Distant interplanetary wake of Venus: plasma observations from pioneer Venus

Journal Article · Mon Nov 01 04:00:00 EST 1982 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA087iA11p09045· OSTI ID:6848526

Mihalov, J D; Barnes, A

In June 1979 the Pioneer Venus orbiter made its first series of passes through the distant solar wind wake of Venus at distances of 8--12 R/sub V/ behind the planet. During this period the plasma analyzer aboard the spacecraft detected disturbed magnetosheath plasma that intermittently disappeared and reappeared, suggesting a tattered, filamentary cavity trailing behind the planet. The magnetosheath dropouts almost always occurred inside the region of 'magnetotail' observed by Russell et al. Sporadic bursts of energetic ions (E/q> or approx. =4kV) are detected inside and, occasionally, outside the magnetotail; all such bursts are consistent with identification of the ion as O/sup +/ of planetary origin moving at the local magnetosheath flow speed. The morphology of the plasma dropouts and of the O/sup +/ bursts is analyzed in detail. The cavity appears to contract at times of high solar wind dynamic pressure. The intensity of the O/sup +/ component is highly variable, and appears not to be strongly correlated with solar wind dynamic pressure. The most intense bursts correspond to a flux < or approx. =10/sup 7/ ions cm/sup -2/ s/sup -1/. This maximum flux, if steady and filling a cylinder 1 R/sub V/ in radius would correspond to a mass loss rate of < or approx. =10/sup 25/ ions s/sup -1/; the intermittency and variability of the flux suggest that the true mean loss rate is very much lower. The kinetic temperature of the O/sup +/ component is estimated as 10/sup 5/--10/sup 6/ K in order of magnitude.

• Research Organization: Theoretical and Planetary Studies Branch, NASA Ames Research Center, Moffett Field, California 94035
• OSTI ID: 6848526
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 87:A11; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics &amp; Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHARGED PARTICLES
EARTH ATMOSPHERE
ION TEMPERATURE
IONS
MAGNETIC FIELD CONFIGURATIONS
MAGNETOSHEATH
MAGNETOSPHERE
MAGNETOTAIL
OXYGEN IONS
PIONEER SPACE PROBES
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
SPACE VEHICLES
VEHICLES
VENUS PLANET