The exospheres that surround airless bodies such as the Moon are tenuous, atmosphere-like layers whose constituent particles rarely collide with one another. Some particles contained within such exospheres are the product of direct interactions between airless bodies and the space environment, and offer insights into space weathering processes. NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) mission studied the Moon’s exospheric constituents in situ and detected a permanent dust exosphere1 of particles with radii as small as 300 nm. Here we present evidence from LADEE spectral data for an additional fluctuating nanodust exosphere at the Moon containing a population of particles sufficiently dense to be detectable via scattered sunlight. We compare two anti-Sun spectral observations: one near the peak of the Quadrantid meteoroid stream, the other during a period of comparatively weak stream activity. The former shows a negative spectral slope consistent with backscattering of sunlight by nanodust grains with radii less than 20 to 30 nm; the latter has a flatter spectral slope. We hypothesize that a spatially and temporally variable nanodust exosphere may exist at the Moon, and that it is modulated by changes in meteoroid impact rates, such as during encounters with meteoroid streams. The findings suggest that similar nanodust exospheres—and the particle ejection and transport processes that form them—may occur at other airless bodies.
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Horanyi, M. et al. A permanent, asymmetric dust cloud around the Moon. Nature 522, 324–326 (2015).
Colaprete, A. et al. An overview of the LADEE Ultraviolet-Visible Spectrometer. Space Sci. Rev. 185, 63–91 (2014).
Smith, S. M., Wilson, J. K., Baumgardner, J. & Mendillo, M. Discovery of the distant lunar sodium tail and its enhancement following the Leonid Meteor Shower of 1998. Geophys. Res. Lett. 26, 1649–1652 (1999).
Matta, M. et al. The sodium tail of the Moon. Icarus 204, 409–417 (2009).
McCoy, J. E. Photometric studies of light scattering above the lunar terminator from Apollo solar corona photography. In Proc. 7th Lunar Planet. Sci. Conf. Vol. 1, 1087–1112 (1976).
Glenar, D. A., Stubbs, T. J., McCoy, J. E. & Vondrak, R. R. A reanalysis of the Apollo light scattering observations, and implications for lunar exospheric dust. Planet. Space Sci. 59, 1695–1707 (2011).
Stubbs, T. J., Glenar, D. A., Colaprete, A. & Richard, D. T. Optical scattering processes observed at the Moon: predictions for the LADEE Ultraviolet Spectrometer. Planet. Space Sci. 58, 830–837 (2010).
Liu, Y. & Taylor, L. Characterization of lunar dust and a synopsis of available lunar simulants. Planet. Space Sci. 59, 1769–1783 (2011).
Krivov, A. V., Sremčević, M., Spahn, F., Dikarev, V. V. & Kholshevnikov, K. V. Impact-generated dust clouds around planetary satellites: spherically symmetric case. Planet. Space. Sci. 51, 251–269 (2003).
Stubbs, T. J. et al. The impact of meteoroid streams on the lunar atmosphere and dust environment during the LADEE mission. In Proc. 45th Lunar Planet. Sci. Conf. 2705 (2014).
McDonnell, J. A. M. et al. The dust distribution within the inner coma of comet P/Halley 1982i: encounter by Giotto’s impact detectors. Astron. Astrophys. 187, 719–741 (1987).
Sachse, M., Schmidt, J., Kempf, S. & Spahn, F. Correlation between speed and size for ejecta from hypervelocity impacts. J. Geophys. Res. Planet. 120, 1847–1858 (2015).
Simpson, J. A., Rabinowitz, D., Tuzzolino, A. J., Ksanfomaliti, L. V. & Sagdeev, R. Z. The dust coma of comet P/Halley—Measurements on the Vega-1 and Vega-2 spacecraft. Astron. Astrophys. 187, 742–752 (1987).
Sagdeev, R. Z., Evlanov, E. N., Fomenkova, M. N., Prilutskii, O. F. & Zubkov, B. V. Small-size dust particles near Halley’s Comet. Adv. Space Res. 9, 263–267 (1989).
Utterback, N. G. & Kissel, J. Attogram dust cloud a million kilometers from Comet Halley. Astron. J. 100, 1315–1322 (1990).
Hill, T. W. et al. Charged nanograins in the Enceladus plume. J. Geophys. Res. 117, A05209 (2012).
Mayer-Vernet, N. et al. Dust detection by the Wave Instrument on STEREO: nanoparticles picked up by the Solar wind? Sol. Phys. 256, 463–474 (2009).
Harder, J. W., Lawrence, G. M., Rottman, G. J. & Woods, T. N. Spectral Irradiance Monitor (SIM) for the SORCE mission. Proc. SPIE 4135, 204–214 (2000).
Shkuratov, Y., Starukhina, L., Hoffman, H. & Arnold, G. A model of spectral albedo of particulate surfaces: implications for optical properties of the Moon. Icarus 137, 235–246 (1999).
Johnson, P. B. & Christy, R. W. Optical constants of transition metals: Ti, V, Cr, Mn, Fe, Co, Ni, and Pd. Phys. Rev. B 9, 5056–5070 (1974).
Hapke, B. Theory of Reflectance and Emittance Spectroscopy 2nd edn (Cambridge. Univ. Press, 2012).
Taylor, L. A., Pieters, C. M., Keller, L. P., Morris, R. V. & McKay, D. S. Lunar mare soils: space weathering and the major effects of surface-correlated nanophase Fe. J. Geophys. Res. 106, 27985–27999 (2001).
Krüger, H., Krivov, A. V. & Grün, E. A dust cloud of Ganymede maintained by hypervelocity impacts of interplanetary micrometeoroids. Planet. Space Sci. 48, 1457–1471 (2000).
Grün, E., Zook, H. A., Fechtig, H. & Giese, R. H. Collisional balance of the meteoritic complex. Icarus 62, 244–272 (1985).
Molau, S. The AKM video meteor network. In Proc. Meteoroids 2002 Conf. 315–318 (ESA Publications Division, 2001); http://www.imonet.org/reports/201501.pdf
Sremcevic, M., Krivov, A. V. & Spahn, F. Impact-generated dust clouds around planetary satellites: asymmetry effects. Planet. Space Sci. 51, 455–471 (2003).
Gustafson, B. Å. S. Physics of zodiacal dust. Annu. Rev. Earth Planet. Sci. 22, 553–595 (1994).
Whipple, E. C. Potential of surfaces in space. Rep. Prog. Phys. 44, 1197–1250 (1981).
Angelopoulos, V. The ARTEMIS mission. Space Sci. Rev. 165, 3–25 (2011).
LADEE UVS was supported through the NASA Lunar Quest Program. The authors also acknowledge financial support from the LADEE Guest Observer Program and NASA’s Science Mission Directorate.
The authors declare no competing financial interests.
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Wooden, D., Cook, A., Colaprete, A. et al. Evidence for a dynamic nanodust cloud enveloping the Moon. Nature Geosci 9, 665–668 (2016). https://doi.org/10.1038/ngeo2779