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2011 Annual Science Report

VPL at University of Washington Reporting  |  SEP 2010 – AUG 2011

Executive Summary

The Virtual Planetary Laboratory: Overview

The Virtual Planetary Laboratory is an interdisciplinary research effort focused on answering a single key question in astrobiology: If we were to find a terrestrial planet orbiting a distant star, how would we go about recognizing signs of habitability and life on that planet? This question is relevant to the search for life beyond our Solar System, and the steps towards that endeavor are outlined in NASA’s Astrobiology Roadmap Goals 1 and 7. VPL research spans many of the Roadmap objectives, but is most relevant to Objectives 1.1 (Formation and Evolution of Habitable Planets), 1.2 (Indirect and Direct Observations of Extrasolar Habitable Planets) and 7.2 (Biosignatures to be Sought in Nearby Planetary Systems).

Recent observations have brought us much closer to identifying extrasolar environments that could support life. The successful Kepler Mission has found over a ... Continue reading.

Field Sites
33 Institutions
17 Project Reports
108 Publications
2 Field Sites
Roadmap
Objectives

Project Reports

  • Evolution of Metabolism

    Our astrobiology research focus for VPL is to understand the evolution of different metabolic groups of microorganisms during the course of Earth’s history, and how the emergence of different metabolisms, such as methanogenesis, anoxic and oxygenic photosynthesis, and other anaerobic metabolisms that involve sulfur, metal, and nitrogen could effect the chemical composition of the atmosphere.

    ROADMAP OBJECTIVES: 5.1 5.3 6.2
  • The VPL Life Modules

    The Life Modules team at VPL works on developing models of how biological processes – such as photosynthesis, breathing, and decay of organic materials – work on a planetary scale. When this is combined with the work of the atmospheric and planetary modeling teams, we are able simulate how these processes impact the atmosphere and climate of a planet. This information, then, helps us understand how might be able to detect whether or not a planet has life by looking at its atmosphere and surface. The Life Modules team has engaged in previous work coupling early Earth biogeochemistry and 1D models in the VPL’s suite of planetary models. Current work now focuses on biosphere models that simulate geographic distributions of life adapted to different climate zones and capable of coupling to 3D general circulation models (GCMs). Current project areas are: 1) development of a model of land-based ecosystem dynamics suitable for coupling with GCMs and generalizable for alternative planetary parameters, and 2) coupling of an ocean biogeochemistry model to GCMs.

    ROADMAP OBJECTIVES: 1.2 6.1 6.2 7.2
  • Postdoctoral Fellow Report: Steven Mielke

    This project seeks to resolve the long-wavelength limit of oxygenic photosynthesis in order to constrain the range of extrasolar environments in which spectral signatures of biogenic oxygen might be found, and thereby guide future planet detecting and characterizing observatories.

    ROADMAP OBJECTIVES: 5.1 6.1 6.2 7.2
  • Understanding the Early Mars Environment

    By analyzing data from rovers and orbiters, we construct theoretical models to constrain the habitability of current and past Martian environments. VPL has re-analyzed data and called into question the existence of methane and ancient oceans on Mars. In additional, we have contributed to past and future NASA missions such as Phoenix lander and the Curiosity rover,

    ROADMAP OBJECTIVES: 1.1 2.1
  • Dynamical Effects on Planetary Habitability

    The Earth’s orbit is near-circular and has changed little since its formation. The Earth is also far enough away from the Sun, that the Sun’s gravity doesn’t seriously affect the Earth’s shape. However, exoplanets have been found to have orbits that are elliptical, rather than circular, and that evolve over time, changing shape and/or moving closer or further to the parent star. Many exoplanets have also been found sufficiently close to the parent star that the star can deform the planet’s shape and transfer energy to the planet in a process called tidal heating. In this VPL task we investigate how interactions between a planet’s orbit, spin axis, and tidal heating can influence our understanding of what makes a planet habitable. Scientific highlights include the finding that tidal effects could be strong enough to cause a planet to overheat and ultimately lose its ocean, that large changes in the direction of the spin-axis of a planet could potentially increase the range of distances from the star in which the planet could remain habitable, and that the Sun may have moved significant distances outward through the Galaxy during its lifetime, changing the rate of at which large bodies have hit the Earth.

    ROADMAP OBJECTIVES: 1.1 1.2 3.1 4.3
  • Delivery of Volatiles to Terrestrial Planets

    This project uses computer models and laboratory work to better understand how volatile materials that are important for life, like water, methane, and other organic molecules, are delivered to terrestrial planets. Habitable planets are too small to gravitationally trap these volatiles directly from the gas disk from which they formed, and instead they must be delivered as solids or ices at the time of the planet’s formation, or ongoing as the planet evolves. These trapped volatiles are eventually released to form our oceans and atmosphere. In this task we use computer models of planet formation and migration to understand how the asteroid belt, which is believed to be the source of the Earth’s oceans, was formed. We also use models to understand what happens to meteoritic material as it enters a planet’s atmosphere, especially where it gets deposited in the atmosphere, what happens to it chemically, and how it interacts with the light from the parent star. .

