"Greeks Bearing Gifts: Determination of the Surface Composition of Trojan Asteriods from NIR Spectroscopy and Spectral Modeling"
Dr. Joshua Emery
The goal of this task is to investigate the surface compositions of Trojan asteroids, to be accomplished by spectral mixing modeling of a rich set of as-yet unpublished near-infrared (NIR) reflective data as well as through collecting and modeling new spectral data over the wavelength range 0.8–4.0 µm using ground-based observatories. The new observations will focus mainly on smaller Trojans than have previously bee studied. Smaller objects are statistically more likely to have undergone recent collisions, and therefore are expected to have “fresh’ surfaces that reveal bulk (primordial) composition. We expect to observe 50 new Trojans, tripling the current dataset. Modeling these and the unpublished data will increase the number of Trojan asteroids that are quantitatively modeled by a factor of 5 or more. NNG05GG880G
"Investigation of Suitable Targets for Space Missions to Near-Earth Objects"
Dr. Joshua Emery
The Near-Earth Objects (NEOs) are small bodies of the Solar System which periodically approach or intersect the Earth's orbit. The NEO population is supposed to be continuously replenished by asteroids and comets and is believed to be one of the principal sources of meteorites found on the Earth. As a consequence, the study of the physical properties of NEOs is interesting for scientic goals, to investigate the nature of the whole population of small bodies of the Solar System. It also provides essential information for technological purposes, considering the potential hazard that these objects constitute to our planet and the development of suitable mitigation strategies both on Earth and from space. In the last years, scientic and technological goals have pushed space agencies to plan and launch space missions to NEOs. In this respect, observations investigating the physical and thermal structure of NEOs are needed in support of future space missions. Due to the wide variety of the orbital characteristics of NEOs, target selection must be able to guarantee both technical feasibility and high scientic return. We therefore propose to carry out spectroscopic observations, in the mid- and far-infrared wavelength range, of NEOs characterized by a high degree of accessibility for a space mission. We have selected 13 targets accessible from Earth for space missions that amount to a total of 24.5 hours of IRS observations to obtain spectroscopic data between 5.2 and 38 microns. The aim of these observations is the investigation of the surface composition and thermal structure and the determination of the albedo and diameter of each selected target.
"IRS Spectroscopy of M-Class Asteroids and 375 Ursula"
Dr. Joshua Emery
We will conduct IRS 5.2--38 micron observations of the emission spectra of 27 M asteroids. Although the visible and near-IR spectra of these asteroids are nearly featureless, ten of these asteroids are now known to have hydration features at 3 micron (Rivkin et al., 2000) that are absent in the spectra of 15 others. We believe that high S/N spectroscopy of these asteroids in the mid-infrared is likely to reveal key compositional information not available in the near-infrared. In particular, it has the potential to resolve the question of whether the M-asteroid population is composed primarily of silicates, or metals, or both. This compositional information in turn is likely to lead to a better understanding of how widespread igneous differentiation was among the parent bodies of the current asteroid population.
"Surface Composition of KBOs, Centaurs, and Low Albedo Asteroids"
Dr. Joshua Emery
We indend to measure broadband fluxes of a sample of Kuiper Belt Objects (KBOs), Centaurs, and low albedo asteroids with IRAC. Ground-based spectra have been recorded from the visible to 2.5 microns for all objects in the target list, but spectral models admit a range of possible compositions. Reflectance in two or, in some cases, three bands (3.6, 4.5, and 5.8 microns) will allow discrimination between possible spectral models, thereby constraining surface compositions. For several objects, thermal emission will be detected in the 8.0-micron band. The simultaneous measurement with IRAC of both reflected and emitted flux will permit estimation of size and albedo for these objects. Compositions of these primitive bodies allow analysis of conditions in the outer solar nebula during formation, diversity in the Kuiper Belt, and possible dynamical and evolutionary links between KBOs, Centaurs, and low albedo asteroids.
"Formation and Evolution of Giant Planet Satellite Systems"
Dr. Paul Estrada
The main objective of this research is the continued advancement in our understanding of the formation and evolution of giant planet satellite systems. Our research is directly applicable to satellite systems that will almost certainly be found around the growing reservoir of observed extrasolar giant planets (EGPs) using forthcoming missions such as COROT (ESA, 2005), Kepler (NASA, 2007), and Eddington (ESA, 2008).
