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2013 Annual Science Report

University of Hawaii, Manoa Reporting  |  SEP 2012 – AUG 2013

Executive Summary

There is no executive summary for this team at this time.

Field Sites
27 Institutions
9 Project Reports
99 Publications
20 Field Sites

Project Reports

  • Star Formation and the Variable Young Stellar Objects Survey

    Planets form in circumstellar disks around young stars in the early stage of star formation and the physical, chemical, and kinematic properties of young stellar objects set the initial conditions of planet formation and affect subsequent evolution of protostars and planets. In this project we perform optical and submillimeter observations to study young stellar objects. In the optical wave-lengths, the Variable Young Stellar Objects Survey (VYSOS) aims at surveying all the major star forming regions visible from Hawaii for variable young stars. A small survey telescope provides shallow observations over a large area of the sky, and a larger telescope allows deeper more detailed observations of smaller regions. VYSOS observations are done robotically. In the submillimeter wave-lengths, high resolution interferometric observations combined with radiative transfer modeling reveal structures of protostellar envelopes and resolve the embedded disks. We also study the spatial distributions of a deuterated molecule relative to its hydrogenbearing counterpart in the envelopes and compare to chemical models. Lastly, brown dwarf triple systems are studied via numerical simulations, and the results show that when such triple systems break up during the protostellar phase, a common result is the formation of a brown dwarf binary.

  • Ice Chemistry: Radiation Induced Chemical Processing

    Prebiotic molecules such as amino acids, sugar, and sugar alcohols are thought to be delivered to the early Earth by meteorites and comets and may have played crucial role in the origin of life. However, there is no conclusive evidence of these molecules found in the interstellar medium. However, simple precursors such as formaldehyde, acetaldehyde, acetone, propanal, propenal, and acetic acid were observed in the interstellar medium such as toward the star forming region SgrB2. Extraterrestrial ices with abundant molecules like water, methane, carbon monoxide, carbon dioxide, ammonia, and methanol are exposed to ionizing radiation such as galactic cosmic radiation and UV radiation. Here, we have been investigating the effect of ionizing radiation on simple astrophysical ice representatives in the solid state using FTIR, UV-VIS, Raman spectroscopy as well as the products analyzed in the gas phase (fragment free reflectron time-of-flight mass spectroscopy combined with single photon ionization (ReTOF-PI)) while subliming to the gas phase after a controlled temperature desorption. Our laboratory simulation experiments provide clear evidence of the formation of large number of aldehydes, ketones such as acetaldehyde, acetone in methane-carbon monoxide ices, formation of simple sugar alcohols (glycerol) in methanol ices and possibly formation of amino acid (glycine) in mixed ices of water, carbon dioxide, methane, and ammonia.

  • Subsurface Exploration for Astrobiology: Oceanic Basaltic Basement Biosphere

    While extraterrestrial life is likely to exist within the subsurface of water-occupied objects such as Enceladus and Europa, the continued investigation of the subsurface biosphere on the earth provides important insight and implications for astrobiology. This research investigates a deep sub-seafloor basement biosphere. At the ocean floor, lying underneath an often times thick layer of sediment is hard basaltic rock, or basement. Seawater enters the basement and circulates within. It is now known that low temperature hydrothermal fluids (<100oC) circulate everywhere within the porous and permeable volcanic rocks of the upper ocean basement, providing temperature and chemical gradients that host extensive alteration of basement rocks and fluids and form plausible habitats for microbial life. While microbial activity has been observed in deeply buried sediments and exposed basement rock, few direct tests have been carried out in deep subseafloor basement rocks or fluids. A majority of the crustal hydrothermal flow and seawater-crustal fluid exchange, and the corresponding advective heat and mass output, occurs on the flanks of the mid-ocean ridge with basement ages of >1 million years old. This low-temperature ridge flank flow rivals the discharge of all rivers to the ocean and is about three orders of magnitude greater than the high temperature discharge at mid-ocean ridges. The resulting ridge flank chemical flux impacts ocean biogeochemical cycles and may sustain deep basement microbial communities. Access to uncontaminated fluids from subseafloor basement is problematic, especially where ridge flanks and ocean basins are buried under thick, impermeable layers of sediment (i.e., thick enough to act as a barrier to rapid exchange of fluids). We rely on custom designed instrumentation to collect large volume high integrity basement fluids, where the concentrations of microorganisms are often very low (e.g. about 1/10 of bottom seawater concentrations). By studying the chemical composition of crustal fluids, we have learned that several important energy sources, such as dissolved methane and hydrogen, are available. In addition, the isotopic signature of dissolved methane suggests that microbial production and consumption occurs in the basement environment. By filtering microbial biomass from the fluids and investigating their nucleic acids, we are investigating the evolutionary and functional characteristics of the diverse bacterial, archaeal, and viral communities that inhabit the deep subsurface of Earth. Our on-going research includes the investigation of temporal (at hourly-resolution) and spatial (at a few hundred meter scale) biogeochemical and biological variability in order to more effectively constrain our measured parameters. We are also characterizing the dissolved organic carbon pool in basement fluids to investigate the role that basement environment plays in the global carbon cycle.