    ROADMAP OBJECTIVES: 1.1 3.1 4.1 4.3
  • Earth as an Extrasolar Planet

    Earth is the only known planet that can support life on its surface, and serves as our only example of what a habitable planet looks like. This task uses distant observations of the Earth taken from spacecraft combined with a sophisticated computer model of the Earth to understand the appearance and characteristics of a habitable planet. With our model, we can generate accurate simulations of the Earth’s brightness, color and spectrum, when viewed at different time-intervals, and from different vantage points. This year we used these simulations to understand how we might detect the presence of an ocean on an exoplanet using polarization, and the presence of a moon around a distant exoplanet using heat energy, rather than visible light.

    ROADMAP OBJECTIVES: 1.2 7.2
  • Stromatolites in the Desert: Analogs to Other Worlds

    In this task biologists go to field sites in Mexico to better understand the environmental effects on growth rates for freshwater stromatolites. Stromatolites are microbial mat communities that have the ability to calcify under certain conditions. They are believed to be an ancient form of life, that may have dominated the planet’s biosphere more than 2 billion years ago. Our work focuses on understanding these communities as a means of characterizing their metabolisms and gas outputs, for use in planetary models of ancient environments.

    ROADMAP OBJECTIVES: 4.1 4.2 5.2 5.3 6.1 6.2
  • Super-Earth Atmospheres

    In this task we use computer models to study aspects of the atmospheres of extrasolar super-Earths, planets that orbit other stars that are 2-10 times more massive than the Earth. Significant progress was made this year on two models, one that calculates how the atmosphere of the super-Earth is affected by radiative and particles coming from its parent star and one that calculates the surface temperature and change in atmospheric temperature with altitude for superEarth atmospheres.

    ROADMAP OBJECTIVES: 1.1 2.1 3.1
  • VPL Databases, Model Interfaces and the Community Tool

    The Virtual Planetary Laboratory (VPL) develops computer models of planetary environments, including planets orbiting other stars (exoplanets) and provides a collaborative framework for scientists from many disciplines to coordinate their research. As part of this framework, VPL develops easier to use interfaces to its models, so that they can be used by more researchers. We also collect and serve to the community the scientific data required as input to the models. These input data include spectra of stars, data files that tell us how atmospheric gases interact with incoming stellar radiation, and plant photosynthetic pigments. We also develop tools that allow users to search and manipulate the scientific input data.

    ROADMAP OBJECTIVES: 1.1 1.2
  • Understanding Past Earth Environments

    For much of the history Earth, life on the planet existed in an environment dramatically different than that of modern-day Earth. Thus, the ancient Earth represents a planet with a biosphere that is both dramatically different than the one in which we live and is accessible to detailed study. As such, is serves as a model for what types of biospheres we may find on other planets. A particular focus of our work was on the “Early Earth” (formation through to about 500 million years ago), a timeframe poorly represented in the geological and fossil records but comprises the majority of Earth’s history. We have studied the composition of the ancient atmosphere, modeled the effects of clouds on such a planet, studied the sulfur, oxygen and nitrogen cycles, and the atmospheric formation of molecules that were likely important to the origins of life on Earth.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 6.1
  • Astronomical Observations of Planetary Atmospheres and Exoplanets

    This task encompasses remote-sensing observations of Solar System and extrasolar planets made by the VPL team. These observations, while providing scientific exploration in its own right, also allow us to test our planetary models and help advance techniques to retrieve information from the astronomical data that we obtain. This can include improving our understanding of the accuracy of inputs into our models, such as spectral databases. This year we made and/or analyzed observations of Mars, Venus and Earth taken by ground-based and spaceborne observatories, to better understand how well we can determine planetary properties like surface temperature and atmospheric composition, when a terrestrial planet is observed only as a distant point of light.

    ROADMAP OBJECTIVES: 1.2 2.2 7.2
  • Detectability of Biosignatures

    In this project VPL team members explore the nature and detectability of biosignatures, global signs of life in the atmosphere or on the surface of a planet. This year we completed and published our work on the build up and detectability of sulfur-based biosignatures in early Earth-like atmospheres, especially for planets orbiting stars cooler than our Sun. We also continued to explore the potential non-biological generation of oxygen and ozone in early Earth-like atmospheres, which could result in a “false positives” for photosynthetic life. In parallel, we worked with three simulators for telescopes that will one day be able to observe and determine the properties of extrasolar terrestrial planets, and used these simulators to calculate the relative detectability of gases produced by life.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 7.2
  • Planetary Surface and Interior Models and SuperEarths

    We use computer models to simulate the evolution of the interior and the surface of real and hypothetical planets around other stars. Our goal is to work out what sorts of initial characteristics are most likely to contribute to making a planet habitable in the long run. Observations in our own Solar System show us that water and other essential materials are continuously consumed via weathering (and other processes) and must be replenished from the planet’s interior via volcanic activity to maintain a biosphere. The surface models we are developing will be used to predict how gases and other materials will be trapped through weathering over time. Our interior models are designed to predict how much and what sort of materials will come to a planet’s surface through volcanic activity throughout its history.