Previously, we have developed a consistent model for the regular satellites of Jupiter, Saturn and Uranus (Mosqueira and Estrada, 2003a,b; hereafter MEab). Which includes satellitesimal migration due to gas drag and tidal torques, and forms satellites by a combination of Safronov-style binary accretion and drift-augmented accretion in an extended, two-component planetary subnebula. The inner disk is set by the location of the centrifugal radius, while the outer disk extends to the location of the irregulars. The transition occurs at the location of the centrifugal radius r c ~ R H/48 (R H = a P (M P/3M *)1/3, where a P and M P are the planet semi-major axis and mass, and M * the mass of the central star), which results from equating the centrifugal and gravitational forces on a parcel of gas whose specific angular momentum is conserved as it enters the planet's Hill sphere (MEa). MEb explicitly address the survival of regular satellites in a minimum mass subnebula enhanced in solids by a factor of ~ 10, which leads to a gas surface density ~ 10 4 g cm -2. In particular, the formation time for Ganymede and Titan (set by the gas drag timescale of satellitesimals) is comparable to their Type I migration time provided one allows for a factor ~ 10 slower migration due to 3-D effects. This surface density is consistent with that obtained using the inviscid gap-opening formula of Rafikov (2002) in a disk with aspect ratio ~ 0.1, which corresponds to a temperature of ~ 250 K and ~ 100 K at Ganymede and Titan, respectively. This can work provided turbulence subsides and Type II migration ceases. We have also developed an alternative model for formation of satellites around gas giant planets under the assumption that an unknown mechanism (e.g., gas turbulence) removes the gas disk in timescale shorter than that for satellite formation (insuring satellite survival). This model thus entails the formation of satellites in a gas-poor environment (of unspecified surface gas density, though the presence of some gas may help to explain the observations). In this model (Estrada and Mosqueira 2005; hereafter EM), which follows along the lines of the work of Safronov (1969; et al. 1986), sun-orbiting planetesimals collide within the planet's Hill sphere and generate a disk primarily of solid material from which the satellites will form. Unlike the previous model, all of the satellites form in a timescale determined by the timescale for planetesimal feeding (> 105 years).
We have investigated the final masses of giant planets in disks with one or more than one giant planet cores (Estrada and Mosqueira 2004; Mosqueira and Estrada 2004). In the core accretion model of giant planet formation (Pollack et al. 1996), when the core reaches critical mass, hydrostatic equilibrium is no longer possible and gas accretion ensues (Mizuno 1980). If the envelope is radiative, the critical core mass is nearly independent of the boundary conditions and is roughly ~ 10 ME (with weak dependence on the rate of planetesimal accretion and the disk opacity; Stevenson 1982). Given that such a core may form at the present location of Jupiter in a time comparable to its Type I migration time (105-106 years; Bate et al. 2003) provided that the nebula was significantly enhanced in solids with respect to the minimum mass solar nebula (Inaba et al. 2003) and stall at this location in a weakly turbulent (α < 10-4) disk (Rafikov 2002), it may be appropriate to assume that such objects inevitably form and drive the evolution of late-phase T Tauri star disks. In this proposal we pursue several projects (7) based on our previous work that relate to each other in a logical and systematic fashion. The main objective is the continued development of a framework for the formation and evolution of giant planet/satellite systems that can be applicable to extrasolar planetary/satellite systems. In particular, a goal of this work is to help to provide constraints on observations of extrasolar planet/satellite systems that will almost certainly be detected in the coming years with upcoming missions such as COROT. Section 2.1 involves a study of the concomitant growth and migration of giant planets. A detailed study will allow us to characterize the diversity of planetary systems, which can be directly compared with statistics of the growing catalogue of EGPs. EGPs, like the gas giants of our own solar system, likely will possess moon systems. Coupled migration of satellites within the circumplanetary gas disk due to the gas tidal torque along with migration of the giant planet can lead to a variety of outcomes that may be constrained using the model of MEab. This task is outlined in sec. 2.2. Our goal is to characterize the diversity of these satellite systems in order to provide potentially valuable constraints on the detectability of these moons in time for upcoming missions designed to detect EGP moons. In sec. 2.3, we study the consequences of increasing solar luminosity on Ganymedean and super-Ganymedean moons in orbit around migrating giant planets. In sec. 2.4, we continue development of our recently submitted gas-poor planetesimal capture model for the formation of satellites around gas giant planets (EM). In sec 2.5, we describe a scenario for the impact origin of Titan's eccentricity that could potentially explain the inner icy saturnian satellites as well as provide an explanation for Iapetus consistent with the model of EM. In sec. 2.6, we study the compositions of satellites and in the in-situ formation of Iapetus in the context of the model of MEab. Finally, in sec. 2.7, we describe our development of a dust-coagulation/thermal evolution code that we shall use to model the thermal environment of the circumplanetary disk. NNA05CS95A
"Molecular Spectroscopy, Modeling of Brown Dwarfs and Extra Solar Giant Planets"
Dr. Richard Freedman
The field of brown dwarfs and extra solar giant planets is continuing to produce new and exciting research results. The number of known extra solar giant planets continues to grow with time and new discoveries, including a recent first detection by the Spitzer Infra Red Telescope (SIRTF) of light from an extra solar giant planet. In order to make progress in understanding these objects it is necessary to construct detailed models of these objects so that their physical properties can be better understood. Dr. Freedman’s own work is related to the calculation of atomic and molecular opacities for these objects.
