Molecular asymmetry in prebiotic chemistry: The lesson of meteorites
Arizona State University, United States of America
We will give an account of the asymmetric effects that could have influenced the chiral symmetry breaking of molecules in cosmochemical environments and how they correlate with the data obtained from meteorite analyses. We also report on the crystallization behavior of isovaline, the most abundant non-racemic amino acid in the Murchison meteorite, and show how the findings exclude this amino acid’s attainment of enantiomeric excesses via phase changes such as crystallization or sublimation.
Internal water ocean on Titan: Place for prebiological and biological activity
Institute of Cytology, RAS, Russian Federation
Beneath the crust of Saturn's moon Titan may lurk a huge watery ocean, buried below several tens of kilometers of ice. The temperatures of the ocean could have been relatively warm and all conditions inside liquid body seem compatible with the emergence and sustaining of life. All requirements needed for exobiology - liquid water which exists within long geological period, complex organic and inorganic chemistry and energy sources for support of biological processes are on Saturnian moon.
Frozen Organic in Comets as Task for Bioastronomy
1Ilia State University, Georgia; 2Tbilisi Main Library, Georgia
Unidentified emissions are observed in spectra of comets. These lines and bands were not possible to be identified earlier. For solving the problem had developed the theoretical model of frozen hydrocarbon particles of icy halo of comets and described the mechanism of FHPs luminescence (Simonia, 2011). We have presented in this paper results of new investigations of frozen cometary organic as potential building blocks for bio substance. New concept of frozen cometary matter is proposed.
Frozen Organic in Comets as Task for Bioastronomy (Additional data)
1Tbilisi Main Library, Georgia; 2Ilia State University, Georgia
Unidentified emissions are observed in spectra of comets. These lines and bands were not possible to be identified earlier. For solving the problem had developed the theoretical model of frozen hydrocarbon particles of icy halo of comets and described the mechanism of FHPs luminescence (Simonia, 2011). We have presented in this paper results of new investigations of frozen cometary organic as potential building blocks for bio substance.
Radioracemization of 20 Amino Acids from the Beginnining of the Solar System
1Osservatorio Astrofisico di Catania, Italy; 2Instituto de Astrofisica de Canarias, Canary Islands, Spain; 3CSIC, Madrid, Spain
A series of chiral amino acids in the levo form used in the current terrestrial biochemistry were irradiated in the solid and dry state with γ radiation to a dose of 3.2 MGy which is the dose equivalent to that derived by radionuclide decay in comets and asteroids in one billion years at a depth >20m. For each amino acids the radiolysis degree and the radioracemization degree was measured respectively by differential scanning calorimetry (DSC) and by optical rotatory dispersion (ORD) spectroscopy.
Deuterium-rich Magnetic Nanographenes in Carbonaceous Chondrites
1Ecole Nationale Supérieure de Chimie de Paris, France; 2Université des sciences et technologies de Lille
Pulsed EPR shows that the structure of deuterium-rich radicals in the meteoritic IOM nicely corresponds to recent theoretical models on nanographenes. These radicals form a well defined population of nanographenes islands with electron density localized on zigzag edges separated by 2 nm, forming diradical states. D atoms are in benzylic position on side aliphatic chains. We conclude an interstellar origin for these nanographenes, with a D-enrichment posterior to their incorporation in the IOM.
Production of Oxidants by Ion Bombardment of Icy Moons in the Outer Solar System
1Centre de Recherche sur les Ions, les Matériaux et la Photonique, CIMAP – CIRIL – GANIL Caen France; 2Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Brazil; 3INAF-Osservatorio Astrofisico di Catania, Italy; 4IP&D/UNIVAP, São Jose dos Campos, SP, Brazil; 55Grupo de Física e Astronomia, CEFET/Química de Nilópolis, Brazil
We perform experiments on effects induced by fast ions colliding with solids of astrophysical interest. Ion energies vary from a few keV to hundreds MeV. We present the results obtained after ion irradiation of frozen water, carbon dioxide and their mixtures. Irradiation of mixtures result in the production of oxidants (hydrogen peroxide, ozone and carbonic acid). The results are discussed in the light of their relevance to support an energy source for biosphere on Europa and other icy moons.
Study of Meteoritic Impact-induced Chemistry in Titan Icy Surface using laser Thermal Shock laboratory Experiments
1Centro de Astrobiologia (CSIC-INTA), Torrejon de Ardoz, Madrid, Spain; 2SETI Institute, NASA Ames Research Center, Moffett Field, USA; 3NASA Ames Research Center, Moffett Field, USA; 4Institute of Physics, Academy of Science of the Czech Republic, Prague, Czech Republic; 5Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico D.F., Mexico
Meteoritic impacts should occur on Titan surface and products relevant to life could be formed on the surface from such processes. We present results of laboratory experiments carried out to examine the impact-induced chemistry on Titan. We have used a high-energy laser to recreate the energetic processes during impact shocks. We have examined the chemical changes of impacted tholins, the formation of complex organic compounds in the impacted ice as well as the vaporized gases from the ice.
