Publications 2019
Detection of water in the atmosphere of a small habitable-zone exoplanet
Thomas Greene (SSA) is a co-author on a paper submitted to the Astrophysical Journal Letters reporting the first-ever detection of water in the atmosphere of an exoplanet in the habitable zone of its star. The planet K2-18 is a sub-Neptune sized planet b discovered by the Ames Kepler / K2 mission. It is a low-density planet larger than Earth and smaller than Neptune, unlike any planet in our Solar System. However, it receives about the same amount of electromagnetic radiation from its star as we do from our Sun, so it has about the same temperature as Earth, about 280 Kelvins. Near-infrared Hubble Space Telescope (HST) data (points and error bars in the Figure) show the clear detection of water over 1.1 – 1.7 micron wavelengths. K2-18 b is unique in that all other low temperature (less than 600 Kelvin) planets have showed evidence of thick clouds that obscure water and most other features in Hubble transmission spectra. K2-18 b may be cold enough so that the materials producing those clouds are restricted to lower levels in its atmosphere, allowing the detection of water in its upper atmosphere that is probed by HST observations (P < 1 bar). This bodes well for the study of this and other cool planets with the more capable James Webb Space Telescope that is expected to launch in 2021. This work was also featured as the lead story on the “TWAN: This Week at NASA” youtube video on September 13, 2019.
No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals
Thayne Currie (SSA/NASA Sr. Postdoctoral Fellow) submitted a paper in Astrophysics, Earth and Planetary Astrophysics Jurnal on May 10, 2019, ApJL in press, arxiv:1905.04322.
The ExoEarth Yield Landscape for Future Direct Imaging Space Telescopes
Stark, C. C., Belikov, R (SSA)., Bolcar, M. R., Cady, E., Crill, B.P., Ertel, S., Groff, T., Hildebrandt, S., Krist, J., Lisman, P.D., Mazoyer, J., Mennesson, B., Menati, B., Pueyo, L., Rauscher, B.J., Riggs, A.J., Ruane, G., Shaklan, S.B., Sirbu, D.(SSA), Soummer, R., St. Laurent, K., Zimmerman, N. Accepted for publication in JATIS. Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM) arXiv:1904.11988 [astro-ph.EP]
Exoplanets Can’t Hide Their Secrets From Innovative New Instrument
Steve Howell (SSA) In an unprecedented feat, an American research team discovered hidden secrets of an elusive exoplanet using a powerful new instrument at the 8-meter Gemini North telescope on Maunakea in Hawai’i. The findings not only classify a Jupiter-sized exoplanet in a close binary star system, but also conclusively demonstrate, for the first time, which star the planet orbits. The breakthrough occurred when Steve B. Howell of the NASA Ames Research Center and his team used a high-resolution imaging instrument of their design — named ‘Alopeke (a contemporary Hawaiian word for fox). The team observed exoplanet Kepler-13b as it passed in front of (transited) one of the stars in the Kepler-13AB binary star system some 2,000 light-years distant. VISION TIMES. September 8, 2019
High-resolution Imaging Transit Photometry of Kepler-13AB
Steve B. Howell1 , Nicholas J. Scott1 , Rachel A. Matson1 , Elliott P. Horch2 , and Andrew Stephens3 1 NASA Ames Research Center, Moffett Field, CA 94035, USA; steve.b.howell@nasa.gov 2 Department of Physics, Southern Connecticut State University, 501 Crescent Street, New Haven, CT 06515, USA 3 Gemini Observatory, 670 North Aohoku Pl, Hilo, HI 96720, USA Received 2019 May 30; revised 2019 June 26; accepted 2019 July 2; published 2019 August 19. The Astronomical Journal, 158:113 (9pp), 2019 September
Characterizing Exoplanets Using High-Resolution Imaging
Steve Howell, Author of the Article entitled, published in Astrosociety, AstroBeat on May 2019. The discovery of exoplanets, planets orbiting alien suns, has led to a revolution in astrophysics. Today, one of the most exciting and challenging pursuits is to identify another planet similar to our Earth on which life might exist. The Earth, a small rocky planet, has liquid water on its surface, likely a necessary condition for life. Most exoplanet discoveries have been made via the transit technique (*see Glossary near the end) using NASA’s space-based telescopes Kepler/K2 and TESS. The observed transit allows one to measure the radius of the detected planet—assuming the size of the star it orbits is well known.