    ROADMAP OBJECTIVES: 4.1 5.1 5.2 5.3 6.1 6.2
  • Origin of Earth’s Water

    Understanding the sources and delivery mechanisms of water to the Earth and the other terrestrial planets allows for the validation of planetary accretion models. This information can help us establish at what time the Earth contained sufficient water for the development of life. A key parameter in determining the source(s) of terrestrial planetary water is the hydrogen isotope composition of this water. However, hydrogen fractionation during surface and atmospheric processes on terrestrial planets such as Earth and Mars may have significantly changed the Deuterium/Hydrogen (D/H) ratio in the various water reservoirs. Therefore, to determine the primordial D/H ratio of these planets water we must find reservoirs that has been unaffected by surface processes. Plate tectonics is known to drag surface water down into the crust and the upper mantle, but the transition zone and lower mantle are thought to be uncontaminated by surface water. Therefore, we aimed to sample terrestrial hydrous minerals and melt inclusions sourced from these uncontaminated regions, such as deep mantle plume samples from Iceland and Baffin Island, along with possible deep mantle diamond inclusions. As plate tectonics never developed on Mars, the primary igneous hydrous minerals in martian meteroites were assumed to be isolated from martian surface processes. We analyzed the D/H ratio of these samples using the Cameca ims 1280 ionmicroprobe at the University of Hawaii to produce a dataset that establishes the primordial D/H ratio of Earth and Mars.

    To gain insights into the amount of water present in terrestrial planetary mantle material we synthesized samples of high-pressure mineral phases that are likely hosts for H, and thus water, in planetary interiors. We measured the physical properties of these minerals, including crystal structure, density, elasticity, and electrical conductivity, to investigate the degree to which water may be incorporated into these minerals in the Earth’s mantle.

    Models of terrestrial planet formation have been successful in producing terrestrial-class planets with sizes in the range of Venus and Earth. However, these models have generally failed to produce Mars-sized objects. The body that is usually formed around Mars’ semimajor axis is, in general, much more massive than Mars. We have developed new model for the formation of Mars in which a local depletion in the density of the protosolar nebula results in a non-uniform formation of embryos and ultimately the formation of Mars-sized planets.

  • The Nature and Timing of Aqueous Alteration in Ordinary and Carbonaceous Chondrites

    Water plays a key role in the search for life and habitable planets outside of our Solar System. However, a fundamental question remains unanswered: what is the origin of water on Earth and the terrestrial planets? Our research addresses this question by looking towards chondrites, the building blocks of the Solar System. Chondritic meteorites were assembled within a few million years after the birth of the Sun, and preserve a record of the earliest Solar System processes. We are working to constrain the origin of water in chondritic asteroids, to understand the timescales and conditions of aqueous alteration on chondritic parent bodies, and the effects of aqueous alteration on synthesis and modification of organic matter in chondrites, and to explore how water affected the geologic evolution of primitive material. This work has important implications for the amount of water accreted or delivered to the inner Solar System planets, and the synthesis and delivery of organic matter necessary for life on Earth.

  • Solar System Volatile Distributions – Icy Bodies

    One of the forefront areas of science related to the early solar system, and highlighted in the Plane-tary Decadal Survey, is the need to understand the source of volatiles for planets in the habitable zone and the role that primitive bodies played in creating habitable worlds. Comets, which have escaped the high-temperature melting and differentiation that asteroids experience, are “astrobio-logical time capsules” that have preserved a valuable record of the complex chemical and physical environment in the early solar Nebula. In the early 1970’s we were at the threshold of a new era of asteroid physical studies. After four decades the asteroid population is yielding information about compositional gradients in the nebula, aqueous alteration processes in the protoplanetary disk and the early dynamic environment as the giant planets formed. Similarly, large surveys of Kuiper belt objects have lead to a new understanding of the dynamic solar system architecture and of the outer solar system composition and collisional environment. Surveys are beginning to yield information on comet physical properties, including spectroscopic measurement of volatile comet outgassing at optical and IR wavelengths, nucleus sizes and activity from space and from the ground. As these surveys obtain small solar system body data, they enable a new science that involves studies of clas-ses, secular evolution of physical characteristics and processes. Our team is undertaking several studies to directly observe the volatiles in small bodies and the mechanisms of their activity, to dis-cover and characterize objects that may represent previously unstudied reservoirs of volatiles and to discover the interrelationships between various classes of small bodies in the context of the new dynamical solar system models.

