2014 Annual Science Report
Astrobiology Roadmap Objective 2.2 Reports Reporting | SEP 2013 – DEC 2014
Roadmap Objective 2.2—Outer Solar System exploration
Project Reports
-
Advancing Techniques for in Situ Analysis of Complex Organics: Laser Mass Spectrometry of Planetary Materials
In this final reporting period under CAN-5, we extended the development of protocols for laser mass spectrometry (MS) for analysis of complex, nonvolatile organic molecules from the progress made last year. In particular the major area of focus was in (1) the use of tunable laser wavelengths for desorption in two-step laser MS (L2MS), and (2) the use of tandem mass spectrometry (MS/MS) for in situ molecular structure analysis. Each of these protocols has been investigated during the course of the CAN-5 project, jointly supported by NAI and instrument development (PIDDP, MatISSE) and flight (MOMA) programs. The unique aspect of these efforts is their implementation and evaluation using truly miniature, flight-like instrumentation, to optimize the benefit to real mission science.
ROADMAP OBJECTIVES: 2.1 2.2 3.2 7.1 -
Astrobiology of Icy Worlds
Our goal in the Astrobiology of the Icy Worlds Investigation is to advance our understanding of the role of ice in the broad context of astrobiology through a combined laboratory, numerical, analytical, and field investigations. Icy Worlds team pursues this goal through four major investigations namely, the habitability, survivability, and detectability of life of icy worlds coupled with “Path to Flight” Technology demonstrations. A search for life linked to the search for water should naturally “follow the ice”. Can life emerge and thrive in a cold, lightless world beneath hundreds of kilometers of ice? And if so, do the icy shells hold clues to life in the subsurface? These questions are the primary motivation of our science investigations
ROADMAP OBJECTIVES: 1.1 2.1 2.2 3.1 3.2 4.1 5.1 5.2 5.3 6.2 7.1 -
Co-Crystals on the Surface of Titan
We have discovered that benzene and ethane form a co-crystalline inclusion compound at Titan surface temperatures and pressures. Co-crystals of other organic compounds could be common on Titan’s surface. These results can help explain the release of ethane observed at the Huygens landing site, and point to a new type of surface material that may have significant impact on Titan surface chemistry and geology.
ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 -
Cosmic Distribution of Chemical Complexity
This project explores the connections between chemistry in space and the origin of life. It is comprised of three tightly interwoven tasks. We track the formation and evolution of chemical complexity in space starting with simple carbon-rich molecules such as formaldehyde and acetylene. We then move on to more complex species including amino acids, nucleic acids and polycyclic aromatic hydrocarbons. The work focuses on carbon-rich species that are interesting from a biogenic perspective and on understanding their possible roles in the origin of life on habitable worlds. We do this by measuring the spectra and chemistry of analog materials in the laboratory, by remote sensing with small spacecraft, and by analysis of extraterrestrial samples returned by spacecraft or that fall to Earth as meteorites. We then use these results to interpret astronomical observations made with ground-based and orbiting telescopes.
ROADMAP OBJECTIVES: 2.2 3.1 3.2 -
Life Underground
Our multi-disciplinary team from USC, Caltech, JPL, DRI, RPI, and now also Northwestern is developing and employing field, laboratory, and modeling approaches aimed at detecting and characterizing microbial life in the subsurface—the intraterrestrials. We posit that if life exists, or ever existed, on Mars or other planetary body in our solar system, evidence thereof would most likely be found in the subsurface. This study takes advantage of unique opportunities to explore the subsurface ecosystems on Earth through boreholes, mine shafts, sediment coring, marine vents and seeps, and deeply-sourced springs. Access to the subsurface—both continental and marine—and broad characterization of the rocks, fluids, and microbial inhabitants is central to this study. Our focused research themes require subsurface samples for laboratory and in situ experiments. Specifically, we are carrying out in situ life detection, culturing and isolation of heretofore unknown intraterrestrial archaea and bacteria using numerous novel and traditional techniques, and incorporating new and existing data into regional and global metabolic energy models.
ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.3 4.1 5.1 5.2 5.3 6.1 6.2 7.2 -
Development of Direct Sampling Methodology for Analysis of Complex Organic Mixtures on Titan’s Surface
Photochemistry in Titan’s dense atmosphere generates a complex mixture of organic molecules that have been deposited on Titan’s surface over time. Requiring no sample pretreatment or handling, the technique of direct analysis in real time (DART), combined with an ion trap mass spectrometer having MS/MS capability, is shown to be an enabling experimental methodology to vaporize, ionize, and structurally characterize organic components of this mixture. A key important development is the use of temperature programmed desorption, accomplished by heating of the probe gas, to examine complex mixtures of organics with a wide range of volatility (polypropylene glycol and tar samples from a petroleum seep). Of particular relevance to astrobiology, this methodology is employed to compare Titan simulants produced in a pulsed discharge from gas mixtures designed to probe mechanistic pathways leading to high molecular weight products.
ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 -
Disks and the Origins of Planetary Systems
This task is concerned with the evolution of complex habitable environments. The planet formation process begins with fragmentation of large molecular clouds into flattened disks. This disk is in many ways an astrochemical “primeval soup” in which cosmically abundant elements are assembled into increasingly complex hydrocarbons and mixed in the dust and gas within the disk. Gravitational attraction among the myriad small bodies leads to planet formation. If the newly formed planet is a suitable distance from its star to support liquid water at the surface, it is in the so-called “habitable zone.” The formation process and identification of such life-supporting bodies is the goal of this project.
ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1 4.1 4.3 -
Biosignatures in Extraterrestrial Settings
The Biosignatures in Extraterrestrial Environments group works on finding and characterizing exoplanets, in particular through very high resolution spectroscopy; and developing new techniques for finding exoplanets and characterizing their properties. It also works on understanding the evolution and dynamics of planetary systems, including the solar system, and the role of astrophysical processes in establishing and sustaining life in extraterrestrial environments.
ROADMAP OBJECTIVES: 1.1 1.2 2.1 2.2 3.1 4.1 4.3 6.2 7.1 7.2 -
Longer Wavelength Photochemistry of Condensates and Aerosols in Titan’s Lower Atmosphere and on the Surface
This study focuses on the condensed phase photochemistry on Titan. In particular, we focus on understanding longer wavelength photochemistry of solid hydrocarbons so simulate photochemistry that could occur based on the UV penetration through the atmosphere and on the evolution of complex organic species in astrobiologically significant regions on Titan’s surface. Here we investigate the oxygenation chemistry involving the condensed Titan’s organic aerosols with water-ice on Titan’s surface – induced by high energy photons simulating the cosmic ray induced chemistry on Titan’s surface.
ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3 -
Comets as Keys to Solar System Formation
Comets are both a key indicator of the processes that formed the early Solar System and potentially a source of volatiles and organics needed to make habitable planets. In this work we investigate how modern theories of planet and planetesimal formation may lead to predicted signatures in comets and, when compared with real comets, to tests of those theories.
ROADMAP OBJECTIVES: 1.1 2.2 -
Exoplanet Detection and Characterization: Observations, Techniques and Retrieval
In this task, VPL team members use observations and theory to better understand how to detect and characterize extrasolar planets. Techniques to improve the detection of extrasolar planets, and in particular smaller, potentially Earth-like planets are developed, along with techniques to probe the physical and chemical properties of exoplanet atmospheres. These latter techniques require analysis of spectra to best understand how it might be possible to identify whether an extrasolar planet is able to support life, or already has life on it.
ROADMAP OBJECTIVES: 1.2 2.2 7.2 -
NAI Titan Education and Public Outreach
Planetariums have a long history of experimentation with audio and visuals to create new multimedia experiences. We report on a series of innovative experiences that began in the Gates Planetarium at the Denver Museum of Nature & Science, combining live performances of music and navigation through scientific visualizations. The Life Out There productions featured a story showcasing astrobiology concepts at scales ranging from galactic to molecular, and told using VJ-ing of immersive visualizations and musical performances from the House Band of the Universe. These hour-long shows were broken into four separate themed musical movements, with an improvisatory mix of music, dome visuals, and spoken science narrative which resulted in no two performances being exactly alike. Post-performance dissemination is continuing via a recorded version of the performance available as a DVD and online streaming video. Written evaluations from visitors who were present at the live shows reveal high satisfaction and subsequent interest in astrobiology topics. Life Out There concerts have been used to inaugurate a new evening program to draw in a younger audience demographic to DMNS, and have been taken on the road to other venues in other cities.
We continued the development and public presentation of this live digital planetarium show about Titan and Astrobiology. This live lecture planetarium show, entitled “Life Out There” makes use of the digital imaging capabilities of the dome, through the innovative Uniview software, a “real time” virtual simulation of the known universe based on accurate astronomical databases and modeling. The inclusion of live musicians, who serve to introduce each section of the show, helps to attract an audience beyond those who reliably come to space science events at the planetarium, and help to create a relaxing and evocative atmosphere conducive to wonder and learning. With Uniview, we can utilize the SPICE Kernels that spacecraft teams use to describe mission trajectories, and create virtual versions that can be followed along through the simulation. Using 3-D spacecraft models, the public can follow spacecraft missions shown with breathtaking realism within the immersive display. We have a detailed model of the Cassini spacecraft, and we are using the most recently updated SPICE kernels of Cassini, including the many Titan flybys, to show the public the fantastic journey of Cassini and Huygens in exploring Titan. In addition to the live lecturer, a second operator controls the Uniview software, allowing these flybys to be seen from any perspective deemed instructive and/or entertaining. Various Cassini and Huygens image data sets, including camera data, infrared spectrometer data and radar data, are being texture mapped and rendered on the moon’s surface. The atmosphere is visually peeled away, and various visuals are used together with an original script and musical score, both written by E/PO lead David Grinspoon, to explore themes of Titan and Astrobiology for the public. The visual content was directed by Dr. KaChun Yu, Curator of Space Sciences at DMNS, in collaboration with Dr. Grinspoon.