    ROADMAP OBJECTIVES: 1.1 1.2 4.1 5.2 6.1
  • Postdoctoral Fellow Report: Mark Claire

    I have studied how biology might have impacted Earth’s early atmosphere, and how the Sun’s light has changed with time. More specifically, I’ve modeled how enhanced release of biogenic sulfur gases in earlier periods of Earth history may have left clues in the geologic record, and compared these predictions to the data. Furthermore, I have made a model of what how the light from the Sun would appear at any planet or any time in the solar system.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 7.2
  • Stellar Radiative Effects on Planetary Habitability

    Habitable environments are most likely to exist in close proximity to a star, and hence a detailed and comprehensive understanding of the effect of the star on planetary habitability is crucial in the pursuit of an inhabited world. We looked at how the Sun’s brightness would have changed with time. We used models to study the effect of one very big flare on a planet with a carbon dioxide dominated atmosphere, like the early Earth’s, and found that these types of planets are well protected from the UV flux from the flaring star. We have also looked at the first quarter of Kepler data to study flare activity on “ordinary” cool stars, that have not been preselected for their tendency to have large flares. We find that these cool stars fall into two categories: stars that have long duration flares of several hours, but flare less frequently overall, and stars that have short duration flares, but more of them. In future work we will explore the comparative effect on a habitable planet of these two patterns of flaring activity.

    ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.3 7.2
  • The Long Wavelength Limit for Oxygenic Photosynthesis

    Photosynthesis is process where plants and bacteria use solar energy to produce sugar and oxygen. It is also the only known process that produces signs of life (biosignatures) on a planetary scale. And, because starlight (or solar energy) is one of the most common sources of energy, it is expected that photosynthesis will be successful on habitable extrasolar planets. Our team is studying how photosynthetic pigments – the molecules that make photosynthesis possible – might function in unique or extreme environments on other planets. In our experiments, we use a bacteria called Acaryochloris marina to study how different photosynthetic pigments work. This bacterium is useful for our research because it uses a pigment known as chlorophyll d instead of chlorophyll a, which is more common on our planet. Chrolophyll a works well in Earth’s environment but, by studying chlorophyll d, we can begin to understand how photosynthesis might work on planets with different environments than Earth. So far, our research is revealing that photosynthesis can occur quite efficiently in environments that are very different from our planet.

    ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2

Education & Public Outreach

Publications

  • Abe, Y., Abe-Ouchi, A., Sleep, N. H., & Zahnle, K. J. (2011). Habitable Zone Limits for Dry Planets. Astrobiology, 11(5), 443–460. doi:10.1089/ast.2010.0545

  • Anderson, R. E., Brazelton, W. J., & Baross, J. A. (2011). Is the Genetic Landscape of the Deep Subsurface Biosphere Affected by Viruses?. Frontiers in Microbiology, 2. doi:10.3389/fmicb.2011.00219

  • Anderson, R. E., Brazelton, W. J., & Baross, J. A. (2011). Using CRISPRs as a metagenomic tool to identify microbial hosts of a diffuse flow hydrothermal vent viral assemblage. FEMS Microbiology Ecology, 77(1), 120–133. doi:10.1111/j.1574-6941.2011.01090.x

  • Barnes, R., Greenberg, R., Quinn, T. R., McArthur, B. E., & Fritz Benedict, G. (2010). ORIGIN AND DYNAMICS OF THE MUTUALLY INCLINED ORBITS OF υ ANDROMEDAE c AND d. The Astrophysical Journal, 726(2), 71. doi:10.1088/0004-637x/726/2/71

  • Beal, E. J., Claire, M. W., & House, C. H. (2011). High rates of anaerobic methanotrophy at low sulfate concentrations with implications for past and present methane levels. Geobiology, None, no–no. doi:10.1111/j.1472-4669.2010.00267.x

  • Bolmont, E., Raymond, S. N., & Leconte, J. (2011). Tidal evolution of planets around brown dwarfs. A&A, 535, A94. doi:10.1051/0004-6361/201117734

  • Brazelton, W. J., Mehta, M. P., Kelley, D. S., & Baross, J. A. (2011). Physiological Differentiation within a Single-Species Biofilm Fueled by Serpentinization. mBio, 2(4), e00127–11–e00127–11. doi:10.1128/mbio.00127-11

  • Brazelton, W. J., Sogin, M. L., & Baross, J. A. (2010). Multiple scales of diversification within natural populations of archaea in hydrothermal chimney biofilms. Environmental Microbiology Reports, 2(2), 236–242. doi:10.1111/j.1758-2229.2009.00097.x

  • Campbell, A. J., Waddington, E. D., & Warren, S. G. (2011). Refugium for surface life on Snowball Earth in a nearly-enclosed sea? A first simple model for sea-glacier invasion. Geophysical Research Letters, 38(19), n/a–n/a. doi:10.1029/2011gl048846

  • Cerritos, R., Eguiarte, L. E., Avitia, M., Siefert, J., Travisano, M., Rodríguez-Verdugo, A., & Souza, V. (2010). Diversity of culturable thermo-resistant aquatic bacteria along an environmental gradient in Cuatro Ciénegas, Coahuila, México. Antonie van Leeuwenhoek, 99(2), 303–318. doi:10.1007/s10482-010-9490-9

  • Cowan, N. B., Robinson, T., Livengood, T. A., Deming, D., Agol, E., A’Hearn, M. F., … Wellnitz, D. D. (2011). ROTATIONAL VARIABILITY OF EARTH’S POLAR REGIONS: IMPLICATIONS FOR DETECTING SNOWBALL PLANETS. The Astrophysical Journal, 731(1), 76. doi:10.1088/0004-637x/731/1/76

