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Orgel, L, A'Hearn M, Bada J, Baross J, Chapman C, Drake M, Kerridge J, Race M, Sogin M, Squyres S.  2000.  Sample return from small solar system bodies. Advances in Space Research. 25:239-48.   10.1016/s0273-1177(99)00954-0   AbstractWebsite

With plans for multiple sample return missions in the next decade, NASA requested guidance from the National Research Council's Space Studies Board on how to treat samples returned from solar system bodies such as planetary satellites, asteroids and comets. A special task group assessed the potential for a living entity to be included in return samples from various bodies as well as the potential for large scale effects if such an entity were inadvertently introduced into the Earth's biosphere. The group also assessed differences among solar system bodies, identified investigations that could reduce uncertainty about the bodies, and considered risks of returned samples compared to the natural influx of material to the Earth in the form of interplanetary dust particles, meteorites and other small impactors. The final report (NRC, 1998) provides a decision making framework for future missions and makes recommendations on how to handle samples from different planetary satellites and primitive solar system bodies

Bada, JL, Glavin DP, McDonald GD, Becker L.  1998.  A search for endogenous amino acids in martian meteorite ALH84001. Science. 279:362-365.   10.1126/science.279.5349.362   AbstractWebsite

Trace amounts of glycine, serine, and alanine were detected in the carbonate component of the martian meteorite ALH84001 by high-performance liquid chromatography. The detected amino acids were not uniformly distributed in the carbonate component and ranged in concentration from 0.1 to 7 parts per million. Although the detected alanine consists primarily of the L enantiomer, low concentrations (<0.1 parts per million) of endogenous D-alanine may be present in the ALH84001 carbonates. The amino acids present in this sample of ALH84001 appear to be terrestrial in origin and similar to those in Allan Hills ice, although the possibility cannot be ruled out that minute amounts of some amino acids such as D-alanine are preserved in the meteorite.

McDonald, GD, Bada JL.  1995.  A Search for Endogenous Amino-Acids in the Martian Meteorite Eeta79001. Geochimica Et Cosmochimica Acta. 59:1179-1184.   10.1016/0016-7037(95)00033-v   AbstractWebsite

The Antarctic shergottite EETA 79001 is believed to be an impact-ejected fragment of the planet Mars. Samples of the carbonate (white druse) and the basaltic (lithology A) components from this meteorite have been found to contain amino acids at a level of approximately 1 ppm and 0.4 ppm, respectively. The detected amino acids consist almost exclusively of the L-enantiomers of the amino acids commonly found in proteins, and are thus terrestrial contaminants. There is no indication of the presence of alpha-aminoisobutyric acid, one of the most abundant amino acids in several carbonaceous chondrites. The relative abundances of amino acids in the druse material resemble those in Antarctic ice, suggesting that the source of the amino acids may be ice meltwater. The level of amino acids in EETA79001 druse is not by itself sufficient to account for the 600-700 ppm of volatile C reported in druse samples and suggested to be from endogenous martian organic material. However, estimates of total terrestrial organic C present in the druse material based on our amino acid analyses and the organic C content of polar ice can account for most of the reported putative organic C in EETA 79001 druse.

Brinton, KLF, Engrand C, Glavin DP, Bada JL, Maurette M.  1998.  A search for extraterrestrial amino acids in carbonaceous Antarctic micrometeorites. Origins of Life and Evolution of Biospheres. 28:413-424.   10.1023/a:1006548905523   AbstractWebsite

