Journal article
Prolonged Lifetime of the Transient Ionized Layer in the Martian Atmosphere Caused by Comet Siding Spring
Journal of geophysical research. Planets, Vol.125(11), e2020JE006607
11/2020
DOI: 10.1029/2020JE006607
Abstract
In October 2014, the close encounter between Mars and comet Siding Spring produced a transient ionized layer in the upper atmosphere composed primarily of Mg+ and Fe+ ions. The layer was detected by instruments on three spacecraft, including the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) on Mars Express. Analyses of the MARSIS data indicated the transient layer persisted up to 19 h after the comet's closest approach. We report MARSIS observations that suggest the transient layer lasted at least 7 days—and potentially as long as 32 days—after closest approach. During this period, the transient layer was mostly confined to a narrow latitude range between 20°N and 60°N and a longitude range spanning 275°E to 95°E. Since this period coincided with a highly active Sun, we discuss how solar flares may have contributed to the layer's prolonged lifetime.
Plain Language Summary
In October 2014, comet Siding Spring flew by Mars and produced a meteor shower that deposited a large amount of material in the planet's upper atmosphere. This material produced a layer of plasma in the Martian ionosphere, composed primarily of magnesium ions. Observations from multiple spacecraft detected this layer, and implied that it lasted 2 days after closest approach of the comet. We report new observations suggesting the layer lasted at least 7 days, and potentially up to 32 days after closest approach. Our results help to constrain models of metal ion chemistry in the Martian upper atmosphere.
Key Points
The transient ionospheric layer at Mars caused by comet Siding Spring's flyby may have lasted at least 7 days and up to 32 days
All detected transient layer measurements were located between 20°N and 60°N latitude, and most were confined to one longitudinal hemisphere
We discuss how solar flares may have contributed to the prolonged lifetime of the transient layer
Details
- Title: Subtitle
- Prolonged Lifetime of the Transient Ionized Layer in the Martian Atmosphere Caused by Comet Siding Spring
- Creators
- Z. A. Luppen - University of IowaZ. Girazian - University of IowaD. D. Morgan - University of IowaA. J. Kopf - University of IowaF. Chu - University of IowaJ. S. Halekas - University of IowaD. A. Gurnett - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Planets, Vol.125(11), e2020JE006607
- DOI
- 10.1029/2020JE006607
- ISSN
- 2169-9097
- eISSN
- 2169-9100
- Number of pages
- 13
- Language
- English
- Date published
- 11/2020
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428768302771
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