  • Crow, C. A., McFadden, L. A., Robinson, T., Meadows, V. S., Livengood, T. A., Hewagama, T., … Wellnitz, D. (2011). VIEWS FROM EPOXI : COLORS IN OUR SOLAR SYSTEM AS AN ANALOG FOR EXTRASOLAR PLANETS. The Astrophysical Journal, 729(2), 130. doi:10.1088/0004-637x/729/2/130

  • Domagal-Goldman, S. D., Meadows, V. S., Claire, M. W., & Kasting, J. F. (2011). Using Biogenic Sulfur Gases as Remotely Detectable Biosignatures on Anoxic Planets. Astrobiology, 11(5), 419–441. doi:10.1089/ast.2010.0509

  • Goldblatt, C., & Zahnle, K. J. (2011). Clouds and the Faint Young Sun Paradox. Clim. Past, 7(1), 203–220. doi:10.5194/cp-7-203-2011

  • Goldblatt, C., & Zahnle, K. J. (2011). Faint young Sun paradox remains. Nature, 474(7349), E1–E1. doi:10.1038/nature09961

  • Goldman, A. D., Baross, J. A., & Samudrala, R. (2012). The Enzymatic and Metabolic Capabilities of Early Life. PLoS ONE, 7(9), e39912. doi:10.1371/journal.pone.0039912

  • Haqq-Misra, J., Kasting, J. F., & Lee, S. (2011). Availability of O 2 and H 2 O 2 on Pre-Photosynthetic Earth. Astrobiology, 11(4), 293–302. doi:10.1089/ast.2010.0572

  • Heller, R., Barnes, R., & Leconte, J. (2011). Habitability of Extrasolar Planets and Tidal Spin Evolution. Orig Life Evol Biosph, 41(6), 539–543. doi:10.1007/s11084-011-9252-3

  • Heller, R., Leconte, J., & Barnes, R. (2011). Tidal obliquity evolution of potentially habitable planets. A&A, 528, A27. doi:10.1051/0004-6361/201015809

  • Jackson, B., Miller, N., Barnes, R., Raymond, S. N., Fortney, J. J., & Greenberg, R. (2010). The roles of tidal evolution and evaporative mass loss in the origin of CoRoT-7 b. Monthly Notices of the Royal Astronomical Society, 407(2), 910–922. doi:10.1111/j.1365-2966.2010.17012.x

  • Kaib, N. A., Quinn, T., & Brasser, R. (2010). DECREASING COMPUTING TIME WITH SYMPLECTIC CORRECTORS IN ADAPTIVE TIMESTEPPING ROUTINES. The Astronomical Journal, 141(1), 3. doi:10.1088/0004-6256/141/1/3

  • Kaib, N. A., Raymond, S. N., & Duncan, M. J. (2011). 55 CANCRI: A COPLANAR PLANETARY SYSTEM THAT IS LIKELY MISALIGNED WITH ITS STAR. The Astrophysical Journal, 742(2), L24. doi:10.1088/2041-8205/742/2/l24

  • Kaib, N. A., Roškar, R., & Quinn, T. (2011). Sedna and the Oort Cloud around a migrating Sun. Icarus, 215(2), 491–507. doi:10.1016/j.icarus.2011.07.037

  • Kaltenegger, L., Segura, A., & Mohanty, S. (2011). MODEL SPECTRA OF THE FIRST POTENTIALLY HABITABLE SUPER-EARTH—Gl581d. The Astrophysical Journal, 733(1), 35. doi:10.1088/0004-637x/733/1/35

  • Kaye, J. Z., Sylvan, J. B., Edwards, K. J., & Baross, J. A. (2010). Halomonas and Marinobacter ecotypes from hydrothermal vent, subseafloor and deep-sea environments. FEMS Microbiology Ecology, 75(1), 123–133. doi:10.1111/j.1574-6941.2010.00984.x

  • Kundurthy, P., Agol, E., Becker, A. C., Barnes, R., Williams, B., & Mukadam, A. (2011). APOSTLE OBSERVATIONS OF GJ 1214b: SYSTEM PARAMETERS AND EVIDENCE FOR STELLAR ACTIVITY. The Astrophysical Journal, 731(2), 123. doi:10.1088/0004-637x/731/2/123

  • Lee, B. L., Ge, J., Fleming, S. W., Stassun, K. G., Gaudi, B. S., Barnes, R., … Xie, J-W. (2011). MARVELS-1b: A SHORT-PERIOD, BROWN DWARF DESERT CANDIDATE FROM THE SDSS-III MARVELS PLANET SEARCH. The Astrophysical Journal, 728(1), 32. doi:10.1088/0004-637x/728/1/32

  • Léger, A., Grasset, O., Fegley, B., Codron, F., Albarede, A. F., Barge, P., … Sotin, C. (2011). The extreme physical properties of the CoRoT-7b super-Earth. Icarus, 213(1), 1–11. doi:10.1016/j.icarus.2011.02.004

  • Marley, M. S., Saumon, D., & Goldblatt, C. (2010). A PATCHY CLOUD MODEL FOR THE L TO T DWARF TRANSITION. The Astrophysical Journal, 723(1), L117–L121. doi:10.1088/2041-8205/723/1/l117

