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Small meteoroids' major contribution to Mercury's exosphere
1University of Texas at San Antonio, San Antonio, TX 78249, United States ; Southwest Research Institute, San Antonio, TX 78238, United States.
Icarus
|May 13, 2014
Summary
Small meteoroids significantly contribute to Mercury's exosphere. Meteoroids around 2.1 × 10-4 g produce the most vapor, with 90% of exospheric vapor originating from particles between 4.2 × 10-7 g and 8.3 × 10-2 g.
Area of Science:
- Planetary Science
- Exosphere Dynamics
- Impact Cratering
Background:
- Mercury's exosphere is a tenuous atmosphere.
- Meteoroid impacts are a significant source of exospheric material.
Purpose of the Study:
- To identify the meteoroid mass segments most responsible for refilling Mercury's exosphere.
- To quantify the contribution of meteoritic impact vaporization to Mercury's exospheric composition.
Main Methods:
- Utilized differential mass and velocity distributions for meteoroid populations.
- Applied impact rate calculations based on established methodologies.
- Determined vapor production per impact using theoretical frameworks.
Main Results:
- Meteoroids with a mass of 2.1 × 10-4 g were found to be the largest vapor contributors.
- 90% of total vapor production stems from meteoroids in the 4.2 × 10-7 g to 8.3 × 10-2 g mass range.
Conclusions:
- Specific meteoroid mass ranges are critical for maintaining Mercury's exosphere.
- Understanding impact vaporization is key to modeling exospheric evolution.
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