Using both laboratory data and theoretical calculations, the PI is developing and maintaining large molecular databases for use in the opacity calculations that are essential for the modeling of the atmospheres of these objects. He then use the results of these calculations as input to various programs that compute line by line opacities for use in the models. These opacity databases have been greatly extended as compared to the usual room temperature laboratory measurements. This is necessary as the room temperature databases have totally inadequate coverage for higher temperatures when excited levels far above the ground state become populated. The PI has used both laboratory and theoretical predictions to extend these databases, and his past experience in both laboratory and theoretical work allows him to apply the appropriate techniques to generate and prepare the data for use in his opacity programs. NNA05CS86A
"Research in Molecular Spectroscopy and the Atomic and Molecular Opacity of Brown Dwarfs and Extra Solar Giant Planets"
Dr. Richard Freedman
The study of brown dwarfs, objects whose mass is too low to support hydrogen fusion in their interior, has made great progress in the past few years. As more of these objects have been discovered it has become important to understand their properties. These objects are strong emitters in the infra red region of the spectrum because of their relatively low effective temperatures as they are powered only by the energy from gravitational contraction. This work on the opacity sources of these objects uses data on atomic and molecular absorption to produce predictions of the opacity that are incorporated into atmospheric models by my collaborators. These models can then be used to study their spectra, colors, and overall physical properties.
The continuing discovery and cataloging of extra solar giant planets has been proceeding over the past few years. This work is also directly applicable to this field as the physical conditions that govern the opacity in these objects are very similar to those in brown dwarfs. The PI has also been providing calculations for the modeling of these objects.
I have been involved in the measurement of high resolution laboratory data of various molecular species in order to derive data on their line strengths and broadening coefficients. This data has also been used to investigate the physical properties of these molecules such as dipole moment functions and potentials. NCC 2-1357
"Advanced Data Mining Techniques for the Analysis of Large Space Science and Astrophysical Data Sets"
Dr. Paul Gazis
The proposed research is intended to evaluate the suitability of a several promising data mining techniques for the analysis of extremely large data sets and develop these techniques for use by the general space science community. In the process, the proposed research will address outstanding questions related to the evolution of transient events in the solar wind, the classification of near-IR and thermal emission spectra, and the identification of structure in large-scale cosmological surveys. The results of the surveys we perform to test these techniques should have immediate scientific value in their own right. The tools developed under this proposal should be immediately useful for similar surveys involving different data sets. They should also be applicable to a broad range of problems that involve large-scale surveys of multi-dimensional data or extended time series that would be difficult or impossible to perform using any other means. These tools should have immediate relevance to large-scale surveys associated with the search for extra-terrestrial intelligence. NASA Cooperative Grant NNA05CP71A
“Mars Exploration and Education Outreach”
Dr. Virginia Gulick
This project encompasses three broad tasks. Task I outlines Mars Surveyor Landing Site Selection activities and outreach projects being undertaken by the PI to help support NASA Ames’ Center for Mars Exploration (CMEX), the Mars Data Analysis Program, and the Mars Program office at JPL. Task II is a continuing task funded by NASA’s Cross-Enterprise Technology Development program to develop the algorithms needed for a Geologist’s Field Assistant”. Task III support’s PI Gulick as a science Co-I on the HIRISE instrument team, the high-resolution color camera that will fly on the Mars Reconnaissance Orbiter in 2005. Task IV supports PI’s leadership and coordination of HIRISE EP/O activities. NASA Cooperative Agreement NCC 2–1415
“Science and Technology Support for NASA Discovery Program’s Kepler Mission”
Dr. Jon Jenkins
In December 2001, the Kepler Mission became the 10th spaceprobe selected for flight by NASA’s Discovery Program, and the first such mission set to achieve goals under NASA’s Origins theme. Kepler seeks to determine the prevalence of Earth-sized and larger planets orbiting solar-like stars in the solar neighborhood, and to characterize the stellar properties favoring the development of planetary systems. It achieves this goal through transit photometry by monitoring >100,000 main-sequence stars continuously and simultaneously for at least 4 years, to detect signatures of transiting planets in the flux time series of their host stars. This project seeks to support the development of the Kepler flight and ground segments through a diverse set of research efforts. These include: 1) developing planning and requirements documents for the Science Operations Center (SOC) such as the Algorithm Theoretical Basis Document (ATBD) and the Science Pipeline Processing Scenario; 2) supporting development, implementation, and testing of science analysis modules for the SOC Pipeline; 3) conducting trade studies involving simulation and analysis to enable the Kepler Project to make informed design and development decisions; and 4) supporting observations with the Vulcan Camera as a means of providing test bed data for the SOC Pipeline. NASA Cooperative Agreement NNA04CC63A