Water ice mixed with various molecules and formed in the solar nebula
1Institute of Planetary Research, German Aerospace Agency (DLR), Germany; 2Astrophysical Institute and Observatory, Friedrich Schiller University, Germany
We have developed a multi-phase solar nebula model. At first, a quasi-stationary core is considered which allows molecule formation in the gas and ice phase on a timescale smaller than its lifetime. In the second phase we consider the gravitational collapse using a semi-analytical multi-zone solution of the hydrodynamic equations. Finally, the thin disk stage with a variable snowline is simulated to study differences between primordial ice formed in the core and fresh ice formed in the disk.
Titan's atmospheric chemistry at low temperature
Universidad Autonoma del Estado de Morelos, Mexico
We conducted a series of experiments on a simulated Titan’s atmosphere enriched with CO and subjected to electrical discharge irradiation at 136 K in a continuous flow regime. We identified hydrocarbons, nitriles and oxygenated compounds in gaseous phase and the formation of aerosol analogues. For the gaseous phase products we have estimated their energy yields, and for the aerosol analogues to determine their complex refractive index, based on transmittance and reflectance profiles.
Methanol Outgassing in the Jupiter-Family Comet 103P/Hartley 2
1National Taiwan Normal University, Taiwan, Republic of China; 2Academia Sinica, Institute of Astronomy and Astrophysics, Taiwan, Republic of China; 3NASA Goddard Space Flight Center, Maryland, USA
Observing cometary organic molecules provides fundamental knowledge on the formation of prebiotical organics in Solar Nebula. In support of EPOXI mission, we observed comet 103P during EPOXI flyby. An apparent temporal variation of CH3OH outgassing over days even hours was revealed. Both rotational temperature and production rate of CH3OH were found to be highest at perihelion. Our study is also crucial for determining the physical environment of 103P prior to EPOXI flyby and at the encounter.
Exploring the habitability of Mars and Europa using a glacial, sulphur-rich terrestrial analog
1University of Colorado at Boulder, United States of America; 2Geological Survey of Canada; 3Colorado School of Mines
We are exploring the potential for microbial life to use sulphur-redox reactions to gain energy on Mars and Europa by using a terrestrial analog site, an arctic glacier where sulphur compounds are a dominant energy source. We are investigating whether calculations of the energies that are available from different sulphur-redox reactions at this site can predict the specific sulphur-redox reactions that microbes there are using. This approach could assist future planetary mission planning.
Titan’s higher atmosphere composition from EUV solar occultation measurements
1Laboratoire Interuniversitaire des Systèmes Atmosphériques, Paris-Est Créteil and Paris Diderot universities, Créteil, France; 2Lunar and Planetary Laboratory, University of Arizona, Tucson, USA
Data from the UVIS instrument on board the Cassini orbiter and laboratory absorption cross section measurements were combined to study Titan’s upper atmosphere. Density profiles were derived for N2 and some hydrocarbons like CH4. A stable and slow solar occultation (T53 fly-by) was analyzed, resulting in an altitude resolution of a few km. The results of this study are expected to improve the knowledge of this region of the atmosphere and provide input for photochemical models.
More aromatic macromolecule in carbonaceous chondrite: an attempt to detect the intact composition of meteoritic organics without isolation
1Department of Earth and Space Science, Osaka University, Japan; 2Advanced Light Source, LBNL, USA; 3Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Japan; 4Fukuoka Institute of Technology, Japan; 5Yokohama National University, Japan; 6Tokyo University of Pharmacy and Life Sciences, Japan
The meteorite matrices were analyzed by micro-XANES spectroscopy in order to understand the intact compositions of organics in the Murchison meteorite. Aromatic carbon is more abundant in the meteorite matrices than that in the insoluble organic matter. The spectra of several different carbon regions in the matrices showed more heterogeneity in the functional group distributions than that observed in IOM, implying multiple chemical processes during the history of early solar system.
Origin Of Earth's Water: A Comparison Between Delivery By Planetary Embryos And Local Adsorption From Primordial Nebula
1Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii, United States of America; 2Center for Orbital dynamics, Univ. Estadual Paulista, Brazil
We present the results of a study of the origin of Earth’s water by comparing two scenarios: delivery by planetary embryos and adsorption from the primordial nebula. Our simulations indicate that a model based on the formation of Earth from grains on which water was adsorbed results in the accumulation of too much water in Earth. A more viable scenario seems to be a combination of the accretion of local grains with small amount of adsorbed water followed by a later delivery by planetary embryos.
Atmospheric entry of fluffy cometary particles under early Earth’s conditions.