Antarctic micrometeorites (AMMs) in the 100-400 mu m size range are the dominant mass fraction of extraterrestrial material accreted by the Earth today. A high performance Liquid chromatography (HPLC) based technique exploited at the limits of sensitivity has been used to search for the extraterrestrial amino acids alpha-aminoisobutyric acid (AIB) and isovaline in AMMs. Five samples, each containing about 30 to 35 grains, were analyzed. All the samples possess a terrestrial amino acid component, indicated by the excess of the L-enantiomers of common protein amino acids. In only one sample (A91) was AIB found to be present at a level significantly above the background blanks. The concentration of AIB (similar to 280 ppm), and the AIB/isovaline ratio (greater than or equal to 10), in this sample are both much higher than in CM chondrites. The apparently large variation in the AIB concentrations of the samples suggests that AIB may be concentrated in rare subset of micrometeorites. Because the AIB/isovaline ratio in sample A91 is much larger than in CM chondrites, the synthesis of amino acids in the micrometeorite parent bodies might have involved a different process requiring an HCN-rich environment, such as that found in comets. If the present day characteristics of the meteorite acid micrometeorite fluxes can be extrapolated back in time, then the flux of large carbonaceous micrometeorites could have contributed to the inventory of prebiotic molecules on the early Earth.

Chen, RF, Bada JL.  1989.  Seawater and Porewater Fluorescence in the Santa-Barbara Basin. Geophysical Research Letters. 16:687-690.   10.1029/GL016i007p00687   Website
Becker, L, Bada JL, Kemper K, Suslick KS.  1992.  The Sonoluminescence Spectrum of Seawater. Marine Chemistry. 40:315-320.   10.1016/0304-4203(92)90029-a   AbstractWebsite

The sonoluminescence spectra of seawater and of a sodium chloride solution were determined by irradiation with ultrasound at 20 kHz. Ultrasound creates sonoluminescence through the process of acoustic cavitation: the formation, growth and implosive collapse of bubbles in a liquid. The sonoluminescence spectra of both seawater and NaCl in water are characterized by an emission line at 589 nm from excited-state sodium. Excited-state Na atoms are produced from the reaction of Na+ with high-energy hydroxyl radicals formed directly during the cavitation event. Emission at 589nm could be useful in determining whether sonochemical processes associated with cavitation occur in breaking waves or other turbulent flows.

Wills, C, iBada J.  2000.  The Spark of LIfe: Darwin and the Primeval soup. : Perseus publishing
Bada, JL, Miller SL, Zhao MX.  1995.  The Stability of Amino-Acids at Submarine Hydrothermal Vent Temperatures. Origins of Life and Evolution of the Biosphere. 25:111-118.   10.1007/bf01581577   AbstractWebsite

It has been postulated that amino acid stability at hydrothermal vent temperatures is controlled by a metastable thermodynamic equilibrium rather than by kinetics. Experiments reported here demonstrate that the amino acids are irreversibly destroyed by heating at 240 degrees C and that quasi-equilibrium calculations give misleading descriptions of the experimental observations. Equilibrium thermodynamic calculations are not applicable to organic compounds under high-temperature submarine vent conditions.

Bump, JK, Fox-Dobbs K, Bada JL, Koch PL, Peterson RO, Vucetich JA.  2007.  Stable isotopes, ecological integration and environmental change: wolves record atmospheric carbon isotope trend better than tree rings. Proceedings of the Royal Society B-Biological Sciences. 274:2471-2480.   10.1098/rspb.2007.0700   AbstractWebsite

Large-scale patterns of isotope ratios are detectable in the tissues of organisms, but the variability in these patterns often obscures detection of environmental trends. We show that plants and animals at lower trophic levels are relatively poor indicators of the temporal trend in atmospheric carbon isotope ratios (delta C-13) when compared with animals at higher trophic levels. First, we tested how differences in atmospheric delta C-13 values were transferred across three trophic levels. Second, we compared contemporary delta C-13 trends (1961 - 2004) in atmospheric CO2 to delta C-13 patterns in a tree species ( jack pine, Pinus banksiana), large herbivore (moose, Alces alces) and large carnivore (grey wolf, Canis lupus) from North America. Third, we compared palaeontological (approx. 30 000 to 12 000 14 C years before present) atmospheric CO2 trends to delta C-13 patterns in a tree species (Pinus flexilis, Juniperus sp.), a megaherbivore (bison, Bison antiquus) and a large carnivore (dire wolf, Canis dirus) from the La Brea tar pits ( southern California, USA) and Great Basin (western USA). Contrary to previous expectations, we found that the environmental isotope pattern is better represented with increasing trophic level. Our results indicate that museum specimens of large carnivores would best reflect large-scale spatial and temporal patterns of carbon isotopes in the palaeontological record because top predators can act as ecological integrators of environmental change.