  • Mielke, S. P., Kiang, N. Y., Blankenship, R. E., Gunner, M. R., & Mauzerall, D. (2011). Efficiency of photosynthesis in a Chl d-utilizing cyanobacterium is comparable to or higher than that in Chl a-utilizing oxygenic species. Biochimica et Biophysica Acta (BBA) – Bioenergetics, 1807(9), 1231–1236. doi:10.1016/j.bbabio.2011.06.007

  • Morbidelli, A., Lunine, J. I., O’Brien, D. P., Raymond, S. N., & Walsh, K. J. (2012). Building Terrestrial Planets. Annual Review of Earth and Planetary Sciences, 40(1), 251–275. doi:10.1146/annurev-earth-042711-105319

  • Pan, L., Padoan, P., Scalo, J., Kritsuk, A. G., & Norman, M. L. (2011). TURBULENT CLUSTERING OF PROTOPLANETARY DUST AND PLANETESIMAL FORMATION. The Astrophysical Journal, 740(1), 6. doi:10.1088/0004-637x/740/1/6

  • Pan, L., Scannapieco, E., & Scalo, J. (2012). The pollution of pristine material in compressible turbulence. Journal of Fluid Mechanics, 700, 459–489. doi:10.1017/jfm.2012.143

  • Pierens, A., & Raymond, S. N. (2011). Two phase, inward-then-outward migration of Jupiter and Saturn in the gaseous solar nebula. A&A, 533, A131. doi:10.1051/0004-6361/201117451

  • Raymond, S. N., Armitage, P. J., & Gorelick, N. (2010). PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS. The Astrophysical Journal, 711(2), 772–795. doi:10.1088/0004-637x/711/2/772

  • Raymond, S. N., Armitage, P. J., Moro-Martín, A., Booth, M., Wyatt, M. C., Armstrong, J. C., … West, A. A. (2011). Debris disks as signposts of terrestrial planet formation. A&A, 530, A62. doi:10.1051/0004-6361/201116456

  • Raymond, S. N., Armitage, P. J., Moro-Martín, A., Booth, M., Wyatt, M. C., Armstrong, J. C., … West, A. A. (2012). Debris disks as signposts of terrestrial planet formation. A&A, 541, A11. doi:10.1051/0004-6361/201117049

  • Roberson, A. L., Roadt, J., Halevy, I., & Kasting, J. F. (2011). Greenhouse warming by nitrous oxide and methane in the Proterozoic Eon. Geobiology, 9(4), 313–320. doi:10.1111/j.1472-4669.2011.00286.x

  • Robinson, T. D. (2011). MODELING THE INFRARED SPECTRUM OF THE EARTH-MOON SYSTEM: IMPLICATIONS FOR THE DETECTION AND CHARACTERIZATION OF EARTHLIKE EXTRASOLAR PLANETS AND THEIR MOONLIKE COMPANIONS. The Astrophysical Journal, 741(1), 51. doi:10.1088/0004-637x/741/1/51

  • Robinson, T. D., Meadows, V. S., & Crisp, D. (2010). DETECTING OCEANS ON EXTRASOLAR PLANETS USING THE GLINT EFFECT. The Astrophysical Journal, 721(1), L67–L71. doi:10.1088/2041-8205/721/1/l67

  • Robinson, T. D., Meadows, V. S., Crisp, D., Deming, D., A’Hearn, M. F., Charbonneau, D., … Wellnitz, D. D. (2011). Earth as an Extrasolar Planet: Earth Model Validation Using EPOXI Earth Observations. Astrobiology, 11(5), 393–408. doi:10.1089/ast.2011.0642

  • Rothman, L. S., Gordon, I. E., Barber, R. J., Dothe, H., Gamache, R. R., Goldman, A., … Tennyson, J. (2010). HITEMP, the high-temperature molecular spectroscopic database. Journal of Quantitative Spectroscopy and Radiative Transfer, 111(15), 2139–2150. doi:10.1016/j.jqsrt.2010.05.001

  • Sleep, N. H. (2011). Seismically observable features of mature stagnant-lid convection at the base of the lithosphere: Some scaling relationships. Geochem. Geophys. Geosyst., 12(10), n/a–n/a. doi:10.1029/2011gc003760

  • Sleep, N. H. (2011). Small-scale convection beneath oceans and continents. Chin. Sci. Bull., 56(13), 1292–1317. doi:10.1007/s11434-011-4435-x

  • Sleep, N. H., Bird, D. K., & Pope, E. C. (2011). Serpentinite and the dawn of life. Philosophical Transactions of the Royal Society B: Biological Sciences, 366(1580), 2857–2869. doi:10.1098/rstb.2011.0129

  • Summons, R. E., Amend, J. P., Bish, D., Buick, R., Cody, G. D., Des Marais, D. J., … Sumner, D. Y. (2011). Preservation of Martian Organic and Environmental Records: Final Report of the Mars Biosignature Working Group. Astrobiology, 11(2), 157–181. doi:10.1089/ast.2010.0506

