Outgassing Experiments on Carbonaceous Chondrites to Understand the Formation of Titan's Atmosphere
Abstract
Titan is the only known moon in the Solar System with a substantial atmosphere of N 2 and CH 4 , however, its origin and evolution are not well understood. Titan's present amount of atmospheric CH 4 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 CH 4 . 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.
Yung, Y. L., et al. 1984 , Astrophys. J. , 55, 465 Niemann, H. B., et al. 2005, Nature, 438, 779 Niemann, H. B., et al. 2010, J. Geophys. Res. , 115, 65 Miller, K. E., .et al. 2019, Astrophys. J. , 871, 59 Neri, A., et al. 2019, Earth Planet. Sci. Letts , 530, 6- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMP071...08D
- Keywords:
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- 5210 Planetary atmospheres;
- clouds;
- and hazes;
- PLANETARY SCIENCES: ASTROBIOLOGY;
- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES;
- 6207 Comparative planetology;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 6281 Titan;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS