF2, leading to tiles as large as 4 inches in diameter that transmitted very little visible light. In addition, during the first year a simulated deep space environment was created using a vacuum chamber and cryocooler. Using this facility, we showed that our BaF2 tiles absorbed less than % of 375 nm radiation, a significant milestone for the work. During the second year of the project, we continued to develop the BaF2 tiles and we put significant effort into the construction of a deep space environment where we could project simulated solar radiation onto a sample. In the spring of 2018, we conducted our first solar simulator test with BaF2 and saw about 3.6% absorption. This is better than the state-of-the-art, but disappointing since predictions were for much lower absorption. We, erroneously, attributed this absorption to water retention by the BaF2, and decided to change materials. We considered several oxides and settled on yttrium oxide (Y2O3) for further development, because it is broadband, lightweight, has high index, and is hydrophobic. In July 2018 we conducted our first test of a rigid tile of Y2O3 in the simulated deep space environment and saw significant absorption again. We then realized that the issue was not water, but mid-wave radiation passing through the tile and being absorbed by the temperature sensor and the varnish used to hold it in place. We wrapped the sensor in silver foil, re-ran the test, and saw much lower absorption; only 1.1%. We then re-ran the BaF2 tile and saw 1.4% absorption. These values are almost adequate to maintain LOX in deep space, but we suspect that there are still issues in our test apparatus; we suspect thermocouple wires may be absorbing radiation. Further, post-NIAC, testing will better determine the performance of our new solar reflector. In order to restrict the size of this report, we will only briefly describe topics that we have previously published, allowing us to devote more time to new material. So minimal material will be devoted to modeling the material and deep space cryogenic storage, while longer sections will cover our material development, simulated deep space testing, and new applications. The Launch Service Program (LSP) requested that we explore ways to use this new coating to maintain LOX in low Earth Orbit and that work is described. In addition, the Nuclear Thermal Propulsion (NTP) Program asked us to explore ways to reduce the heat load for liquid hydrogen, resulting in the development of a spray-on version of the coating that should significantly improve in-space multi-layer insulation performance.

Description: The relation of two well-known ancient carbonate deposits to hydrocarbon seepage was confirmed by this study. Archaea are found to be associated with the formation of Oxfordian seep carbonates from Beauvoisin and with a Miocene limestone from Marmorito ("tube-worm limestone"). Carbonates formed due to a mediation by archaea exhibit extremely positive or extremely negative 813Ccarbonate values, respectively. Highly positive values (+ 15%0) reflect the use of 13C-enriched CO2 produced by methanogenesis. Low 813C values of the Marmorito carbonates (-30%0) indicate the oxidation of seepagederived hydrocarbons. Likewise, the 813C content of specific tail-to-tail linked isoprenoids, biomarkers for archaea, was found to be strikingly depleted in these sampies (as low as -115%0). The isotopic signatures corroborate that archaea were involved in the cycling of seepage-derived organic carbon at the ancient localities. Another Miocene limestone ("Marmorito li mestone") shows a strong imprint of methanotrophic bacteria as indicated by 813C va lues of carbonate as low J. Peckmann (IEI) . J. Reitner Institut und Museum für Geologie und Paläontologie, Georg-August-Universität. Goldschmidtstrasse 3, D-37077 Göttingen, Germany e-mail: jpeckma@gwdg.de. Fax: + 49-551-397918 V. Thiel, W. Michaelis Institut für Biogeochemie und Meereschemie, Universität Hamburg, Bundesstrasse 55, D-20146 Hamburg, Germany P. Clari, L. Martire Dipartimento di Scienze della Terra, via Accademia delle Scienze 5, 1-10123 Torino, Italy C. Gaillard UFR des Sciences de la Terre, UMR 5565 Centre de Paleontologie stratigraphique et Paleoecologie, Universite Claude Bemard, Lyon 1, 27-43 Boulevard du 11 Novembre, F-69622 Villeurbanne Cedex, France as -40%0 and biomarker evidence. Epifluorescence microscopy and field-emission scanning electron microscopy revealed that bacterial biofilms were involved in carbonate aggregation. In addition to lucinid bivalves previously reported from both localities, we infer that sponges from Beauvoisin and tube worms from Marmorito depended on chemosynthesis as weil. Low 813C values of nodules related to sponge taphonomy (-27%0) indicate that sponges might have been Iinked to an enhanced hydrocarbon oxidation. Tube worm fossils from Marmorito closely resemble chemosynthetic pogonophoran tube worms from Recent cold seeps and are embedded in isotopically light carbonate (813C -300/00).