Detecting Unresolved Binaries in TESS Data with Speckle Imaging
Rachel A. Matson (SSA), Steve Howell (SS Division Chief) published a paper in The Astronomical Journal Journal, 157:211 (12pp), 2019 May. This paper is about The Transiting Exoplanet Survey Satellite (TESS) is conducting a two-year wide-field survey searching for transiting exoplanets around nearby bright stars that will be ideal for follow-up characterization. To facilitate studies of planet compositions and atmospheric properties, accurate and precise planetary radii need to be derived from the transit light curves. Since 40%–50% of exoplanet host stars are in multiple star systems, however, the observed transit depth may be diluted by the flux of a companion star, causing the radius of the planet to be underestimated. High angular resolution imaging can detect companion stars that are not resolved in the TESS Input Catalog, or by seeing-limited photometry, to validate exoplanet candidates and derive accurate planetary radii.
Photometric precision of a Si:As impurity band conduction mid-infrared detector and application to transit spectroscopy
Taro, M., Greene, T(SSA)., Johnson, R., McMurray, R., Roellig, T (SSA)., Ennico, K. (Submitted on 10 Sep 2019) arXiv:1909.04769 [astro-ph.IM]
The Calculated Infrared Spectra of Functionalized Hexamethylenetetramine (HMT) Molecules.
A paper co-authored by NAI ARC team members Partha P. Bera(SSA), Scott A. Sandford (SSA), Timothy J. Lee (SST), and Michel Nuevo(SSA) The paper describes the computed infrared spectra of functionalized hexamethylenetetramine (HMT) molecules. IR spectra of these families of molecules show characteristic IR bands that originate from the HMT framework vibrations, as well as unique features associated with the side groups. These IR features are strong and may allow them to be identified in space, most likely as a family of compounds much like PAHs. A related paper on the laboratory synthesis and identification of HMT and HMT-CH2OH in irradiated laboratory astrophysical ice analogs, co-authored by Christopher Materese, Michel Nuevo, Partha P. Bera, Scott A. Sandford, and Timothy J. Lee is currently in advanced production in Published on Oct 11, 2019 The Astrophysical Journal, Volume 884, Number 1
Polycyclic Aromatic Hydrocarbons with Armchair Edges: Potential Emitters in Class B Sources
Ricca, A. (SSA), Roser, J.E. (SSA), Peeters, E., Boersma, C (SSA): A recent publication by Ricca+ investigates the potential role of a subclass of very stable polycyclic aromatic hydrocarbon (PAH) species to the astronomical PAH signature. This work makes use of the data and tools provided by the NASA Ames PAH IR Spectroscopic Database and was supported through a NASA Directed Work Package titled: “Laboratory Astrophysics – The NASA Ames PAH IR Spectroscopic Database”. 2019, Astrophys. J, 882, 56
Cavity ring down spectroscopy of cold neutral phenanthrene and phenanthridine in supersonic jets.
Salma Bejaoui (SSA) and Farid Salama (SSA). Here we study the effect of nitrogen insertion on the electronic spectra of polycyclic aromatic hydrocarbon (PAH) molecules measured under laboratory conditions that are relevant for comparison with astronomical data. We examine the case of the substitution of carbon atoms by nitrogen atoms in the benzenoid skeleton of phenanthrene (C14H10), a prototype non-compact PAH. The vibronic transitions of the 21A1(S1) ← ÐX1A1(S0) electronic absorption band system of neutral phenanthrene (C14H10) and phenanthridine (C13H9N) molecules seeded in a supersonic free jet expansion of argon gas are measured in the 315-345 nm region using the cavity ring down spectroscopy (CRDS) technique. Additional measurements of the absorption spectra of the phenanthrene, phenanthridine, and 1,10-phenanthroline (C12H8N2) molecules isolated in 10-K solid argon matrices are also presented. The results obtained confirm that laboratory spectra of cold, isolated molecules obtained under astrophysically relevant conditions are required for a direct, unambiguous comparison with astronomical observations as well as for the understanding of the physical evolution of the interstellar medium. AIP Advances – Volume 9, Issue 8 — Accepted: 05 August 2019. Published Online: 21 August 2019
The Neutral Gas Properties of Extremely Isolated Early-type Galaxies III
Ashley, T., Marcum, P.M (SSA)., Alpaslan, M., Fanelli, M.N. & Frost, J.D., April 2019, The Astronomical Journal, 157, 158
The Fundamental Vibrational Frequencies and Spectroscopic Constants of the Dicyanoamine Anion, NCNCN- (C2N3-): Quantum Chemical Analysis for Astrophysical and Planetary Environments
Dr. David Dubois (NASA ARC/BAERI), Dr. Sciamma-O’Brien (NASA ARC/SSA) and Dr. Ryan Fortenberry (Univ. Mississippi) have a new article accepted in The Astrophysical Journal titled. We have performed high-level coupled cluster theory quartic force field (QFF) computations of C2N3- satisfying both computational cost and accuracy conditions. We provide for the first time accurate spectroscopic constants and vibrational frequencies for this ion. C2N3- could potentially exist and be detected in nitrogen-rich environments of the ISM such as IRC +10216 and other carbon-rich circumstellar envelopes, or in the atmosphere of Saturn’s moon Titan, where advanced N-based reactions may lead to its formation.