“Airborne and Ground-Based Studies of Meteor and Sample-Return-Capsule Entry Radiation”
Dr. Peter M.M. Jenniskens
This cooperative agreement is to support field campaigns, called Hyperseed MAC, to study carbon ablation and shock chemistry in the atmospheric impact of natural meter-sized asteroids, as mimicked by the reentry of the sample return capsules of the GENESIS (Sept. 08, 2004), STARDUST (Jan. 15, 2006), and HAYABUSA (June 2007) missions. These are the first hypervelocity sample return missions since the Apollo era, with Stardust exceeding Apollo entry speeds. Hyperseed will make the SRC reentry into a systems-level field test of the performance of thermal protection materials, and into a controlled experiment to test key processes in the exogenous delivery of prebiotic compounds. The Principal Investigator of this cooperative agreement will alsobe the main logistics coordinator, by arranging for available research aircraft, assembling capable researchers and suitable instruments, and contributing to the measurements and data analysis. Measurements will be made of the shock’s radiative heat flux, the body surface temperature, ablation rate, the yield and nature of ablated carbon compounds, and the nature of products from their interaction with the atmosphere. The measurements will be interpreted by models and laboratory experiments developed for the design of thermal protection materials, which will now be applied to the exogenous delivery of organic matter in meter-sized asteroids.This agreement also includes ongoing NASA-sponsored efforts for instrument development and research into the dynamics of meteoroid streams, study of meteor showers, and spectroscopy of meteors. NASA Cooperative Agreement NNA04CK65A
“SOFIA Upper Deck Science Opportunities Workshop”
Dr. Peter M.M. Jenniskens
In order to investigate the science questions that can be addressed in potential future research experiments on the Upper Deck of the Stratospheric Observatory For Infrared Astronomy (SOFIA), a “SOFIA Upper Deck Science Opportunities Workshop”, was held at NASA Ames Research Center from June 21 to June 23, 2004. The primary product of this workshop will be a white paper with a clear articulation of important science questions that such upper deck experiments would address uniquely. Extended (2–5 page) papers were solicited which were published on-line prior to the meeting to serve as a library to assist in the writing of the white paper, writing tasks for which will be allocated at the workshop.
The scientific organizing committee of the meeting consisted of (in no particular order): Dr. Peter Jenniskens (SETI Institute, Main Organizer), Dr. Hansjuerg Jost (BAER Institute, Deputy Organizer), Prof. Mike Taylor (Utah State University), Dr. Ray Russell (The Aerospace Corporation), Dr. Tim Castellano (NASA Ames Research Center), Dr. Frans Rietmeijer (University of New Mexico at Albuquerque), Prof. Hans Stenbaek-Nielsen (Univ. of Alaska, Fairbanks), and Dr. Leonid Pfister (NASA Ames Research Center). The committee was chosen to represent a wide array of potentially interested research fields, including meteor astronomy, atmospheric sciences (gas sampling in the troposphere-stratosphere interface), infrared astronomy, occultation astronomy, stratospheric dust and interplanetary dust particle collection and analysis, auroral and sprite research, and Earth science research. The workshop was aimed at identifying other such research areas. NASA Cooperative Agreement NNG04GM30G
NESC and ESMD have agreed to jointly fund Ames for the Stardust Airborne Observation Campaign. On 1/15/06, at 3 a.m. MST at night, the Stardust Sample Return Capsule (SRC) will be entering the Earth's atmosphere at 12.8 km/s, the fastest man-made object to traverse our atmosphere, delivering cometary dust samples to the Utah Test and Training Range. Ames will conduct an airborne observation of the entry, aiming spectrographic equipment from a DC-8. These data will be useful for validating aerothermodynamic prediction tools and assessing thermal protection system response of the Ames developed PICA material. Peter Jenniskens of the SETI Institute is the Prinicpal Investigator. An international team of participating researchers will deploy a wide range of cameras and spectrographs, using past experience from their particiaption in airborne meteor shower observating campaigns.
"Biochemical Adaptations that Set the Physical and Chemical Limits for Life"
Dr. Hiromi Kagawa
It is a fundamental goal of astrobiology to elucidate the limits to which life has adapted on Earth in an effort to shed light on the inhabitability of worlds beyond Earth. All organisms are adapted to their environments and since all environments vary with time, all organisms have by necessity evolved biochemical strategies for coping with the changes they encounter within their environments. Our research efforts are focussed on understanding the biochemical adaptations that set the tolerable limits for the inevitable environmental variation with which an organism must cope. In particular, we are interested in understanding the strategies of organisms that appear to be 'pushing the envelop' for life by living in extremely harsh or extremely variable environments. How do organisms living in near boiling sulfuric acid (so-called hyperthermophilic acido-philes) adapt their biomolecules and their biochemical systems to thrive under these conditions?
One adaptation that nearly all organisms have made to stressful conditions is the production of specialized proteins, known as "stress proteins" or "chaperonins." The chaperonins are a class of proteins that are thought to play a role in protein refolding, but our research over the last three years clearly demonstrates that these proteins are also playing a role in membrane stabilization.