Description: The duration and position of the Rhaetian Stage are di scussed. With the recognition of Rhabdoceras suessi - up to now the index species of the Upper Norian (Sevatian) - in one of the Alpine type sections of the Rhaetian, this Stage becomes more and more restricted and its separation doubtfu!. Four possibilities for defining the Alpine uppermost Triassic are treated. The authors propose either to redefine the Alpi'ne Rhaetian as the uppermost Substage of thc Norian Stage, thereby replacing the Sevatian (proposal 4), or to include the previous Sevatian into an enlarged Rhaetian Stage (proposal 3). This proposal is favoured by the International Subcommission of Triassic Stratigraphy. Ir is supported by the recent discovery of Choristoceras marshi - index species of the restricted Rhaetian - in the lower part of the Koessen Beds of the Lahnewiesgraben, equivalent to the previous Zone of Rhabdoceras suessi. Ir is moreover supported by the discovery of the immediate ancestor of this species in the upper part of the Middle Norian (Alaunian) of Timor. This makes the suessi Zone synonymous with the marshi Zone, the lower part of wh ich may be treated now as the Subzone of Rhabdoceras suessi. Since no particular ammonite species can be used for defining the upper part, this can be defined only by the exclusive occurrence of Choristoceras marshi without Rhabdoceras messi. As reference section of the redefined Rhaetian Stage the Weißloferbach section near Koessen, Tirol (Austria) is proposed, since it is weil exposed and fossiliferous, bearing cephalopods, bivalves, brachiopods, ostracods, conodonts and other groups. The authors propose moreover to redefine and re-name the "Rhaetian" of the Germanic facies Realm, which can by no means bc correlated with the Alpine Realm. The names "Upper Keuper" or "Rhaetkeuper" may be more adequate. There is, however, some palynological evidence for a correlation of the Germanie Preplanorbis Beds with the Alpine "Schichtenfolge unter Anm. planorbis" in SUESS & MOJSISOVICS (1868), where Choristaceras marshi has disappeared. The occurrence of the first psiloceratid (Neophyllites antecedens) in these beds indicates that they represent the base of the Jur~sic System. Provisionally these Preplanorbis Beds remain included into the Zone of Psiloceras planorbis.