  • Tennyson, J., Bernath, P. F., Brown, L. R., Campargue, A., Császár, A. G., Daumont, L., … Voronin, B. A. (2010). IUPAC critical evaluation of the rotational–vibrational spectra of water vapor. Part II. Journal of Quantitative Spectroscopy and Radiative Transfer, 111(15), 2160–2184. doi:10.1016/j.jqsrt.2010.06.012

  • Tian, F., Kasting, J. F., & Zahnle, K. (2011). Revisiting HCN formation in Earth’s early atmosphere. Earth and Planetary Science Letters, 308(3-4), 417–423. doi:10.1016/j.epsl.2011.06.011

  • Tinetti, G., Deroo, P., Swain, M. R., Griffith, C. A., Vasisht, G., Brown, L. R., … McCullough, P. (2010). PROBING THE TERMINATOR REGION ATMOSPHERE OF THE HOT-JUPITER XO-1b WITH TRANSMISSION SPECTROSCOPY. The Astrophysical Journal, 712(2), L139–L142. doi:10.1088/2041-8205/712/2/l139

  • Tinetti, G., Griffith, C. A., Swain, M. R., Deroo, P., Beaulieu, J. P., Vasisht, G., … Brown, L. R. (2010). Exploring extrasolar worlds: from gas giants to terrestrial habitable planets. Faraday Discussions, 147, 369. doi:10.1039/c005126h

  • Vance, S., Christensen, L. E., Webster, C. R., & Sung, K. (2011). Volatile organic sulfur compounds as biomarkers complementary to methane: Infrared absorption spectroscopy of CH3SH enables insitu measurements on Earth and Mars. Planetary and Space Science, 59(2-3), 299–303. doi:10.1016/j.pss.2010.08.023

  • Walkowicz, L. M., Basri, G., Batalha, N., Gilliland, R. L., Jenkins, J., Borucki, W. J., … Bryson, S. (2011). WHITE-LIGHT FLARES ON COOL STARS IN THE KEPLER QUARTER 1 DATA. The Astronomical Journal, 141(2), 50. doi:10.1088/0004-6256/141/2/50

  • Walsh, K. J., Morbidelli, A., Raymond, S. N., O’Brien, D. P., & Mandell, A. M. (2011). A low mass for Mars from Jupiter’s early gas-driven migration. Nature, 475(7355), 206–209. doi:10.1038/nature10201

  • Walter, M., Baross, J., Coustenis, A., Horner, J., Kress, M., Meech, K., … Woolf, N. (2011). Message from the Executive Council of the Astrobiology Society: The First Year. Astrobiology, 11(1), 75–75. doi:10.1089/ast.2011.1050

  • Zahnle, K., Freedman, R. S., & Catling, D. C. (2011). Is there methane on Mars?. Icarus, 212(2), 493–503. doi:10.1016/j.icarus.2010.11.027

  • Zerkle, A. L., Claire, M. W., Domagal-Goldman, S. D., Farquhar, J., & Poulton, S. W. (2012). A bistable organic-rich atmosphere on the Neoarchaean Earth. Nature Geosci, 5(5), 359–363. doi:10.1038/ngeo1425

  • Zugger, M. E., Kasting, J. F., Williams, D. M., Kane, T. J., & Philbrick, C. R. (2010). LIGHT SCATTERING FROM EXOPLANET OCEANS AND ATMOSPHERES. The Astrophysical Journal, 723(2), 1168–1179. doi:10.1088/0004-637x/723/2/1168

  • Zugger, M. E., Kasting, J. F., Williams, D. M., Kane, T. J., & Philbrick, C. R. (2011). SEARCHING FOR WATER EARTHS IN THE NEAR-INFRARED. The Astrophysical Journal, 739(1), 12. doi:10.1088/0004-637x/739/1/12

  • Zugger, M. E., Kasting, J. F., Williams, D. M., Kane, T. J., & Russell Philbrick, C. (2011). ERRATUM: “LIGHT SCATTERING FROM EXOPLANET OCEANS AND ATMOSPHERES” (2010, ApJ, 723, 1168). The Astrophysical Journal, 739(1), 55. doi:10.1088/0004-637x/739/1/55

