2010 Annual Science Report

NASA Ames Research Center Reporting  |  SEP 2009 – AUG 2010

Cosmic Distribution of Chemical Complexity

Project Summary

This project is aimed to improve our understanding of the connection between chemistry in space and the origin of life on Earth, and its possibility on other worlds. Our approach is to trace the formation and development of chemical complexity in space, with particular emphasis on understanding the evolution from simple to complex species. The work focuses upon molecular species that are interesting from a biogenic perspective and also upon understanding their possible roles in the origin of life on habitable worlds. We do this by first measuring the spectra and chemistry of materials under simulated space conditions in the laboratory. We then use these results to interpret astronomical observations made with ground-based and orbiting telescopes. We also carry out experiments on simulated extraterrestrial materials to analyze extraterrestrial samples returned by NASA missions or that fall to Earth in meteorites.

4 Institutions
3 Teams
12 Publications
1 Field Site
Field Sites

Project Progress

(1) In August 2010, we put on the web our collection of more than 600 polycyclic aromatic hydrocarbon (PAH) spectra together with the tools needed to query the data and analyze astronomical spectra (Figure 1). Three PAH-related papers were published to support missions such as Spitzer, SOFIA, Herschel, and JWST. Two other papers were published that describe a detailed lab study of the photochemical kinetics of several PAHs in cosmic ice analogs, providing the first solid state reaction rates needed to model extraterrestrial ice chemistry from the Solar System to the ISM. This novel modeling capability opens a new field of study.

Figure 1.. ​Poster announcing the NASA Ames PAH IR Spectroscopic Database and web site.

(2) We have published one paper and are working on others that describe the production of prebiotic compounds by UV irradiation of cosmic ices. The published paper appeared in Astrobiology and described work showing the photolysis of pyrimidine in H2O ices produces a host of new compounds, including the nucleobase uracil (Figure 2). A second paper in preparation shows that the addition of ammonia to the ice results in the production of the nucleobase cytosine.

Figure 2.. ​Irradiation of pyrimidine in H2O-rich ices results in the production of many new molecules, including the nucleobase uracil.

(3) Mission involvement- Co-I Sandford continues to be involved with the extraction, distribution, and analysis of samples from Comet 81P/Wild 2 returned by the Stardust mission (two related papers in the last year). He also continues to work as a Co-I on the Hayabusa asteroid sample return mission, which returned samples to Earth in June 2010 and is now actively studying these samples (Figure 3). Andrew Mattioda is a member of the Science Team for the O/OREOS (Organisms/ORganics Exposure to Orbital Stresses), NASA’s first Astrobiology Small Payloads mission. He and Nathan Bramall are working on the SEVO (Space Environment Viability of Organics) component for O/OREOS.

Figure 3.. ​Co-I Dr. Scott Sandford with the team that opened the Hayabusa sample return capsule (he is the person in the cleanroom suit to the farthest right)

This year Pascale Ehrenfreund (Wisconsin team), in collaboration with Co-Is Allamandola and Mattioda was awarded an NAI DDF grant to investigate the modification of organic materials (particularly PAHs) under interstellar conditions via UV-Visible spectroscopy. This DDF employs post-doctoral researcher Kathryn Bryson, who has set up the UV-Vis spectrometer system and has begun a spectroscopic study of thin films of astrobiologically interesting organic molecules.

    Louis Allamandola Louis Allamandola
    Murthy Gudipati

    Andrew Mattioda

    Scott Sandford

    Max Bernstein

    Jan Cami

    Jamie Cook

    Jason Dworkin

    Els Peeters

    Christiaan Boersma

    Nathan Bramall

    Michel Nuevo

    Joseph Roser

    Objective 1.1
    Formation and evolution of habitable planets.

    Objective 2.1
    Mars exploration.

    Objective 2.2
    Outer Solar System exploration

    Objective 3.1
    Sources of prebiotic materials and catalysts

    Objective 3.2
    Origins and evolution of functional biomolecules

    Objective 3.4
    Origins of cellularity and protobiological systems

    Objective 4.3
    Effects of extraterrestrial events upon the biosphere

    Objective 7.1
    Biosignatures to be sought in Solar System materials

    Objective 7.2
    Biosignatures to be sought in nearby planetary systems