Description: Umfang und Stellung des Rhaet werden erörtert. Nach dem Fund von Rhabdoceras suessi - bislang Zonen-Art des Oberen Nor (Sevat) - in einem der alpinen Typprofile des Rhaet, ist der Umfang der Stufe erheblich geschrumpft und ihre Definition problematisch geworden. Von den Verf. werden vier Möglichkeiten, die höchste Trias zu definieren, zur Diskussion gestellt. Es wird empfohlen, entweder das alpine Rhaet als oberste Unterstufe des Nor neu zu definieren und das Sevat einzubeziehen (Vorschlag 4) oder aber das Rhaet - gleichfalls unter Einbeziehung des Sevat - als selbständige Obertrias-Stufe fortbestehen zu lassen (Vorschlag 3). Dieser Vorschlag wurde von der Internationalen Subkommission für Trias-Stratigraphie eindeutig favorisiert. Er wird durch den lange erwarteten Fund von Choristaceras marshi im tieferen Teil der Koessener Schichten des Lahnewiesgraben unterstützt, der stratigraphisch der bisherigen suessi-Zone entspricht. Nach der Entdeckung von direkten marshi-Vorläufern im oberen Mittelnor (Alaun, columbianus-Zone) von Timor sind diese Neufunde nicht mehr überraschend. Damit würde das neudefinierte Rhaet zwar wiederum nur die Zone des Choristoceras marshi enthalten, definiert durch das Erstauftreten dieser Art; es wäre aber eine Untergliederung in eine Subzone des Rhabdoceras suessi und eine obere Subzone des Choristoceras marshi s. str. (ohne Rh.suessi) möglich. Dieser Vorschlag ist der praktikabelste und schließt sich am engsten an die bisherigen Gepflogenheiten an. In dieser Form würde das Rhaet nun auch eine durchaus kartierfähige Einheit darstellen. Als Referenzprofil für das erweiterte Rhaet wird das Profil am Weißloferbach bei Koessen, Tirol (Osterreich) empfohlen, das nicht nur gute Aufschlußverhältnisse, sondern auch eine diverse Faunenvergesellschaftung enthält (Cephalopoden, Bivalven, Brachiopoden, Ostracoden, Conodonten u. a.). Es wird außerdem empfohlen, das germanische Rhaet neu zu definieren und zu benennen, da eine direkte Korrelation mit dem alpinen Rhaet nicht möglich ist. Die Begriffe "Oberkeuper" oder "Rhaetkeuper" werden zur Diskussion gestellt. Die Palynologie bietet erste Korrelationsmöglichkeiten, insbesondere für die hangenden Praeplanorbis- Schichten der germanischen Fazies, die mit der alpinen "Schichtenfolge unter Amm. planorbis" (SUESS & MOJSISOVICS 1868) parallelisiert werden können. Hier tritt Choristoceras marshi nicht mehr, Psiloceras plallorbis noch nicht auf. Mit dem ersten Einsetzen echter Psiloceraten (Neophyllites antecedcns) dürfen diese Schichten als Basis des Lias angesehen werden. Vorläufig bleiben sie jedoch in die Zone des Psiloceras planorbis des Unteren Hettangs eingeschlossen. Trotz des deutlichen Ausdünnens der Ammonitenführung in der obersten Trias - im Zusammenhang mit dem triadisch/ liassischen Faunenschnitt - soll die primäre "orthochronologische" Gliederung dieses Zeitraums auch weiterhin auf der Grundlage der Ammoniten-Fauna erfolgen. Sie wird allerdings wesentlich durch die bereits verfeinerte Conodonten-Gliederung ergänzt; die biostratigraphischen Möglichkeiten des Nannnoplanktons werden augenblicklich überprüft. Ein wesentliches Hilfsmittel für die Parallelisierung von germanischer und alpiner Fazies stellt sdlon jetzt die Palynologie dar, obwohl hier erst wenige vergleichende Untersuchungen vorliegen. Die Konferenz der lUGS "Subcommission on Trias Stratigraphy", welche vom 3.- 4. Juli 1978 in München stattfand, und an die sich ein 3-tägiger Field Workshop anschloß, sollte einen Beitrag leisten zur Korrelation zwischen der Trias im Tethysbereich und der Germanischen Trias-Fazies. G. RrcHTER-BERNBURG, der derzeitge Chairman der S. T. S., hatte als besonders wichtiges Teilproblem die Stellung und Abgrenzung des Rh a e t benannt. Nach gemeinsamer Absprache wird nun hiermit eine Stellungnahme kompetenter Kollegen zu dieser Frage, gemeinsam mit einem An- hand aus palynologischer Sicht, vorgelegt. In einem "Nachwort" werden vom Chairman einige zusätzliche Bemerkungen sowie eine von der S. T. S. gefaßte Resolution zum Begriff Rhaet angefügt. Während die Mehrzahl der Autoren dieses Beitrags dem Abstimmungsergebnis beipflichtet, ist für einen der Autoren (LK) nach wie vor nur Vorschlag 4 (Tab. 2) annehmbar.