  • Aleinov, I., Kiang, N.Y., Romanou, A., Puma, M.J., Kharecha, P., Moorcroft, P.R. & Kim, Y.  (2008).  Global Carbon Cycle Inside GISS ModelE GCM: Results of Equilibrium and Transient Simulations.  AGU Fall Meeting Abstracts, 41: 0019.
  • Amaral-Zettler, L., Artigas, L.F., Baross, J., Bharathi P.A, L., Boetius, A., Chandramohan, D., Herndl, G., Kogure, K., Neal, P., Pedrós-Alió, C., Ramette, A., Schouten, S., Stal, L., Thessen, A., Leeuw, J.d. & Sogin, M.  (2010).  A Global Census of Marine Microbes [Book Chapter].  Life in the World’s Oceans.  Wiley-Blackwell.
  • Armstrong, J., Barnes, R. & Domagal-Goldman, S.  (2010).  Obliquity variations in stable, high-inclination planetary systems and the impact on the habitable zone.  APS Four Corners Section Meeting Abstracts, 4CF: 1001.
  • Barnes, R.  (2010).  The Hunt for Habitable Exoplanets.  APS Northwest Section Meeting Abstracts.
  • Barnes, R., Greenberg, R., Quinn, T.R., McArthur, B., Antonsen, A. & Benedict, G.F.  (2011).  Origin, Dynamics and Stability of the Mutually Inclined Orbits of the υ Andromedae Planetary System.  Bulletin of the American Astronomical Society.
  • Barnes, R., Heller, R., Jackson, B., Leconte, J., Greenberg, R., Mullins, K. & Raymond, S.N.  (2011).  The Role of Tides in Planetary Habitability.  Bulletin of the American Astronomical Society.
  • Barnes, R., Jackson, B., Greenberg, R., Raymond, S.N., Heller, R., Gelino, D.M. & Ribas, I.  (2010).  Tidal Constraints on Planetary Habitability.  Pathways Towards Habitable Planets.
  • Barnes, R., Meadows, V.S., Domagal-Goldman, S.D., Heller, R., Jackson, B., Lopez-Morales, M., Tanner, A., Gomez-Perez, N. & Ruedas, T.  (2010).  Habitability of Planets Orbiting Cool Stars [Online].  Website: http://adsabs.harvard.edu/abs/2010arXiv1012.1883B.
  • Brown, L.R.  (2010).  Spectroscopic Databases for Astronomical Applications (invited %speaker).  Proceedings for the NASA Laboratory Astrophysics Workshop.
  • Brown, L.R., Chen, P., Drouin, B.J., Miller, C.E., Pearson, J., Sander, S.P., Sung, K., Toth, R.A. & Yu, S.  White paper for the Planetary Decadal Survey: Laboratory Spectroscopy to Support Remote Sensing of Atmospheric Composition.  Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109.
  • Carter, R.T., Jandir, P.S. & Kress, M.E.  (2010).  Constraining the Drag Coefficients of Meteors in Dark Flight.  Meteoroids 2010 Conference.
  • Catling, D.C., Leovy, C.B., Wood, S.E. & Day, M.D.  (2011).  A Lava Sea in the Northern Plains of Mars: Circumpolar Hesperian Oceans Reconsidered.  Lunar and Planetary Institute Science Conference Abstracts.
  • Claire, M. & Kasting, J.F.  (2010).  Variations in the magnitude of non mass dependent sulfur fractionation in the Archean atmosphere.  AGU Fall Meeting Abstracts, 14: 03.
  • Claire, M., Sheets, J., Cohen, M., Ribas, I. & Catling, D.  (2011).  The Evolution Of The Solar Flux: Quantitative Estimates For Planetary Studies.  Bulletin of the American Astronomical Society.
  • Conrad, P.G. & Eigenbrode, J.L.  (2011).  Upheaval Dome: An Analogue Site for Gale Crater.  Analogues Workshop, 42nd Lunar and Planetary Science Conference.
  • Conrad, P.G., Eigenbrode, J.L., Mahaffy, P.M. & Steele, A.  (2011).  Environmental Signatures for Habitability: What to Measure and How to Rank the Habitability Potential of Mars.  ESA/NASA Exploring Mars Habitability.  Lisbon, Portugal.
  • Crow, C., McFadden, L.A., Robinson, T., Meadows, V., Livengood, T.A., Hewagama, T., Barry, R.K., Deming, L.D. & Lisse, C.M.  (2010).  Views from EPOXI: Colors in our Solar System as an Analog for Extrasolar Planets.  Bulletin of the American Astronomical Society.
  • Domagal-Goldman, S., Barnes, R., Armstrong, J.C., Breiner, J. & Meadows, V.S.  (2011).  Tilt-a-Worlds: Effects of High Rates of Obliquity Change on the Habitability of Extrasolar Planets.  Bulletin of the American Astronomical Society.
  • Dong, M., Mielke, S.P. & Gunner, M.R.  (In Preparation).  Comparison of A. marina and T. elongatus PSII reaction centers.
  • Evans, N., Meadows, V.S. & Domagal-Goldman, S.D.  (2011).  Exploring The Detectability of Terrestrial Exoplanet Characteristics.  Bulletin of the American Astronomical Society.
  • Halevy, I., Johnston, D.T. & Schrag, D.P.  (2010).  Constraints on the Archean Surface Environment from Mass-Independent Sulfur Isotopes (Invited).  AGU Fall Meeting Abstracts, 14: 02.
  • Ivezic, Z., Juric, M., Lupton, R.H., Tabachnik, S. & Quinn, T.  (2010).  SDSS Moving Object Catalog V3.0.
  • Jackson, B., Penev, K. & Barnes, R.  (2011).  Constraining Tidal Dissipation in Stars and Destruction Rates of Exoplanets.  Bulletin of the American Astronomical Society.