The chaperonins in the hyperthermophile Sulfolobus shibatae are among the most abundant proteins, constituting as much as 12% of their total protein. These 60 kDa proteins are isolated from cells as double-ring structures. We have observed that purified chaperonins from S. shibatae form ordered filaments and proposed that these filamentous structures, rather than rings, are functional in vivo. Our previous research using immunofluorescence light microscopy (IFM) and immunogold electron microscopy (IEM) indicate that chaperonins are localized to the membrane. This finding is corroborated by centrifugation experiments, which indicate that as much as 90% of the chaperonin protein co-sediments with the membrane rather than the cytosolic fractions. On the basis of these observations, we hypothesized that the role of chaperonins, or chaperonin filaments, in vivo is to stabilize and help regulate the fluidity of the cytoplasmic membrane under normal and stress conditions.
We propose to further test this hypothesis and to clarify the structure and function of hyperthermophilic HSP60s. Our proposed goals are (1) to elucidate critical structural elements of the proteins that allow them to assume higher-order structures (rings and filaments) and (2) to confirm how the three different protein components of the HSP60s interact to define the functional unit in the living cell. To approach both of these goals we intend to use a genetic approach, i.e., to make mutants and to study them in vitro and in vivo. Our ultimate aim is to understand the role of HSP60/chaperonins in the physiology and molecular biology of hyperthermophiles and other organisms. NCC 2-1338
"Functionalization of Carbon Nanotubes, a form of Carbon in the Interstellar Medium, and Optical Properties of Tholin Produced in a Methane-rich Early Earth Atmosphere"
Dr. Bishun Khare
This project consists of two areas of interest:
Functionalization of Carbon Nanotubes, a form of Carbon in the Interstellar Medium. Among all the elements, carbon is the most important element involved in organic chemistry including prebiotic chemistry leading to the origin of life. Like all the rest of the elements, its origin is also in stars. Carbon based organic matter on Earth is known to exist in millions of different compounds. However, in the combined interstellar medium and circumstellar region, 88 molecules have been discovered as of July 1991. Most of the detection was made by microwave spectroscopy. Now with growing advancement in sensitivity and resolution of the mid and far infrared spectroscopy combined with the observations by orbiting space telescope, such as Hubble and Space Station, we expect to discover many more molecules in the coming decades.
Optical Properties of Tholin Produced in Methane-rich Early Earth Atmosphere. We propose to conduct laboratory simulation of possible early Earth atmospheres composed of nitrogen, carbon dioxide, and methane. Previous work has indicated that as the methane to carbon dioxide ratio increases to near unity, solid organic material - tholin - is produced. The focus of this proposal is to measure the optical constants in the solar and thermal infrared wavelengths of tholin produced for varying ratios of methane to carbon dioxide. It has been proposed that the photochemically produced haze on the early Earth may have contributed to the greenhouse effect by providing a UV shield for ammonia and methane - both potent greenhouse gases. However, the antigreenhouse effect of the haze may offset the greenhouse cooling. To quantitatively assess this important issue requires knowledge of the optical properties of the haze. NCC 2-1358
“Astrobiology-Focused Planetary Science And Exploration Investigations In Terrestrial Analog Environments”
Dr. Pascal Lee
An interdisciplinary scientific research program being carried out to advance astrobiology-focused planetary science and exploration based on field investigations in terrestrial analog environments. The proposed research comprises two modules:
1) The “NASA Haughton-Mars Project” (HMP): Science and Exploration Studies at the Haughton Impact Structure and Surrounding Terrain, Devon Island, High Arctic, Viewed as a Mars Analog Site;
2) “Astrobiology in Settings where Water is Extremely Rare” (ANSWER) Studies: Investigation of Water-Poor Extreme Environments for Life.
Both modules address central questions in astrobiology through the investigation of geologic and hydrologic features, settings, and processes in extreme environments on Earth which may serve as analogs for planetary environments, past or present. In each module, the planned research comprises science and technology components. The proposed research will help to advance our understanding of planetary evolution and the possibilities of life in the universe, and will help to plan the future exploration of planets by both robots and humans. NASA Cooperative Agreement NCC 2–1416
“Astrobiology, Planetary Protection and Life beyond the Planet of Origin”
Dr. Rocco Mancinelli
The focus of this project is on life moving beyond its planet of origin, a question of evolutionary interest and because the human exploration of space is the movement of life from Earth and the movement of possible life to Earth from other planets, especially Mars and Europa. With this project, we propose a focused research plan as a nucleus for an expanded emphasis on this area of interplanetary travel of life as the field of Astrobiology matures. Moving beyond the planet of origin requires a vehicle for transport, the ability to transport, and the ability to colonize, thrive and ultimately evolve in the new environment. The core of this study will be to identify organisms and ecosystems that are likely to withstand the rigors of space, using as a guiding principle the hypothesis that desiccation resistance and natural exposure to high levels of radiation are good predictors of survival of travel from one planet to another. Once this work — collecting candidate organisms from various environments, testing them in the lab and in a space simulator, looking at mechanisms underlying the results of survival and death — has been established, we will expand the research to include a flight component and to bring in workers from related fields to study other aspects of natural transport (natural transport mainly mean via a meteorite while intentional transport involves a sample return mission). Primary to this effort is the identification of mechanisms that permit certain organisms to withstand space radiation, space vacuum, desiccation, time in transit, and the physical rigors of leaving the parent body and landing on a new one. Each of these factors can be associated with a probability of survival— the product of the probabilities then provides an estimate of the overall likelihood of survival. This proposed research will provide new insights into the ability of life to propagate through space. NASA Cooperative Agreement NNA04CC93A
