The electron density profile of the outer corona and the interplanetary medium from Mariner-6 and Mariner-7 time-delay measurements

摘要: The round-trip propagation time delays to the Mariner-6 and Mariner-7 spacecraft were measured over a 6 month period, including occultations by solar corona during April May of 1970. interplanetary medium was sampled range ray impact parameters from about 5 100 radii. Electron density models fitted observations show that profile falls off nearly exactly as inverse square distance 10 radii out Earth's orbit. estimated values slopes are : 2.05 2.08 for Mariner-7, respectively. formal standard deviation on each estimate is +- 0.24. In general, densities factor 2 smaller than those determined eclipse photometric measurements. latter result agrees with recent radio ray-bending pulsar time-delay fluctuations in true electron at given point 100% local mean density. evaluations profiles 1 AU yield 9 3 electrons cm/sup -3/ both experiments, which analyzed independently. Our results strictly correctmore » only if general-relativistic effects predicted Einstein's general theory.« less