    ROADMAP OBJECTIVES: 1.1 2.2 3.1
  • Alteration of Asteroid Surfaces, Martian Meteorites and Terrestrial Rocks

    The inner solar system is relatively dry, but recent discoveries of water ice on the Moon, the subsurface of Mars, and potentially on a small class of asteroids known as main belt comets (MBCs), has forced us to re-evaluate our understanding of the inner solar system volatile distribution. Understanding the water content in asteroids and its evolution with time will be critical to constrain the origin and evolution of water in the asteroid belt.

    Interpreting the early aqueous history of the solar system requires an understanding of the processes that alter the original materials, including secondary alteration of minerals within parent bodies, and processes termed space weathering that influence surface layers. The nakhlite group of Martian meteorites is known to contain secondary alteration minerals that formed on Mars. We studied the fine-scale mineralogy and chemistry of these alteration minerals, and compared them to terrestrial alteration minerals formed in the Antarctic. The aim of these comparisons was to determine whether conditions such as water/rock ratio, pH and temperature were similar during the formation of alteration minerals in both planetary environments. Hence, the suitability of the Antarctic as a martian analogue site was tested.

    The distribution of MBCs and asteroids with hydrated minerals provide us with a tool to constrain the position of the snow line within the asteroid belt, which has important implications for the origin and distribution of volatiles for the terrestrial planets. However we need to understand the processes that alter the surface composition to be able to interpret the observations in the context of early solar system volatile distribution. Space weathering has been largely associated with “dry” S-type asteroids and is known to decrease the absorption depths and redden the spectral slopes of their surfaces. Only recently have studies indicated that C-type asteroids experience space weathering as well. Currently there are two contrasting views of how space weathering modifies the surfaces of these asteroids. One study found that the spectral slopes become redder with age, similar to S-type asteroids, but another study found that the spectral slopes become neutral with age. This discrepancy has been attributed to sampling effects and differences in mineralogy among C-type asteroids.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1
  • Habitability, Biosignatures, and Intelligence

    Understanding the nature and distribution of habitable environments in the Universe is one of the primary goals of astrobiology. Based on the only example of life we know, we have devel-oped various concepts to predict, detect, and investigate habitability, biosignatures and intelli-gence occurrence in the near-solar environment. In particular, we are searching for water vapor in atmospheres of extrasolar planets and protoplanets, developing techniques for remote detec-tion of photosynthetic organisms on other planets, have detected a possible bio-chemistry sig-nature in Martian clays contemporary with early life on Earth, developed a comprehensive methodology and an interactive website for calculating habitable zones in binary stellar systems, expanded on definitions of habitable zones in the Milky way Galaxy, and proposed a novel ap-proach for searching extraterrestrial intelligence.

    ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1 3.2 4.1 4.2 6.2 7.1 7.2
  • Water and Habitability of Mars and the Moon and Antarctica

    Water plays an important role in shaping the crusts of the Earth and Mars, and now we know it is present inside the Moon and on its surface. We are assessing the water budgets and total inventories on the Moon and Mars by analyzing samples from these bodies.

    We also study local concentrations of water ice on the Moon, Mars, and at terrestrial analogue sites such as Antarctica and Mauna Kea, Hawaii. We are particularly interested in how local phenomena or microclimates enable ice to form and persist in areas that are otherwise free of ice, such as cold traps on the Moon, tropical craters with permafrost, and ice caves in tropical latitudes. We approach these problems with field studies, modeling, and data analysis. We also develop new instruments and exploration methods to characterize these sites. Several of the terrestrial field sites have only recently become available for scientific exploration.

    HI-SEAS (Hawaii Space Exploration Analog and Simulation, is a small habitat at a Mars analog site in the saddle area of the Island of Hawaii. It is a venue for conducting research relevant to long-duration human space exploration. We have just completed our first four-month long mission, and are preparing for three more, of four, eight and twelve months in length. The habitat is a 36’ geodesic dome, with about 1000 square feet of floor space over two stories. It is a low-impact temporary structure that can accommodate six crewmembers, and has a kitchen, a laboratory, and a flexible workspace. Although it is not airtight, the habitat does have simulated airlock, and crew-members don mockup EVA suits before going outside. The site is a disused quarry on the side of a cinder/splatter cone, surrounded by young lava fields. There is almost no human activity or plant life visible from the habitat, making it ideal for ICE (isolated/confined/extreme) research.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1 5.3 6.1 6.2 7.1