“Planetary Biology, Evolution and Intelligence”
Dr. Rocco Mancinelli
We ask three fundamental questions: (1) How does life begin and evolve; (2) Does life exist elsewhere in the universe? and (3) What is the future of life on Earth and beyond? We conduct a set of coupled research projects in the co-evolution of life and its planetary environment, beginning with fundamental ancient transitions that ultimately made complex life possible on Earth, and conclude with a project that brings together many of these investigations into an examination of the suitability of planets orbiting M stars for either single-celled or more complex life. Results will help the next generation scientific Search for Extraterrestrial Intelligence (SETI) choose the 105 to 106 target stars that it will survey for signs of technical civilizations using the new Allen Telescope Array (ATA) being built by the SETI Institute in partnership with the University of California, Berkeley. This research, sponsored by the NASA Astrobiology Institute, intends to elucidate the co-evolution of life and its planetary environment, typically investigating global-scale processes that have shaped, and been shaped by, both. Throughout, we recognize the importance of pursuing the planetary evolution aspects of this research in the context of comparative planetology: since laboratory experiments are impossible over some of the time and spatial scales relevant to early Earth, we must supplement laboratory data with the insight as we can gain by exploring extraterrestrial environments that may provide partial analogs to the early Earth environment and its processes.
We will be exploring two new investigations into the oxidation of early Earths environment. While the biological aspects of this ‘oxygen transition’ have been recently emphasized, both mechanisms to be explored here (peroxy in rocks and aerosol formation in the atmosphere, building on an analogy to processes now occurring in the atmosphere of Saturns moon Titan) are non-biological. If such mechanisms were to be shown to be quantitatively significant, it would suggest that the oxygen transition on an Earth-like world could take place independently of the invention of any particular metabolic pathways (such as photosynthesis or methanogenesis) that have been proposed as driving this transition. Since Earth’s oxygen transition ultimately set the stage for the oxygen-based metabolism evidently essential for metazoa, understanding this transition is crucial to elucidating both Earth’s evolution and the evolution of complex (including intelligent) life. Our geological investigations are tightly coupled with microbiological experiments to understand the extent to which the proposed mechanism might have led to the evolutionary invention of oxidant protective strategies and even aerobic metabolism. One of the major sinks for oxygen on early Earth would have been reduced iron.At the same time iron could have provided shielding against ultraviolet (UV) light that would have been reaching Earth’s surface in the absence of the ozone shield generated by atmospheric oxygen. Nanophase ferric oxide minerals in solution could provide a sunscreen against UV while allowing the transmission of visible light, in turn making the evolution of at least some photosynthetic organisms possible. We will test this hypothesis through coupled mineralogical and microbiological work in both the lab and the field, and examine its implications not only for Earth but for Mars as well with an emphasis on implications for upcoming spacecraft observations. NASA Cooperative Agreement NNA04CC05A
"Mars Analog Research and Technology Experiment (MARTE)"
Dr. John Marshall
The Mars Analog Research and Technology Experiment (MARTE) team is using the search for life in the subsurface of the Rio Tinto as a learning experience for guiding the development of technology for drilling, sample handling and instrumentation to be used in the eventual search for subsurface life on Mars.
The MARTE project is a collaboration between the Spanish Centro de Astrobiologia (CAB) and NASA. CAB is a member of the NASA Astrobiology Institute. Both NASA and CAB are contributing scientific and engineering expertise and money to the project.
MARTE, a three-year project, has two main objectives:
(1) To search for and characterize subsurface life at the Rio Tinto;
(2) To build and test the drilling, sample handling and instrument technologies that will be needed to search for life on Mars.
In the first phase of the project (during 2003) scientists are using a local commercial drilling company and laboratory analysis of samples to search for life. Samples of rock obtained from the drilling are being analyzed to determine if they are inhabited by microorganisms. This part of the project will be used to help our team design a drilling, sample handling and instrumentation system that will be demonstrated at the Rio Tinto in a later phase of the project. The system will be remotely controlled and data will be analyzed by scientists at NASA in California and CAB in Madrid in a simulation of a Mars mission. Funded by NASA Ames Research Center
"Mineral Identification and Composition Analyzer (MICA)"
Dr. John Marshall
The Mineral Identification and Composition Analyzer (MICA) demonstrates a working brassboard of a miniaturized tool for in situ X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), and optical analyses on unprepared rocks accessed by a rover on Mars. MICA will automatically perform these non-destructive analyses to quickly determine the geological nature of samples, image the crystalline structure and appearance, and measure the elemental content. MICA data will be useful for analysis of regolith and rocks that are encountered during exploration of the Mars surface, and selection of unique and interesting samples for return to Earth.
