Planetary Atmospheres

Jupiter and it’s Moon Io

Planetary atmospheres

The group’s work focuses on the impacts of cosmic dust in planetary atmospheres. Ablation of this dust produces layers of metal atoms and ions (around the 1 mbar pressure height), and the subsequent polymerization of metallic compounds leads to meteoric smoke particles. These particles can act as condensation nuclei for the formation of mesospheric clouds, and provide a reactive surface for heterogeneous catalysis. We carry out laboratory studies of the gas-phase kinetics of reactions involving metallic species, as well as studying particle formation, heterogeneous kinetics, and vapour deposition. John Plane is also a member of the science team for NASA’s MAVEN spacecraft, currently in orbit around Mars.

Highlights from the past 3 years:

* published a wide-ranging review of cosmic dust impacts on all planets and some moons in the solar system (Plane et al., 2018b)

* observed and modelled the impact of a close cometary flyby of Mars in 2014 (Schneider et al., 2015)

* made the first observations of a metallic layer around another planet: MAVEN observations of an Mg+ layer around Mars (Crismani et al., 2017)

* modelled the Mg+ and Mg layers around Mars, and showed that CO2 ice clouds above 60 km probably nucleate on metal-rich water ice particles (Plane et al., 2018a)

* studied the low-temperature condensation of CO2 on metal oxide nanoparticles at a facility at the Karlsruhe Institute of Technology, and demonstrated that this would only occur in the Martian atmosphere under exceptionally cold conditions (Nachbar et al., 2016)

* reported the very strange behaviour of metallic ions in the Martian ionosphere above 120 km, measured by a mass spectrometer on MAVEN (Grebowsky et al., 2017)

* showed that benzene forms from the cyclo-trimerization of acetylene on meteoritic particles, relevant for the troposphere of Saturn’s moon Titan (Frankland et al., 2016)

* showed that meteoric smoke catalyzes the oxidation of CO by O2 at temperatures above 450 K, which is relevant for the troposphere of Venus (Frankland et al., 2017)

Crismani, M. M. J., Schneider, N. M., Plane, J. M. C., Evans, J. S., Jain, S. K., Chaffin, M. S., Carrillo-Sanchez, J. D., Deighan, J. I., Yelle, R. V., Stewart, A. I. F., McClintock, W., Clarke, J., Holsclaw, G. M., Stiepen, A., Montmessin, F., and Jakosky, B. M.: Detection of a persistent meteoric metal layer in the Martian atmosphere, Nat. Geosci., 10, 401–404, 10.1038/ngeo2958, 2017.

Frankland, V. L., James, A. D., Carrillo-Sánchez, J. D., Nesvorný, D., Pokorný, P., and Plane, J. M. C.: CO oxidation and O2 removal on meteoric material in Venus’ atmosphere, Icarus, 296, 150-162, 10.1016/j.icarus.2017.06.005, 2017.

Frankland, V. L., James, A. D., Sanchez, J. D. C., Mangan, T. P., Willacy, K., Poppe, A. R., and Plane, J. M. C.: Uptake of acetylene on cosmic dust and production of benzene in Titan’s atmosphere, Icarus, 278, 88-99, 10.1016/j.icarus.2016.06.007, 2016.

Grebowsky, J. M., Benna, M., Plane, J. M. C., Collinson, G. A., Mahaffy, P. R., and Jakosky, B. M.: Unique, non-Earthlike, meteoritic ion behavior in upper atmosphere of Mars, Geophys. Res. Lett., 44, 10.1002/2017GL072635, 2017.

Nachbar, M., Duft, D., Mangan, T. P., Gomez-Martin, J. C., Plane, J. M. C., and Leisner, T.: Laboratory measurements of heterogeneous CO2 ice nucleation on nanoparticles under conditions relevant to the Martian mesosphere, J. Geophys. Res. – Planets, 121, 753-769, 10.1002/2015JE004978, 2016.

Plane, J. M. C., Carrillo-Sánchez, J. D., Mangan, T. P., Crismani, M. M. J., Schneider, N. M., and Määttänen, A.: Meteoric Metal Chemistry in the Martian Atmosphere, J. Geophys. Res.-Planets, 123, 695-707, 10.1002/2017je005510, 2018a.

Plane, J. M. C., Flynn, G. J., Määttänen, A., Moores, J. E., Poppe, A. R., Carrillo-Sanchez, J. D., and Listowski, C.: Impacts of Cosmic Dust on Planetary Atmospheres and Surfaces, Space Sci. Rev., 214, art. no. 23, doi.org/10.1007/s11214-017-0458-1, 2018b.

Schneider, N. M., Deighan, J. I., Stewart, A. I. F., McClintock, W. E., Jain, S. K., Chaffin, M. S., Stiepen, A., Crismani, M., Plane, J. M. C., Carrillo-Sanchez, J. D., Evans, J. S., Stevens, M. H., and Yelle, R. V.: MAVEN IUVS observations of the aftermath of the Comet Siding Spring meteor shower on Mars, Geophys. Res. Lett., 42, 4755-4761, 10.1002/2015gl063863, 2015.