Gene Expression Measurement Module (GEMM) for Space Applications: Design and Validation
The first fully automated instrument for high-throughput biological experiments in space. Kianoosh Peyvan, Fathi Karoui, John J. Cooper, Jeff Chamberlain, Dominic Suciu, Michael Slota, Andrew Pohorille (SSX) Peyvan Systems Inc., Seattle, WA 98109, USA, University of California San Francisco, Department of Pharmaceutical Chemistry, San Francisco, CA 94158, USA, NASA Ames Research Center, Space Biosciences Research Branch, Moffett Field, CA 94035, USA, NASA Ames Research Center, Exobiology Branch, MS 239-4, Moffett Field, CA 94035, USA. Received 7 May 2019, Revised 5 July 2019, Accepted 7 July 2019, Available online 9 July 2019. Life Sciences and Space Research 22, 55-67 (2019).
High-Resolution Imaging Transit Photometry of Kepler-13AB
(Howell, Scott, Matson, Horch, Stevens) Using the high-resolution imaging instrument, ‘Alopeke, at the Gemini-N telescope, we obtained simultaneous 2-channel time-series observations of the binary exoplanet host star Kepler13-AB. Our optical observations were obtained during a transit event of the exoplanet Kepler-13b and light curves were produced using both speckle interferometric and aperture photometry techniques. Both techniques con_rm that the transiting object orbits the star Kepler-13A while di_erent transit depths are seen across the optical wavelength range, being _2 times deeper in the blue. These measurements, as well as mass determinations in the literature, are consistent with Kepler-13b being a highly irradiated gas giant with a bloated atmosphere. Our observations highlight the ability of high-resolution speckle imaging to not only assess binarity in exoplanet host stars but robustly determine which of the stars the transiting object actually orbits.
A Pathfinder for imaging exo-Earths
Thayne Currie (SSA/NASA Sr Postdoctoral Fellow) published an online paper on May 9, 2019. The paper is about SCExAO an instrument on the Subaru Telescope that is pushing the frontiers of what is possible with ground-based direct imaging of terrestrial exoplanets, explains Thayne Currie, on behalf of the SCExAO team. https://www.nature.com/articles/s41550-019-0773-
No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals,
Thayne Currie (SSA/NASA Sr. Postdoctoral Fellow) submitted a paper in Astrophysics, Earth and Planetary Astrophysics Journal on May 10, 2019, ApJL in press, arxiv:1905.04322.
Atmospheric CO2 levels from 2.7 billion years ago inferred from micrometeorite oxidation
O. R. Lehmer,(1,3,4*) D. C. Catling,(1,3) R. Buick,(1,3) D. E. Brownlee,(2,3) S. Newport (1), accepted to Science Advances. 1 University of Washington, Dept. Earth and Space Sciences, Seattle, WA, 98195, USA 2 University of Washington, Dept. Astronomy, Seattle, WA, 98195, USA 3 University of Washington, Astrobiology Program, Seattle, WA, 98195, USA 4 MS 239-4, Space Science Division, NASA Ames Research Center, Moffett Field, CA, USA The paper looks at iron-rich micrometeorites, which are sand-sized particles that fall to Earth, and how they can constrain atmospheric composition during entry. We find that CO2 levels on the early earth were likely much higher than modern. Perhaps 70% of the Earth’s atmosphere at 2.7 billion years ago was CO2.
Big on Change, Small on Innovation: Evolutionary Consequences of RNA Sequence Duplication
Andrew Plebanek (SSX-UCSF), Caleb Larnerd (SSX-NASA Intern Program), Milena Popović (SSX-BMSIS), Chenyu Wei (SSX-UCSF), Andrew Pohorille (SSX), Mark A. Ditzler (SSX). Journal of Molecular Evolution (2019) 87:240–253.