We developed, tested, evaluated and disseminated a 20-minute stage show for informal science centers to excite and inform visitors about the science and exploration of Titan. The show utilizes a participatory exercise in scientific illustration to engage visitors in the material. Each participant is given a clipboard and pencils, and the facilitator, using a series of Cassini and Huygens images and videos of Titan, leads them through an exercise in which each draws a sketch of a Titan landscape, learning along the way about many aspects of the Titan environment as revealed by modern exploration. The show has now been seen by many thousands of visitors to the Denver Museum of Nature and Science.
During this last year we focused on disseminating the presentation materials and supporting media, and training materials, including a training DVD for presenters for use at other informal science centers.
We continued the development and public presentation of a live digital planetarium show about Titan and Astrobiology. This live lecture planetarium show, entitled “Life Out There” makes use of the digital imaging capabilities of the dome, through the innovative Uniview software, a “real time” virtual simulation of the known universe based on accurate astronomical databases and modeling. The inclusion of live musicians, who serve to introduce each section of the show, helps to attract an audience beyond those who reliably come to space science events at the planetarium, and help to create a relaxing and evocative atmosphere conducive to wonder and learning. With Uniview, we can utilize the SPICE Kernels that spacecraft teams use to describe mission trajectories, and create virtual versions that can be followed along through the simulation. Using 3-D spacecraft models, the public can follow spacecraft missions shown with breathtaking realism within the immersive display. We have a detailed model of the Cassini spacecraft, and we are using the most recently updated SPICE kernels of Cassini, including the many Titan flybys, to show the public the fantastic journey of Cassini and Huygens in exploring Titan. In addition to the live lecturer, a second operator controls the Uniview software, allowing these flybys to be seen from any perspective deemed instructive and/or entertaining. Various Cassini and Huygens image data sets, including camera data, infrared spectrometer data and radar data, are being texture mapped and rendered on the moon’s surface. The atmosphere is visually peeled away, and various visuals are used together with an original script and musical score, both written by E/PO lead David Grinspoon, to explore themes of Titan and Astrobiology for the public. The visual content was directed by Dr. KaChun Yu, Curator of Space Sciences at DMNS, in collaboration with Dr. Grinspoon.
ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 -
Habitability of Water-Rich Environments – Task 1 – Improve and Test Codes to Model Water-Rock Interactions
Numerical codes have been developed to model chemical alteration of rocks by migrating fluids. One code is for alteration of permeable rocks by percolating fluids. Another code is for alteration of low-permeability rocks disrupted through hydro-fracturing by forming overpressured fluids. The codes could be used to model chemical weathering on Mars and Earth, and metasomatism on asteroids, moons, and planets.
ROADMAP OBJECTIVES: 2.1 2.2 -
Titan as a Prebiotic Chemical System – Benner
In 2007, NASA sponsored a committed of the National Academies of Science to explore whether life might exist in environments outside of the traditional habitable zone, defined as positions in a solar system where liquid surface water might be found. Alternative solvents which have analogous “habitable zones” farther away from their star include hydrocarbons, ammonia, and dinitrogen. The core question asked whether life having genetic biopolymers might exist in these solvents, which are in many cases (including methane) characterized by the need for “cold” (temperatures < 100K in the case of methane).
These “weird” solvents would require “weird” genetic molecules, “weird” metabolic processes, and “weird” bio-structures. In pursuit of this “big picture” question, we turned to Titan, which has exotic solvents both on its surface (methane-hydrocarbon) and sub-surface (perhaps super-cooled ammonia-rich water). This work sought genetic molecules that might support Darwinian evolution in both environments, including non-ionic polyether molecules in the first and biopolymers linked by exotic oxyanions (such as phosphite, arsenate, arsenite, germanate) in the second.
In the current year, we completed our studies that identified biopolymers that might work in hydrocarbon solvents. These studies have essentially ruled out biological processes in true cryosolvents. However, a series of hydrocarbons containing different numbers of carbon atoms (one, two, three, and four, for example, in methane, ethane, propane, and butane) cease to be cryosolvents as their chain lengths increase. These might be found on “warm Titans”. Further, they might exist deep in Titan’s hydrocarbon oceans, where heating from below would lead to warm hydrocarbon oceans.
