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Hawaii Astrobiology - Winter School Details

Winter School

UH Lead Team

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Water on Earth and in Space - January 10-21, 2005

  • Water Ice and Chemistry in Circumstellar Disks and the Interstellar Medium
    Cecilia Ceccarelli (Laboratoire d'Astrophysique, Grenoble, France)

    The interstellar medium contains the basic material out of which stars and new planetary systems form. In the cold environment of dense interstellar clouds, volatile molecules freeze out onto dust grains and form icy mantles surrounding the silicate and carbonaceous cores. Grain surface chemistry allows for the formation of more complex molecules than is possible in the gas phase. These molecules, including water, are then liberated from the grain surfaces through heating by a young star. Determining the solid state processes in dense clouds is thus essential for an understanding of the chemistry and evolution of water ice. Observationally, there are three closely related approaches to explore the role of water ice in the star formation process. The first aims to quantify the presence of water ice in the interstellar clouds, out of which stars form. The second aims to understand the structure, kinematics, composition, and physical properties of the circumstellar disks out of which planets form, thus defining the general environment in which water will exist. The third aims to determine the specific role of water ice in these chemical and physical processes. We will discuss each of these approaches in detail during this lecture series.

  • Geochemical Processes and Microbiospheres in Hydrothermal Systems
    Jim Cowen (Department of Oceanography, Honolulu, USA)

    Volcanic and hydrothermal processes associated with the global mid ocean ridge (MOR) system support potentially vast, complex ecosystems on and beneath the deep ocean floor. Subseafloor volcanic ecosystems may represent both the origin of life and/or its early evolutionon Earth and a model for exploration for life on other planets. These sub-seafloor ecosystems are linked to, and a consequence of, the flow of energy and material from Earth's deep mantle, through the volcanic and hydrothermal systems of the oceanic basement, to the deep ocean. Furthermore, the aging ocean basement that extends from the MORs to the ridge flanks, ocean basins and ultimately to the subduction zones represents a continuum of environments, which in turn may host potential biospheres varying tremendously in both intensity and nature (e.g., metabolic diversity) of activity. The linkages between life and planetary processes within this continuum of environments will be examined through discussions of a broad range of disciplines in geophysics, geology, chemistry, biology and oceanography. Discussions will progress from a general description of MOR systems to ultimately focus on several dynamic habitats that represent the physical and geochemical diversity of subsurface hydrothermal systems: near-field MORs (vent field); sediment-buried aging basement (ridge flanks); serpentization-influenced mud-volcanoes.

  • Glaciers on Earth, Mars, and Europa
    Thorsteinn Thorsteinnson (National Energy Authority, Reykjavik, Iceland)

    At present, ice covers about 10% of the Earth's land surface, but the past 2.5 million years have been characterized by the repeated growth and decay of continental ice sheets in response to orbitally-driven climate changes. A wealth of information on these past variations in climate and atmospheric composition has been retrieved from deep ice cores drilled on the Greenland and Antarctic ice sheets. Smaller ice caps and mountain glaciers around the world are sensitive indicators of current atmospheric warming trends and their study also yields information on the dynamics and physical properties of natural ice masses. In this lecture series, we will first present a general overview of the science of glaciology, focusing on the internal structure of glaciers and ice sheets, and on ice-core studies of climate-related changes in the concentrations of oxygen and hydrogen isotopes. In the astrobiological context, we will learn about studies of life in icy environments on Earth, with special focus on subglacial lakes in Antarctica and Iceland. This will be followed by a discussion of the polar ice caps and ground ice on Mars, with emphasis on the possible occurrence of liquid water beneath the surface of the planet. Finally, we will discuss the possibilities of life thriving in the ocean believed to exist beneath the icy shell of Jupiter's moon Europa.

  • Icy Bodies in the Solar System and the Origin of the Earth's Oceans
    Karen Meech (Institute for Astronomy, Honolulu, USA)

    Comets are the primordial remnants from the era in the solar system when the planets were accumulating. Forming at a range of distances from the young sun, out in the vicinity of the giant planets, comets contain a record of the chemistry and physics within the solar nebula. Comets and other planetesimals forming closer to the sun were part of a large flux of impactors which interacted with the early Earth, bringing both water and organics to our planet. In this lecture strand, we will investigate the properties of comets, learn about ice physics and what this tells us about the early solar system and the connection to the interstellar material out of which the comets formed. In addition, we will examine the controversies surrounding how much of the Earth's oceans were delivered by comets, by investigating the issues surrounding the D/H ratio in comets and on Earth (and the other terrestrial planets). Discussions will also include comet observing techniques as well as some of the latest laboratory experiments on low density ices, and the exciting experimental cometary science to be undertaken with the NASA Deep Impact mission.

Last modified: December 28, 2004
Karen Meech
Institute for Astronomy
2680 Woodlawn Drive
Honolulu, HI 96822
808-956-6828 voice, 808-956-9580 fax
meech@ifa.hawaii.edu