Interplanetary hydrogen and helium glow and the inferred interstellar gas properties

Technical Report · Tue Nov 01 04:00:00 EST 1983

OSTI ID:6588692

Judge, D L

Observations of the interplanetary hydrogen and helium glow have been obtained by a number of spacecraft and rocket experiments during the past fifteen years. Important results have been established on the temperature, density, velocity, spatial dependence, and hydrogen to helium ratio. However, only four spacecraft launched to date are investigating the outer solar system and of these four the Pioneer 10 spacecraft is the farthest out at 28 A.U. Observations from this spacecraft at great distances have permitted an improved analysis of the effects which are only evident at large distances from the Sun. Perhaps the most significant result in this regard is the clear evidence of the importance of multiple scattering of solar Ly-alpha. An effect which has not been observed in earlier work. Ignoring this effect can lead to a gross overestimate of the local galactic glow. Current best estimates of the galactic glow and the local interstellar wind parameters obtained by the Pioneer 10 photometer at great distances are presented, in addition to complementary experimental observations of particular interest.

• Research Organization: University of Southern California, Los Angeles (USA)
• OSTI ID: 6588692
• Report Number(s): N-84-13109
• Country of Publication: United States
• Language: English

Related Subjects

640105 -- Astrophysics & Cosmology-- Galaxies
640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC GASES
DISTRIBUTION
ELEMENTS
FLUIDS
GASES
HELIUM
HYDROGEN
INTERPLANETARY SPACE
INTERSTELLAR SPACE
LYMAN LINES
NONMETALS
PIONEER SPACE PROBES
RARE GASES
SOLAR ACTIVITY
SOLAR WIND
SPACE
SPACE VEHICLES
SPATIAL DISTRIBUTION
VEHICLES