2015 Annual Science Report

NASA Goddard Space Flight Center Reporting  |  JAN 2015 – DEC 2015

Analysis of Prebiotic Organic Compounds in Astrobiologically Relevant Samples

Project Summary

The Astrobiology Analytical Laboratory (AAL) of the GCA is dedicated to the study of organic compounds derived from past and future sample return missions, meteorites, lab simulations of Mars, interstellar, proto-planetary, and cometary ices and grains, and instrument development. This year, we continued our work analyzing the organic content of carbonaceous chondrites, including analyses of amino acids, aliphatic amines, aldehydes and ketones. We investigated model systems for potentially relevant prebiotic chemistry. We supported the Biomolecule Sequencer project for evaluating DNA-analysis in microgravity environments by flying a MinIon device on the International Space Station. We continued to support development of protocols for a liquid chromatograph-mass spectrometer aimed at in situ analyses of amino acids and chirality on airless bodies, including asteroids and outer-planet icy moons (e.g., Enceladus and Europa). We participated in numerous public outreach and education events. We continued our participation in the OSIRIS-REx asteroid sample return mission and provided support for the Sample Analysis at Mars instrument of NASA’s Mars rover Curiosity.

4 Institutions
3 Teams
7 Publications
0 Field Sites
Field Sites

Project Progress

1) We have focused on better understanding the origin of meteoritic amino acids and their chiral excesses.
a. This year, we completed analysis of the amino acid distribution across the last of the carbonaceous chondrite groups, the CK meteorites and the related R chondrites. This work was published in Meteoritics & Planetary Science (Burton et al. 2015)

Figure 1: A comparison of structural distributions and abundances of C3 to C5 amino acids in a wide range of amino acid-containing meteorites analyzed in the AAL. The primary axis shows the fraction of C3 to C5 amino acids that are n-ω-isomers among the 8 carbonaceous chondrites groups, R chondrites, and ureilites. The secondary axis shows the total abundances of C3 to C5 amino acids in these meteorites (black diamonds, nmol/g). The proportion of amino acids present as n-ω-amino acids in the R and CK chondrites analyzed this year are very similar to the amino acid distributions of CO and CV chondrites and ureilites measured previously, and differ appreciably from aqueously altered CI, CM and CR chondrites. Figure from Burton et al. (2015).

b. We continued investigating the correlation between amino acids and the structurally related amines, expanding on our previous work and analyzing the Orgueil (CI1) carbonaceous chondrite. This was published in Meteoritics & Planetary Science (Aponte et al.), and presented at the Astrobiology Science Conference (AbSciCon 2015) and the Lunar and Planetary Science Conference (LPSC 2015). A manuscript on amines in Antarctic CM and CR chondrites is in preparation.

Figure 2: Relative abundances of amines and amino acids from the Orgueil and Murchison meteorites reflect different chemical and processing histories. (A.) Ratio of amine abundance to abundance of structurally analogous α-H-α-amino acids; (B.) Ratio of amine abundance to abundance of β, γ, and δ-amino acids and α-alkyl-amino acids (non-α-amino acids). A dashed line is shown for a ratio of 1:1. Figure from Aponte, J. C.; Dworkin, J. P.; Elsila, J. E. (2015).
Figure 2: Relative abundances of amines and amino acids from the Orgueil and Murchison meteorites reflect different chemical and processing histories. (A.) Ratio of amine abundance to abundance of structurally analogous α-H-α-amino acids; (B.) Ratio of amine abundance to abundance of β, γ, and δ-amino acids and α-alkyl-amino acids (non-α-amino acids). A dashed line is shown for a ratio of 1:1. Figure from Aponte, J. C.; Dworkin, J. P.; Elsila, J. E. (2015).

c. Further work on amino acid correlations are in development as we explore structurally related species, such as hydroxy acids, ketones, and aldehydes. Currently the preliminary results are not yet ready for publication.
d. The origin of lunar amino acids in Apollo samples was demonstrated to be primarily terrestrial contamination with some meteoritic input. This research was published in Geochimica et Cosmochimica Acta (Elsila et al. 2015), presented at AbSciCon 2015 and LPSC 2015, and received some media attention.
e. In an effort to understand the impact of energetic photons and particles on both sample analysis (x-ray tomography) and on samples in space (solar and galactic cosmic rays) we have a series of analyses in progress. We have determined that x-ray tomography has no impact on the amino acids in a meteorite; this work was published in Meteoritics & Planetary Science (Friedrich et al. 2016). The analysis of destruction of amino acids by natural energetic processing (cosmic rays) and effects on their chirality and carbon isotopic ratio is in progress, though several abstracts have been published. The results of this research will be important for interpreting the results on samples returned by Hayabusa2 and OSIRIS-REx.
f. We have participated in analyses of recent meteorite discoveries with large consortia. Manuscripts on the CM2-an Diepenveen and Howardite Sariçiçek are in preparation.
g. Based on preliminary data from our 2015 GCA URAA 2015 summer fellow, we are developing methods to use aromatic hydrocarbons as a probe into the organic chemistry of these same meteorites with our new NPP Fellow.
2) We have investigated model systems for potentially relevant prebiotic chemistry.
a. In collaboration with the Carnegie Institution of Washington alumni NAI team, we have investigated polyester alternatives to peptides, published in Origins of Life and Evolution of the Biosphere (Mamajanov et al. 2015).
b. We continue to compare ice chemistry with meteoritic compounds. Additional details on this work appear elsewhere in the GCA report (Cosmic Ice laboratory, R. Hudson et al.) and were published in Chemical Communications (Smith et al. 2015).
3) We continue to leverage our expertise and facilities to develop novel instrumentation for future spaceflight.
a. Though not directly funded by NAI, the contamination control and contamination knowledge efforts of OSIRIS-REx (launching 9/16) have benefitted from GCA expertise. We have published these in various abstracts, and a manuscript is in preparation.
b. GCA (A. Burton, J. Dworkin, M. Mumma) was instrumental in developing a partnership with Oxford Nanopore that has manifested in the Biomolecule Sequencer that will fly on the ISS in summer 2016 as a stepping stone to developing this technology for planetary astrobiology. It was highlighted in the Administrator’s state of NASA address, “In May, astronaut Kate Rubins launches to the ISS and plans to become the first person to perform DNA sequencing in space after she arrives at the Station.”
c. We continue to aid in the development of organic-sensing instrumentation for future missions, using liquid chromatography mass spectrometry and laser desorption/ionization mass spectrometry.
4) We continue to support Mars/SAM exploration via laboratory instrument analogs. Additional details can be seen in the Mars report and the manuscript listed below from Journal of Geophysical Research (Freissinet et al. 2015).
5) Finally, we contributed to the astrobiology community through organizing meetings.
a. Team members Dworkin and Elsila Cook served as members of the local and scientific organizing committees for “From Interstellar Ices to Polycyclic Aromatic Hydrocarbons – A symposium to honor Lou Allamandola’s contributions to the Molecular Universe” in Annapolis, MD (13-17 September 2015). This conference included participation from the Goddard, Ames, JPL, and SETI NAI teams.
b. Elsila Cook was on the scientific organizing committee and a plenary speaker for AbSciCon 2015, and Aponte organized a scientific session at the meeting. Dworkin and Callahan participated in AbSciCon social media events.