Atomic Hydrogen on Mars: Measurements at Solar Minimum

  title={Atomic Hydrogen on Mars: Measurements at Solar Minimum},
  author={Joel S. Levine and David S. Mcdougal and D. E. Anderson and Edwin S. Barker},
  pages={1048 - 1051}
The Copernicus Orbiting Astronomical Observatory was used to obtain measurements of Mars Lyman-α (1215.671-angstrom) emission at the solar minimum, which has resulted in the first information on atomic hydrogen concentrations in the upper atmosphere of Mars at the solar minimum. The Copernicus measurements, coupled with the Viking in situ measurements of the temperature (170� � 30�K) of the upper atmosphere of Mars, indicate that the atomic hydrogen number density at the exobase of Mars (250… 
Three‐dimensional structure in the Mars H corona revealed by IUVS on MAVEN
Loss of water to space via neutral hydrogen escape has been an important process throughout Martian history. Contemporary loss rates can be constrained through observations of the extended neutral
On the escape of oxygen and hydrogen from Mars
Escape rates of oxygen atoms from dissociative recombination of O2+ above the Martian exobase are computed in light of new information from ab initio calculations of the dissociative recombination
Martian dayglow as seen by the SPICAM UV spectrograph on Mars Express
[1] In this paper we describe measurements of the Martian dayglow obtained by SPICAM UV spectrograph on board Mars Express between October 2004 and March 2005. Typical spectra (of more than 24,000
Photochemical escape of atomic C and N on Mars: clues from a multi-instrument MAVEN dataset
Context. Photochemical escape of hot atoms is crucial to the long-term evolution of the Martian climate. For atomic C and N, photochemical escape is primarily driven by photodissociation (PD) of CO
Airglow and Aurora in the Atmospheres of Venus and Mars
Measurements and models of the luminosity that originates in the Martian and Venusian atmospheres, including dayglow, nightglow and aurora, are compared. Most of the emission features considered
Morphology of the dayside ionosphere of Mars: Implications for ion outflows
[1] Significant fluxes of tailward streaming ions have been detected in the Martian wake by instruments on spacecraft. Imposing outward fluxes at the top of a model will produce dayside ion density
Morphology of the Near-Terminator Martian Ionosphere: A Comparison of Models and Data
[1] We have constructed low and high solar activity models of the Martian thermosphere/ionosphere for solar zenith angles from 60 to 90° in 5 degree increments. The solar fluxes that we have adopted
Models for Aurora and Airglow Emissions from Other Planetary Atmospheres
Models for aurora and airglow emissions from planetary atmospheres other than the Earth are surveyed, with emphasis on accomplishments of the last seven years. The goals of modeling the terrestrial
Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry
Context. Atmospheric escape has an appreciable impact on the long-term climate evolution on terrestrial planets. Exothermic chemistry serves as an important mechanism driving atmospheric escape and
Comparative Climatology of Terrestrial Planets
The early development of life, a fundamental question for humankind, requires the presence of a suitable planetary climate. Our understanding of how habitable planets come to be begins with the


Mariner 9 Ultraviolet Spectrometer Experiment: Initial Results
The ultraviolet airglow spectrum of Mars has been measured from an orbiting spacecraft during a 30-day period in November-December 1971 by measuring the spectral characteristics of particle scattering and the emission rates of the carbon monoxide Cameron and fourth positive bands.
Mariner 6 and 7 Ultraviolet Spectrometer Experiment: Analysis of hydrogen Lyman-alpha data
Four Lyman α airglow measurements of the limb and disc of Mars, made by ultraviolet spectrometers on Mariner 6 and 7 in 1969 and Mariner 9 in 1971, are analyzed to determine the amount and
Theoretical emergent Lyman alpha intensities from Mars
The behavior of the Lyman α 1216-A intensity on Mars is presented for a range of atomic hydrogen density distributions below 200 km. Two sets of radiative transfer calculations have been performed.
Composition and Structure of the Martian Atmosphere: Preliminary Results from Viking 1
Results from the aeroshell-mounted neutral mass spectrometer on Viking I indicate that the upper atmosphere of Mars is composed mainly of CO2 with trace quantities of N2, Ar, O, O2, and CO. The
Hydrogen Loss from the Terrestrial Planets
The idea of escape of light atmospheric gas is older than the kinetic theory, having been introduced by J. L. Waterston in 1846 (Chamberlain 1963). The thermal escape concept was revived by G. J.
Mars: An Evolving Atmosphere
  • M. McElroy
  • Physics, Environmental Science
  • 1972
The relative outgassing rates of H2O and CO2 on Mars are comparable with terrestrial values, although absolute rates for Mars are lower by a factor of 103.
OGO-5 measurements of the Lyman-alpha sky background in 1970 and 1971
The results of measurements of the Lyman-alpha sky background emission at 1216 A, made by two different UV photometers during the last three 'spin-up' maneuvers (enabling more than 50% of the sky to