A Makerspace for Life Support Systems in Space.
Jessica E. Snyder (SST) and Lynn Rothschild (SST). To establish a human settlement on the moon or Mars, NASA needs reliable life support systems that efficiently use nonrenewable resources packed from Earth while relying increasingly on resources available locally in space – solar energy and biological resources. Equipment for the life support system will need repair during multiyear missions. Earth will resupply when possible, but the crew will also make components in their own habitat during the mission. Both mechanical and biological ultra-low size, weight, and power (UL-SWaP) devices satisfy such technology gaps to continually maintain a habitable atmosphere. As pioneers of rapid prototyping on limited resources, the maker community could propel space travel forward by developing technologies consistent with the needs of human missions: efficient (UL-SWaP), automated, networked, and modular. ScienceDirect Journal. Available online 11 July 2019.
Carbon isotopic composition of lipid biomarkers from an endoevaporitic gypsum crust microbial mat reveals cycling of mineralized organic carbon.
Linda Jahnke(SSX) and David Des Marais (SSX). Exobiology Branch, Space Science & Astrobiology Division, NASA‐Ames. Research Center, Moffett Field, CA, USA. Received: 13 March 2019. First published: 30 July 2019. DOI: 10.1111/gbi.12355
The Baseline Resolution of Aldo-Monosaccharide Enantiomers: Simplified GC-MS Analyses Using Acetal-Trifluoroacetyl Derivatives for Complex Samples
George Cooper (SSX) has a manuscript accepted for publication. The Journal of Chromatography B. Available online 8 August 2019, 121761
Chemiosmotic energy for primitive cellular life: Proton gradients are generated across lipid membranes by redox reactions coupled to meteoritic quinones
George Cooper (SSX and as a Co-author) has a manuscript accepted for publication. Scientific Reports (Nature). DOI: 10.1038/s41598-019-48328-5
Atmospheric CO2 levels from 2.7 billion years ago inferred from micrometeorite oxidation
Owen Lehmer (SSX) submitted a paper to the journal Science Advances.
Evaluating Biosignatures for Life Detection
Andrew Pohorille (SSX) submitted a paper to the journal Astrobiology.
The BASALT Research Program: Designing and developing mission elements in support of human scientific exploration of Mars.
Darlene Lim (SST), Abercromby, A.F.J., Kobs Nawotniak, S., et al. 2019. Astrobiology 19(3) DOI: 10.1089/ast.2018.1869
A science-driven analog of telecommunication architectures for human planetary exploration.
Miller, M.J., Miller, M.J., Santiago-Materese, D., Seibert, M.A., and Lim, D.S.S. (2019) Astrobiology 19:000-000; doi: 10.1089/ast.2018.1906.
Developing intra-EVA science support team practices for a human mission to Mars
Payler, S.J., Mirmalek, Z., Hughes, S.S., Kobs Nawotniak, S.E., Brady, A.L., Stevens, A.H, Cockell, C.S., and Darlene Lim (SST) (2019). Astrobiology 19:000-000; doi:10.1089/ast.2018.1846.
Requirements for portable instrument suites during human scientific exploration of Mars
Sehlke, A., Mirmalek, Z., Burtt, D., Haberle, C.W., Santiago-Materese, D., Kobs Nawotniak, S.E., Hughes, S.S., Garry, W.B, Bramall, N., Brown, A.J., Heldmann, J.L., and Darlene Lim (SST) (2019). Astrobiology 19:000-000. doi: 10.1089/ast.2018.1841
Developing future deep-space telecommunications architectures: a historical look at the benefits of analog research on the development of Solar System Internetworking for future human spaceflight
Seibert, M.A., Darlene Lim (SST), Miller, M.J., Santiago-Materese, D., and Downs, M.T. (2019). Astrobiology 19:000-000; doi: 10.108/ast.2018.1915.
Tactical scientific decision-making during crewed astrobiology Mars missions.
Stevens, A.H., Kobs-Nawotniak, S.E., Garry, W.B., Payler, S.J., Brady, A.L., Miller, M.J., Beaton, K.H., and Darlene Lim (SST), (2019). Astrobiology 19:000-000. doi: 10.1089/ast.2018.183
Carbon isotopic composition of lipid biomarkers from an endoevaporitic gypsum crust microbial mat reveals cycling of mineralized organic carbon
Linda Jahnke (SSX) and David Des Marais (SSX) have submitted a manuscript to the Geobiology journal for publications.