1Observatoire de Paris / LERMA, 61 avenue de l’Observatoire, 75014 Paris, France; 2ISR-1, D-466, LANL, Los Alamos, NM- 87545 USA; 3LPI, 3600 Bay Area Blvd, Houston, TX-77058, USA; 4UPMC (Univ. Paris 6) / LATMOS, 4 place Jussieu, 75005 Paris, France.
We simulated the entry of compact spherical particles and aggregates of spherical grains through the early Earth’s atmosphere, with fractal aggregates representing fluffy cometary particles. The sizes range from 2 mm down to 200 µm. For a given volume, compact grains are more ablated than fractal aggregates, which better survive the atmospheric entry. Preliminary results suggest that complex organic molecules necessary for the development of life could have been delivered by cometary dust.
Could terrestrial pollen grains be transported to other planets?
1Instituto de Astronomia, Universidad Nacional Autónoma de México, Ensenada, B. C., Mexico; 2Instituto de Estudios Avanzados de Baja California, Ensenada, B. C., Mexico; 3Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, B. C., Mexico; 4Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Cd. Universitaria, D. F., Mexico; 5Centro de Astrobiología (INTA-CSIC), Torrejón de Ardoz, Madrid, Spain; 6Depto. de Investigación en Física, Universidad de Sonora, Hermosillo, Son., Mexico
We are studying the possibility that terrestrial pollen grains could be transported to other planets, via reverse Panspermia. We have analyzed the faith of debris ejected from Earth by means of numerical simulations of a large collection of particles. We also are studying the viability of pollen grains under extreme conditions. The entry of the transporter to the target planet will be also studied. Advances in each phase of this project are presented. Supported by CONACYT grant 128563 (Mexico).
Bayesian time series analysis of terrestrial impact cratering
Max Planck Institute for Astronomy
Giant impacts by comets/asteroids have probably influenced biological evolution. Some studies claims of a temporal periodicity in the cratering rate, but many of these studies have methodological problems. I develop a Bayesian method and use it to compare cratering models. The evidence supports a decrease up to the present in the impact rate over the past 250Myr for craters larger than 5km. This is consistent with a crater preservation/discovery bias. Periodic models are strongly disfavoured.
Aqueous alteration on minor bodies of the Solar System
LESIA-Obs. de Paris/Univ Paris Diderot-Sorbonne Paris Cité , France
I present a review on the data published in literature on the aqueous alteration process on Solar System minor bodies. 572 asteroids spectra are analysed to look for relationships between this process and the heliocentric distance, albedo and diameter of the bodies. The study of aqueous alteration is important for understanding the evolution of the early Solar System, as it can give information both on the thermal evolution of the asteroids and on the localization of water sources
MarcoPolo-R Near Earth Asteroid Sample Return Mission
1INAF - Astrophysical Observatory of Arcetri, Italy; 2LESIA - PAris Observatory, France; 3University of Nice, CNRS, OCA, France; 4MPS, Katlenburg-Lindau, Germany; 5INAF – Observatory of Roma, Italy; 6Leiden University, The Netherlands; 7Open Univ., Milton Keynes, UK; 8Open Univ., Milton Keynes, UK; 9IAA – CSIC, Granada, Spain; 10CRPG, Nancy, France
MarcoPolo-R is a sample return mission concept recommended by ESA as one of the concepts to be studied in the framework of Cosmic Vision medium size missions of opportunity for launch in 2022. MarcoPolo-R is a mission to a primitive Near-Earth Asteroid (NEA). It will rendezvous with a primitive NEA, scientifically characterize it at multiple scales, and return a unique unaltered sample to Earth for laboratory analyses. MarcoPolo-R scientific case and mission scenario will be here presented.
Icy Morphologies of Comet Tempel-1 imply past lake-habitats for Life
Cardiff Centre for Astrobiology (CCAB), United Kingdom
Icy morphologies seen in remnant lakes and centres of pedestal craters on Tempel-1 are dark because of cover by sublimation regolith. They imply melting of primordial dirty snow (fine grains of H2O, organics and clays) during an orbital phase closer to the Sun and via impact cratering. Ice areas began as depressed features, then evolve into elevated features due to faster evaporative erosion of the adjacent areas under unstable crusts. The comet thus had near-surface liquid water for periods.
OSIRIS-REx Asteroid Sample Return Mission: Exploring Our Past, Securing Our Future Through Pioneering Asteroid Science
1Lunar and Planetary Laboratory, University of Arizona, United States of America; 2NASA Goddard Space Flight Center, United States of America; 3Lockheed Martin, Canadian Space Agency, and many Universities and NASA Centers
The PI-lead Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) New Frontiers-3 mission has recently been selected by NASA. It will return the first pristine samples of carbonaceous material from the surface of a primitive asteroid. OSIRIS-REx’s target asteroid (101955) 1999 RQ36 is the most exciting, accessible volatile and organic-rich remnant from the early Solar System, as well as the most potentially hazardous asteroid known to humanity.