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Updated: Jul 12, 2026
11:34
Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
Summary
Mariner IV
Area of Science:
- Planetary Science
- Atmospheric Science
- Ionospheric Physics
Background:
- The Martian ionosphere presents unique characteristics distinct from Earth's.
- Understanding Mars's atmospheric composition and thermal structure is crucial for planetary science.
Purpose of the Study:
- To interpret Mariner IV ionospheric observations using a comprehensive atmospheric model.
- To characterize the Martian atmosphere's composition, temperature, and structure.
Main Methods:
- Analysis of ionospheric data from the Mariner IV mission.
- Development and application of an atmospheric model based on observed ion peak profiles.
- Identification of the ion peak as an F2 peak controlled by ambipolar diffusion.
Main Results:
- The Martian atmosphere is primarily composed of carbon dioxide.
- A very low surface temperature of 210 K was determined.
- The absence of a thermosphere and the presence of a tropopause at 14 km (140 K) were identified.
- Temperature decreases with altitude above the tropopause, following the solid carbon dioxide vapor-pressure curve up to 100 km (85 K), with an isothermal profile at higher altitudes.
Conclusions:
- The Martian atmosphere is characterized by extremely low temperatures and a distinct structure.
- The atmospheric model derived from ionospheric data provides key insights into Mars's thermal profile and composition.
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