“Production and Characterization of Carbonaceous Laboratory Analogs of Planetary Atmospheric Aerosols, Surface Materials, and Cosmic Grains“
Joint Earth and Planetary Sciences and Astrobiology talk, as a part of the Whole Earth Seminar series.
Speaker: Dr. Ella M. Sciamma-O’Brien, NASA Ames Research Center, Space Sciences and Astrobiology Division, Moffett Field, CA.
Date: Tuesday, May 7, 2024
Time: 3:30pm
Location: Nat Sci Annex 101 & Zoom (link)
Carbonaceous dust and aerosols have been observed in planetary and interstellar/circumstellar environments. Dedicated laboratory experiments have been developed to produce analogs of these solid materials under different experimental conditions (molecular precursors, temperature, pressure, energy source…). These experimental studies are key to investigating the physical and chemical processes that drive the formation of solid particles from gas and solid phase molecular precursors in planetary and astrophysical environments. These experiments also allow the characterization of the physical, chemical, morphological, and optical properties of the solid laboratory-generated analogs, hence providing critical information that can be used as input parameters in models for the analysis and interpretation of observational data (e.g. optical constants, spectral features, grain morphology).
As an example of these laboratory efforts, I will present various studies that combine (1) experiments producing analogs of (exo)planetary atmospheric aerosols and cosmic grains from gas phase molecular precursors using the NASA Ames COSmIC facility, and (2) the characterization of these analogs with the NASA Ames Optical Constant Facility (OCF) to provide the real, n, and imaginary, k, parts of their refractive indices spanning the range from the visible to the far-infrared (0.59–200 µm, 16,950–50 cm−1) to the planetary and astrophysical communities. I will show how important these studies are for the interpretation of observational data and also introduce the NASA Center for Optical Constants whose overarching goal is to support a stable, long-term, synergistic laboratory effort to develop a comprehensive database containing complex refractive indices of laboratory-generated analogs of organic refractory materials, and ices present in planetary atmospheres and surfaces.
About the speaker:
Ella M. Sciamma-O’Brien is a research space scientist at NASA Ames Research Center. After graduating in 2007 with a PhD in plasma physics and electrical engineering, Dr. Sciamma-O’Brien shifted her focus to planetary science and laboratory astrophysics. For the last 13 years, Dr. Sciamma-O’Brien has been working on the NASA Ames Cosmic Simulation Chamber (COSmIC), leading the Titan Haze Simulation experiments to simulate Titan’s atmospheric chemistry at low temperature, and developing new applications for other (exo)planetary bodies and circumstellar envelopes. In recent years, she has developed the Optical Constant Facility (OCF) at Ames for the optical characterization (visible to far-IR) of various solid materials relevant to astrophysical and (exo)planetary applications. She is the task lead for the Laboratory Astrophysics Directed Work Package and the NASA Center for Optical Constant, the PI of an NFDAP project to explore Pluto’s surface composition, and Co-I on several CDAP projects to study cloud formation in Titan’s atmosphere.