  • Kaib, N.A., Roskar, R. & Quinn, T.  (2011).  Sedna As A Footprint Of The Sun’s Migration Within The Milky Way.  Bulletin of the American Astronomical Society.
  • Kaib, N.A., Roskar, R. & Quinn, T.  (2011).  Sedna and the Evolving Solar Neighborhood.  Bulletin of the American Astronomical Society.
  • Kopparapu, R.K. & Barnes, R.  (2011).  Dynamical Stability of Earth-mass Planets in the Presence of Two Giant Planets.  Bulletin of the American Astronomical Society.
  • Kopparapu, R.K., Kasting, J.F. & Zahnle, K.J.  (In Preparation).  Habitable Zones Around Low Mass Stars.
  • Kress, M.E., Belle, C.L., Cody, G.D., Pevyhouse, A.R., Iraci, L.T. & Brownlee, D.E.  (2010).  Astmospheric Chemistry of Micrometeoritic Organic Compounds.  Meteoroids 2010 Conference.
  • Kundurthy, P., Agol, E., Becker, A.C., Barnes, R. & Williams, B.  (2011).  APOSTLE Observations of GJ 1214b: Constraints on System Parameters and Evidence for Stellar Activity.  Bulletin of the American Astronomical Society.
  • Meadows, V.  (2011).  Detecting Planetary Habitability.  Bulletin of the American Astronomical Society.
  • Mielke, S.P. & et al.  (2010).  Constraining photosynthetic biosignatures: spectral photoacoustic measurements of photon energy use efficiency in the far-red/near-infrared by the chlorophyll d-utilizing cyanobacterium Acaryochloris marina.  15th International Congress on Photosynthesis.  Beijing, China.
  • Mielke, S.P., Kiang, N.Y., Blankenship, R.E. & Mauzerall, D.  (In Preparation).  Wavelength-dependence of the in vivo energy-storage efficiency in the cyanobacterium, Acaryochloris marina.
  • Mielke, S.P., Kiang, N.Y., Blankenship, R.E., Gunner, M.R. & Mauzerall, D.  (2010).  Photosynthetic Electron-Transfer in the Cyanobacterium, Acaryochloris Marina.  LPI Contributions, 1538: 5438.
  • Pevyhouse, A.R. & Kress, M.E.  (2010).  Modeling the Entry of Micrometeoroids in the Atmospheres of Earth-like Planets.  Meteoroids 2010 Conference.
  • Ramirez, R., Kopparapu, R., Freedman, R. & Kasting, J.F.  (2011, Submitted for Review).  Greenhouse warming by dense CO2/CH4 atmospheres and a critique of the impact hypothesis for martian valley formation.  Icarus.
  • Robinson, T.D., Meadows, V. & Crisp, D.  (2010).  Earth as an Extrasolar Planet.  Bulletin of the American Astronomical Society.
  • Shields, A., Meadows, V.S., Robinson, T.D., Crisp, D., Deming, D., A’Hearn, M.F., Charbonneau, D., Livengood, T.A., Seager, S., Barry, R.K., Hearty, T., Hewagama, T., Lisse, C.M., McFadden, L., Wellnitz, D.D. & Team, E.E.  (2011).  Earth as an Extrasolar Planet: Comparing Polar and Equatorial Views of Modern Day and Snowball Earth.  Bulletin of the American Astronomical Society.
  • Smith, M., Catling, D.C., Claire, M.W. & Zahnle, K.  (2011).  The photochemistry of early Mars: Implications for sedimentary minerals and life.  Conference on Exploring Mars Habitability.  Lisbon, Portugal.
  • Stueeken, E.E., Anderson, R.E., Bowman, J.S., Brazelton, W.J., Colangelo-Lillis, J., Goldman, A.D., Som, S.M. & Baross, J.A.  (In Preparation).  The Hadean Earth as a global chemical reactor for the origin of life.
  • Sánchez-Flores, M. & Segura, A.  (2011).  Atmospheric chemistry in a habitable planet with a rich CO_2 atmosphere under the effect of a stellar flare.  Revista Mexicana de Astronomia y Astrofisica Conference Series.
  • Templeton, M. & Kress, M.E.  (2010).  A Numerical Study of Micrometeoroids Entering Titan’s Atmosphere.  Meteoroids 2010 Conference.
  • Tian, F.  (2010).  Planetary Atmosphere Stability in the Habitable Zones of M-stars.  AGU Fall Meeting Abstracts, 11: 1336.
  • Tian, F.  (2010).  Planetary Atmosphere Stability in the Habitable Zones of M-stars.  Bulletin of the American Astronomical Society.
  • Tian, F.  (2011).  The Nitrogen Constraint on the Habitability of Planets around Low Mass M-stars.  Extreme Solar System II.  Jackson Hole, WY.
  • Timpe, M.L., Kopparapu, R., Barnes, R., Raymond, S.N., Greenberg, R. & Gorelick, N.  (2011).  Secular Behavior of Exoplanetary Systems: Self-Consistency and Comparisons With The Planet-Planet Scattering Hypothesis.  Bulletin of the American Astronomical Society.
  • Walkowicz, L.M.  (2011).  Cool Stellar Science with LSST.  Bulletin of the American Astronomical Society.
  • Wolf, E.T. & Toon, O.B.  (2010).  a Fractal Aggregate Model of Early Earth Organic Hazes: UV Shielding with Minimal Antigreenhouse Cooling.  AGU Fall Meeting Abstracts, 11: 1317.
  • Zahnle, K., Freedman, R. & Catling, D.  (2011).  Is There Methane on Mars? Part II.  Lunar and Planetary Institute Science Conference Abstracts.
  • Zugger, M., Kasting, J.F., Williams, D.M., Kane, T.J. & Philbrick, C.R.  (2011).  Light Scattering from Exoplanet Oceans and Atmospheres.  Bulletin of the American Astronomical Society.

2011 Teams