MICA requires no sample acquisition or preparation, only that the instrument be in contact with the sample. A deep depletion charge coupled device (CCD) detects x-rays that interact with the mineral crystals and scatter throughout the 2-theta diffraction angle range from 20 to 70 degrees, and also measures the energy of x-rays generated from fluorescence of the contained elements.
An optical CCD imager with a white (broad-spectrum) LED light source for illumination of the sample is also included to provide visual information regarding the crystalline structure, color, appearance, and morphology of the analyzed sample. Funded by JPL
"Phoenix Mission - MECA"
Dr. John Marshall
Interpretation of MECA microscopy data from both the optical and atomic force microscopes and integration of these data with information from the other scientific instruments on Phoenix. Includes work related to touch-down interactions of the thrusters with the Martian surface. Funded by the University of Arizona
“Interstellar N-Heterocycles, Large Polycyclic Aromatic Hydrocarbons (PAHs)and PAH Clusters as Potential Boimarkers and Cosmic Biogenic Feedstock”
Dr. Andrew Mattioda
The purpose of this research is to investigate the formation and distribution of Aromatic Nitrogen Heterocyclic molecules (ANHs), large polycyclic aromatic hydrocarbons (LPAHs), LPAH clusters, and nanoparticles in the interstellar environment. We will also trace potential chemical modifications upon their inclusion in interstellar ices and the icy materials of developing planetary systems. The ultimate goal of this project is to determine whether interstellar ANH and other related aromatic structures, which are prevalent in our own biochemistry, might indicate an exogenous origin of life.Since tons of organic molecules come to earth every day from space, and this mass may have been a million times more on the prebiotic Earth, such molecules might have aided in making the Earth habitable, perhaps even jump-starting life. By extension, such a delivery process may be generally applicable to habitability of the planets of other stellar systems, and thus is of fundamental interest to our studies of the origins of life in the universe. This project will focus on measuring the infrared (IR) spectra of ANHs, ANH ions, LPAHs, LPAH clusters and nanoparticles under astrophysically relevant conditions; assess their relative stability under UV irradiation; analyze the UV-mediated photochemistry of these species frozen in H2O-dominated ices to determine the relevance of such chemical processes to the interstellar production of biogenically significant compounds. Since nitrogen-containing heterocycles are so important to our biochemistry, particular emphasis will be placed on ANH compounds. However this project is not limited to solely experimental work. In addition to the proposed work, we are actively pursuing related observational and theoretical projects through collaborations with other scientists at NASA, universities, and non-profits. NASA Cooperative Agreement NNA04CC41A
“Molecules in Meteorites and Ice: Pre-Biotic Compounds and Pseudo-Biomarkers”
Dr. Andrew Mattioda
The purpose of this research is to investigate the formation and distribution of organic molecules in space and assess the extent to which such space chemistry may have contributed to the inventory of organic compounds in carbonaceous chondrites and cometary and asteroidal dust (IDPs). Since tons of organic molecules come to Earth every day from space, and the mass may have been a million times more on the prebiotic Earth, such molecules may have made the Earth habitable. By extension, this exogenous delivery process may be generally applicable to habitability of the planets of other stellar systems, and thus is of fundamental importance to SETI. This program focuses on ice experiments and comparison to meteoritic organics, but is not limited to such work. We also are actively pursuing related observational and theoretical projects through collaborations with other scientists at NASA, universities, and non-profits. NASA Cooperative Agreement NCC 2–1414
"Formation and Dynamics of Planetary Ring/Moon Systems"
Dr. Ignacio Mosqueira
In this research the dynamics of the narrow Uranian rings have been studied, the formation of satellite systems of the giant planets have been investigated, and the likely connections existing between rings and moons concerning ring morphology and composition are being pursued. An investigation of three scenarios for ring particle collisions to alter the uniform precession condition applicable to rings that exhibit apse-alignment, bring the theory into better agreement with observations. AS model was generated for the formation, migration and survival of regular satellites of Jupiter, Saturn and Uranus in extended gaseous nebulae. Applications are noted principally to Callisto, Ganymede, Titan, Hyperion, Iapetus and the inner icy satellites of Saturn, are predictions testable by Cassini have been made. An explanation for the Ganymede-Callisto dichotomy is presented that does not rely on fine-tuning poorly known parameters. The research will improve existing ring models by generalizing the streamline precession term due to particle collisions to cases such that the density gradients in the ring take place over lengthscales comparable to the mean free path of a ring particle, and to include the effects of shepherd satellites in the determination of ring masses. A study will be made of the structure of the outer B ring. The satellite formation model will be extended to Neptune by considering a scenario in which Neptune's primordial satellite system was largely analogous to that of Uranus, so as to determine whether the capture of Triton from heliocentric orbits is consistent with the present semi-major axis, eccentricity and inclination of Nereid. We will explore the connections between our satellite formation model, the resulting properties of the inner moons of the giant planets, and the consequences to their ring systems-in particular, (a) why Jupiter has a less massive ring system than Saturn, and (b), why Saturn's rings have high albedo and appear to be made mostly of water ice, while no spectral evidence for the presence of water ice has been found in the case of the Uranian rings. A study will be made of the thermal histories of Ganymede, Callisto and Titan and we will investigate the predictions that current satellite formation models make for the state of Titan when compared to those of Ganymede and Callisto. This research will also adapt a symplectic code to efficiently handle the bombardment of accreting satellite embryos by heliocentric planetesimals in order to address the issue of why Titan is the only large Saturnian satellite. We are expanding our satellite formation model to include 3-D effects on our tidal torque calculations, and are investigating the disk conditions that led to the primordial capture of Hyperion into a 4:3 resonance with Titan but failed to either to capture or to retain such objects in the case of Ganymede and Callisto. By expanding our knowledge base in several key areas as of 2004, the upcoming Cassini mission makes these exciting and timely areas of research. NCC 2-1398
“The Next Generation Search for Earth-like Worlds”
Dr. Alan Penny
This program of research into extrasolar planets will include using existing ground and space facilities to extend our knowledge of planetary systems as a framework for these future missions, and theoretical work on the astrobiology of Earth-like planets. The following areas will be addressed.
