P071-08
Outgassing Experiments on Carbonaceous Chondrites to Understand the Formation of Titan’s Atmosphere

Tuesday, 15 December 2020: 07:28
Virtual
Taylor Duncan1, Xinting Yu2, Maggie Thompson3 and Kyle Kim1, (1)University of California Santa Cruz, Earth and Planetary Sciences, Santa Cruz, CA, United States, (2)Johns Hopkins University, Department of Earth and Planetary Sciences, Baltimore, MD, United States, (3)University of California Santa Cruz, Astronomy and Astrophysics, Santa Cruz, CA, United States
Recorded Presentation
Abstract:
Titan is the only known moon in the Solar System with a substantial atmosphere of N2 and CH4, however, its origin and evolution are not well understood. Titan’s present amount of atmospheric CH4 was predicted to be destroyed photochemically on very short timescales compared to the age of the Solar System suggesting a resupply mechanism is necessary [1]. Cassini provided new insight into the origin of Titan’s atmosphere by measuring abundances of primordial noble gases and found that instead of being incorporated during formation, Titan’s atmosphere is likely linked to its interior [2][3]. Recent theoretical modeling of Titan’s atmosphere and interior [4][5] suggests that its atmosphere could have originated in part by outgassing of primordial organics in its interior. Insoluble organic matter (IOM) found in carbonaceous chondrites may serve as an analog for the organic material in Titan’s interior and provide experimental constraints on the outgassed component of its atmosphere. Therefore, outgassing experiments on carbonaceous chondrites can help inform how Titan obtained its secondary atmosphere, and in particular reveal a possible source for Titan’s atmospheric CH4. By heating primitive meteorite samples and measuring the abundances of their released volatiles, we may be able to connect what we see in the lab to species in Titan’s atmosphere today. In this study, we use samples of Murchison, a CM carbonaceous chondrite, which contains substantial amounts of insoluble organic matter (IOM).We heated 3 mg of powdered (20-100 µm and <20 µm) Murchison samples from room temperature to 1200° C in a furnace and continuously monitored 10 outgassed volatile species with a Residual Gas Analyzer (RGA). We plan to conduct additional experiments with other primitive meteorites and their extracted IOM to further investigate the link between outgassing of primitive materials and the origin of Titan’s atmosphere.

  1. Yung, Y. L., et al. 1984, Astrophys. J., 55, 465
  2. Niemann, H. B., et al. 2005, Nature, 438, 779
  3. Niemann, H. B., et al. 2010, J. Geophys. Res., 115, 65
  4. Miller, K. E., .et al. 2019, Astrophys. J., 871, 59
  5. Neri, A., et al. 2019, Earth Planet. Sci. Letts, 530, 6
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