These studies showed that polyethers are insufficiently soluble in hydrocarbons at very low temperatures, such as the 90-100 K found on Titan’s surface where methane is a liquid at ambient pressures. However, we did show that “warm Titans” could exploit propane (and, of course, higher hydrocarbons) as a biosolvent for certain of these “weird” alternative genetic biopolymers; propane has a huge liquid range (far larger than water). Further, we integrated this work with mineralogy-based work that allows reduced molecules to appear as precursors for less “weird” genetic biomolecules, especially through interaction with various mineral species, including borates, molybdates, and sulfates.
ROADMAP OBJECTIVES: 1.1 1.2 2.2 3.1 3.2 3.4 4.1 5.3 6.2 7.1 7.2 -
Habitability of Water-Rich Environments, Task 2: Model the Dynamics of Icy Mantles
One of Jupiter’s moons, Europa, is one of the few places in the solar system in which the physical and chemical conditions may be suitable for sustaining life. Europa is composed on an outer H2O layer, comprised of rigid ice overlying a liquid water ocean. It is this liquid water ocean which has been hypothesized as having the ingredients necessary for life, but it is shielded from our observation by the thick ice layer. However, under certain conditions, the ice layer is expected to undergo convection, possibly transporting chemicals from the liquid ocean to the surface, where we may be able to detect them. We perform computer modeling of ice/ocean convection to investigate how ocean material is carried up through the ice layer and whether it is expected to reach Europa’s surface. This work provides guidance for future missions which may probe the chemistry of the ice surface.
ROADMAP OBJECTIVES: 1.1 2.2 -
Titan as a Prebiotic Chemical System – Willacy
To develop a comprehensive model of the chemistry in Titan’s atmosphere including condensation of molecules onto grains and sublimation back to the gas, and exchange between the atmosphere and surface.
ROADMAP OBJECTIVES: 2.2 3.1 -
Fischer-Tropsch-Type Reactions in the Solar Nebula
Fischer-Tropsch-Type (FTT) reactions can form complex hydrocarbons via surface-mediated reactions using simple gases (CO, N2, and H2) on almost any grain surface and are currently being studied in relation to the early Solar Nebula. Several theories exist as to how hydrocarbons are formed in the early Solar System but the compelling nature of this type of reaction is that it is passive and generates a wide variety of complex hydrocarbons using commonly available components (gases/grains) without invoking a complex set of conditions for formation.
ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 -
Habitability of Water-Rich Environments – Task 5 – Evaluate the Habitability of Small Icy Satellites and Minor Planets
We constrained conditions of formation of silica phases in putative aqueous systems within the Saturn’s icy moon Enceladus, and evaluated the composition of aqueous fluids formed during thermal evolution and rock dehydration of the dwarf planet Ceres.
ROADMAP OBJECTIVES: 2.2 -
Fundamental Properties Revealed by Parent Volatiles in Comets
We studied water and other prebiotic molecules in the atmospheres of comets C/2012 S1 (ISON) and C/2013 R1 (Lovejoy). These projects aim at improved understanding of cometary chemistry – a test bed for the contribution of comets to the delivery of exogenous prebiotic organics and water to early Earth, hypothesized as a precursor event to the emergence of the biosphere.
ROADMAP OBJECTIVES: 2.2 3.1 4.3 -
Titan as a Prebiotic System Activity Report
We are calculating how much material, over time, is ejected from geysers on the moon Enceladus and ends up on the moon Titan, and how this material may be important for pre-biological chemistry on Titan.
ROADMAP OBJECTIVES: 2.2 3.1 3.2 3.3 -
Laboratory Investigations Into Chemical Evolution in Icy Solids From the Interstellar Medium to the Outer Solar System to Meteorites
NAI-GCA support in 2014 helped us continue our work on amino-acid stability. In 2014, we performed radiation experiments to measure the destruction rate of glycine in CO2 ice. In particular, we found that this rate depends on concentration and temperature, and is 20-40 times greater than for glycine in H2O-ice.
ROADMAP OBJECTIVES: 2.1 2.2 3.1 7.1 7.2 -
Long-Term Variation of High Energy Activity of Young Stars in Mass Accretion Outburst and Quiescence
High-energy photons in the young stellar environment are known to stimulate chemical reactions of molecules, producing prebiotic materials that might later be incorporated into comets and through them into young planets. Observational tests are sorely needed to assess the significance of such processing for Astrobiology, and to guide development of theoretical models for chemical evolution in protoplanetary environments.
ROADMAP OBJECTIVES: 2.2 3.1