1) Future space transit missions
After the NASA Kepler space mission in 2008, there are a number of options for further space transit missions that will only be accessible through space transit observations.
Amongst these observations will be:
all-sky surveys for planets orbiting nearby stars
large aperture wide-field searches for small terrestrial planets
very large aperture telescopes for transit spectroscopy
Dr. Penny will analyse the results of the new all-sky survey of SMEI and the future large area survey possible with the STEREO mission, further coupled with a study of the limitations of ground all-sky surveys, using data acquired by the VULCAN project.
2) Science of extrasolar planetary systems
A search for giant extrasolar planets will be made, using both ground and space telescopes, in order to understand the distribution of planetary systems. These searches will consist of taking part in the Anglo-Australian Telescope Planet Search program, looking for giant planets with the radial velocity method, and using data from the US Air Force/NASA SMEI mission to do a transit search for planets orbiting the brightest stars in the sky. It is intended to propose and participate in the SIM and TPF/Darwin missions.
3) Evaluation of the astrobiology of extrasolar planet space telescopes
Theoretical aspects of the astrobiology of Earth-like planets which are relevant to extrasolar planet missions will be addressed. These will include studies of possible atmospheres and of the effects of biological activity on such atmospheres. NASA Cooperative Agreement NNG05GA41G
“Dark Slope Streaks on Mars: Formation, Changes and Fading"
Dr. Cynthia Phillips
Dark slope streaks on Mars are associated with particular temperate locations, in regions of low thermal inertia. They begin at a point source, and proceed downslope in either simple wedge-shaped or branching patterns, or in complex braided formations. Two major classes of models have been proposed. The dry models suggest that streaks form through dust movement, while the wet models suggest that water, ice, and/or brine are present to lubricate or stain the surface. New slope streaks have been observed forming during the Mars Global Surveyor mission, on timescales as short as about 100 days. We propose to search the database of MOC images for overlapping image pairs that contain slope streaks, and document changes with an iterative coregistration and ratioing technique. We hope to find various details of how slope streaks form, change, or fade over time that could support one of the two major classes of models. If slope streaks are found to require the presence of liquid water, such features could have major astrobiological significance and be important targets for future missions. NASA Cooperative Agreement NNG05GQ61A
“Chemical and Astrobiological Investigations of Mars and Europa Analogs”
This project covers two areas of interest in how to understand more precisely the surficial characteristics of Mars and Europa:
Europa Ice Analyzer
There is observational evidence, supported by theoretical considerations, for the simultaneous presence of both oxidants and organics in the surface ices of Europa. Chyba (2000) has argued that disequilibrium chemistry in the ice should produce enough organic and oxidant molecules to fuel a substantial biota in the Europan oceans. These oxidants and organics form the observational targets of the proposed instrument. Their in-situ detection and confirmation represent one of the most significant challenges in the next decade of Europa investigations.
Mars Oxidant Instrument
The Mars Oxidant Instrument (MOI) seeks to characterize, quantify, and identify Martian oxidants. MOI is a survey instrument that treats the soil as a composite of unknown reactants that can be modeled and identified by cataloging the reactivity of these species with a set of well-characterized reference materials. The method uses a suite of integrating solid-state chemical sensors that results in a simple, low-mass, low-power analyzer that can operate in a non-aqueous mode. The MOI instrument is derived from a series of instruments and investigations that have aimed at understanding the nature of Martian oxidants. The method of using thin-film reference reactants to probe solid/solid reactions has heritage that extends from the development and production of the Mars Oxidant (MOx) instrument on the ill-fated 1996 Russian Mars mission (Grunthaner et al., 1995; McKay et al., 1998). The Thermo-Acoustic Oxidant Sensor (TAOS) (Zent et al., 1998) extended the capability of MOx through the utilization of chemiresistors, the transducers employed by MOI. NASA Cooperative Agreement NCC 2–1408