A low-diversity microbiota inhabits extreme terrestrial basaltic terrains and their fumaroles: implications for the exploration of Mars.
Cockell, C.S., Harrison, J.P., Stevens, A., Payler, S.J., Hughes, S.S., Kobs Nawotniak, S.E., Brady, A.L., Elphic, R.C., Haberle, C.W., Sehlke, A., Beaton, K.H., Abercromby, A.F.J., Schwendner, P., Wadsworth, J., Landenmark, H., Cane, R., Dickinson, A.W., Nicholson, N., Perera, L., and Darlene Lim, (SST). (2019). Astrobiology 19:000-000; doi: 10.1089/ ast.2018.1870.
Basaltic terrains in Idaho and Hawai‘i as planetary analogs for Mars geology and astrobiology.
Hughes, S.S., Haberle, C.W., Kobs Nawotniak, S.E., Sehlke, A., Garry, W.B., Elphic, R.C., Payler, S.J., Stevens, A.H., Cockell, C.S., Brady, A.L., Heldmann, J.L., and Darlene Lim (SST) (2019). Astrobiology 19:000-000; doi:10.1089/ast.2018.1847.
Opportunities and challenges of promoting scientific dialog throughout the execution of future science-driven extravehicular activity.
Kobs Nawotniak, S.E., Miller, M.J., Stevens, A.H., Payler, S.J., Brady, A.L., Hughes, S.S., Haberle, C.W., Sehlke, A., Beaton, K., Chappell, S., Elphic, R.C., Darlene Lim (SST) and the BASALT Team. (2019). Astrobiology 19:000-000; doi: 10.1089/ast.2018.1901.
BASALT Special Collection is available online
There are 13 papers and one commentary in this Special Collection, and they include leadership and contribution from Code S and T personnel. Ames PAO has prepared various products to support this release and the plan is to tie in with HQ efforts associated with the March 11 budget roll out.
The complete genome and physiological analysis of the Eurythermal Firmicute Exiguobacterium chiriqhucha Strain RW2 isolated from a freshwater microbialite widely adaptable to broad thermal, pH, and salinity ranges.
Richard Allen White III, Sarah A. Soles, Greg Gavelis, Emma Gosselin, Greg F. Slater, Darlene Lim (SST), Brian Leander and Curtis A. Suttle. 2019. Frontiers in Microbiology, Vol.9, doi: 10.3389/fmicb.2018.03189
Using science-driven analog research to investigate extravehicular activity science operations concepts and capabilities for human planetary exploration.
Beaton, K.H., Chappell, S.P., Abercromby, A.F.J., Miller, M.J., Kobs Nawotniak, S.E., Brady, A.L., Stevens, A.H., Payler, S.J., Hughes, S.S., and Darlene Lim (SST). (2019a). Astrobiology 19:000-000; doi: 10.1089/ast.2018.1861
Assessing the acceptability of science operations concepts and the level of mission enhancement of capabilities for human Mars exploration.
Beaton, K.H., Chappell, S.P., Abercromby, A.F.J., Miller, M.J., Kobs Nawotniak, S.E., Brady, A.L., Stevens, A.H., Payler, S.J., Hughes, S.S., and Lim, D.S.S. (2019b) Astrobiology19:000-000; doi: 10.1089/ast.2018.1912
Strategic planning insights for future science-driven extravehicular activity on Mars.
Brady, A.L., Kobs Nawotniak, S.E., Hughes, S.S., Payler, S.J., Stevens, A.H., Cockell C.S., Elphic, R.C., Sehlke, A., Haberle, C.W., Slater, G.F., and Lim, D.S.S. (2019). Astrobiology 19:000-000; doi: 10.1089/ast.2018.1850
Spatial distribution and preservation of carbon isotope biosignatures in freshwater microbialite carbonate.
Belan, M., Brady, A.L., Kim, S-T., Darlene Lim (SST)., Slater, G.F. 2019. ACS Earth and Space Chemistry: 3, 335-343. DOI: 10.1021/acsearthspacechem.8b00182.
Compendium of Astrobiology Classics: Perspectives on Foundational Texts
Sanjoy Som (SSX, BMSIS) published a book, (Habitable Press, January 2019). “This book assembles seven classical works of science spanning four centuries and relevant to the modern discipline of astrobiology. Each text is selected by a scientist who describes in accompanying perspectives the value of their choice to science and to themselves. Every individual featured in this compendium was once a stargazing child. This innate curiosity about the world around us drives our desire to find our place among the vast universe, and this book is an illustration of these efforts.”