Thesis
An analysis of precipitating solar wind hydrogen at Mars: observations by the MAVEN spacecraft
University of Iowa
Master of Science (MS), University of Iowa
Autumn 2019
DOI: 10.17077/etd.005217
Abstract
Solar wind interactions at Mars have been an object of observation for decades and have played a major role in the evolution of the Red Planet since its formation. Containing extremely hot, fast, charged particles, the solar wind is capable of stripping away atmospheric gases from planets; this is especially true at Mars, which no longer has an intrinsic magnetic field shielding its atmosphere. Instead, the ionosphere, in combination with the interplanetary magnetic field, serves as a shield for the Martian surface by forming a bow shock, which prevents solar wind plasma from hitting the planet's surface by deflecting and slowing down the solar wind.
Like other planetary bodies, Mars has an atmosphere that extends well above its surface. Mars's atmosphere includes a large hydrogen corona that extends past its bow shock, where it can interact directly with the solar wind. As the solar wind passes through the corona, protons within the solar wind plasma may interact with exospheric hydrogen by means of charge exchange. During this interaction, a solar wind proton can strip an electron from a hydrogen atom, resulting in a neutral hydrogen atom propagating with essentially the same speed as the incident proton, but no longer subject to electromagnetic forces. This process allows these particles to make their way past the bow shock and deep into the magnetosheath and ionosphere of Mars, where some fraction of them are again ionized and can be detected by charged particle instrumentation. The purpose of this project is to understand and characterize the distribution and behavior of this penetrating proton population in the upper Martian atmosphere by utilizing data collected by the Solar Wind Ion Analyzer (SWIA) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft.
Details
- Title: Subtitle
- An analysis of precipitating solar wind hydrogen at Mars: observations by the MAVEN spacecraft
- Creators
- Sarah Henderson
- Contributors
- Jasper S Halekas (Advisor)Cornelia Lang (Committee Member)Vincent Rodgers (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Physics
- Date degree season
- Autumn 2019
- DOI
- 10.17077/etd.005217
- Publisher
- University of Iowa
- Number of pages
- vii, 47 pages
- Copyright
- Copyright 2019 Sarah Ann Henderson
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 45-47).
- Public Abstract (ETD)
The solar wind, composed primarily of electrons and protons, is a hot plasma that can interact with planetary bodies throughout our solar system. At Mars, solar wind ions can interact with the neutral hydrogen in Mars’s atmosphere and strip electrons from these hydrogen atoms. This charge exchange interaction results in a neutral hydrogen atom with solar wind speed. This resultant energetic neutral atom can continue to move past various boundaries created by Mars’s atmosphere and crustal magnetic fields, and these particles can ultimately penetrate deep into Mars’s ionosphere. Ultimately, these neutral atoms undergo charge-changing reactions again in the ionosphere and are therefore able to be detected by charged particle instruments on spacecraft. This project seeks to characterize the behavior of these energetic neutral solar wind hydrogen atoms as they enter the ionosphere of Mars using data collected by various instruments onboard the Mars Atmosphere and Volatile EvolutioN Mission (MAVEN) spacecraft.
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9983779899902771
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