Lazcano, A, Bada JL.  2008.  Stanley L. Miller (1930-2007): Reflections and Remembrances. Origins of Life and Evolution of Biospheres. 38:373-381.   10.1007/s11084-008-9145-2   AbstractWebsite

An appreciation of Stanley L. Miller, the pioneer prebiotic chemist, who died last year.

Bada, JL.  2001.  State-of-the-art instruments for detecting extraterrestrial life. Proceedings of the National Academy of Sciences of the United States of America. 98:797-800.   10.1073/pnas.98.3.797   Website
Botta, O, Bada JL, Gomez-Elvira J, Javaux E, Selsis F, Summons R.  2008.  "Strategies of life detection": Summary and outlook. Space Science Reviews. 135:371-380.   10.1007/s11214-008-9357-9   Website
Miller, SL, Bada JL.  1988.  Submarine Hot Springs and the Origin of Life. Nature. 334:609-611.   10.1038/334609a0   Website
Aubrey, A, Cleaves HJ, Chalmers JH, Skelley AM, Mathies RA, Grunthaner FJ, Ehrenfreund P, Bada JL.  2006.  Sulfate minerals and organic compounds on Mars. Geology. 34:357-360.   10.1130/g22316.1   AbstractWebsite

Strong evidence for evaporitic sulfate minerals such as gypsum and jarosite has recently been found on Mars. Although organic molecules are often codeposited with terrestrial evaporitic minerals, there have been no systematic investigations of organic components in sulfate minerals. We report here the detection of organic material, including amino acids and their amine degradation products, in ancient terrestrial sulfate minerals. Amino acids and amines appear to be preserved for geologically long periods in sulfate mineral matrices. This suggests that sulfate minerals should be prime targets in the search for organic compounds, including those of biological origin, on Mars.

Miller, SL, Bada JL.  1993.  Summary and Implications of Reported Amino-Acid-Concentrations in the Murchison Meteorite. Geochimica Et Cosmochimica Acta. 57:3473-3474.   10.1016/0016-7037(93)90551-7   Website
Glavin, DP, Bada JL.  2001.  Survival of amino acids in micrometeorites during atmospheric entry. Astrobiology. 1:259-269.   10.1089/15311070152757456   AbstractWebsite

The delivery of amino acids by micrometeorites to the early Earth during the period of heavy bombardment could have been a significant source of the Earth's prebiotic amino acid inventory provided that these organic compounds survived atmospheric entry heating. To investigate the sublimation of amino acids from a micrometeorite analog at elevated temperature, grains from the CM-type carbonaceous chondrite Murchison were heated to 550degreeC inside a glass sublimation apparatus (SA) under reduced pressure. The sublimed residue that had collected on the cold finger of the SA after heating was analyzed for amino acids by HPLC. We found that when the temperature of the meteorite reached apprx150degreeC, a large fraction of the amino acid glycine had vaporized from the meteorite, recondensed onto the end of the SA cold finger, and survived as the rest of the grains heated to 550degreeC. alpha-Aminoisobutryic acid and isovaline, which are two of the most abundant non-protein amino acids in Murchison, did not sublime from the meteorite and were completely destroyed during the heating experiment. Our experimental results suggest that sublimation of glycine present in micrometeorite grains may provide a way for this amino acid to survive atmospheric entry heating at temperatures >550degreeC; all other amino acids apparently are destroyed.

Becker, L, Evans TP, Bada JL.  1993.  Synthesis of C60h2 by Rhodium-Catalyzed Hydrogenation of C-60. Journal of Organic Chemistry. 58:7630-7631.   10.1021/jo00079a002   AbstractWebsite

Reduction of C60 with rhodium(0) on alumina and hydrogen in deuterated benzene (C6D6) at ambient temperature and pressure yields a mixture of hydrogenated compounds; C60H2 has been characterized as the major product in 14% yield based on H-1 NMR.