ISSN:
1572-9672
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Conclusions Since all the models referred to above reproduce observations of zodiacal light, but vary considerably in their composition, it is clear that the ambiguities must be resolved if we are to achieve a reliable description of interplanetary matter. For such purpose we must acquire additional information on the following aspects of the problem: a) Scattering functions of non-spherical particles, studied either by optical or microwave experiments using particles in form and refractive index similar to the micrometeorites collected by sounding rockets. b) Brightness and polarization of zodiacal light obtained by sounding rockets and satellites. All ground measurements are disturbed by terrestrial airglow, but this difficulty will be overcome by measurements made from altitudes 〉 150 km. In addition to their greater reliability in representing zodiacal light, such observations will provide data within the regions of elongation between the corona and 20° and from 90° to 180°, as et almost unobserved. Any marked deviation of the observations from the prediction by the models referred to above would have importance for further study. c) Particle counts and electron density measurements by deep space probes. Although space probes can provide only samples, results will be significant for obtaining a better estimate of both numbers of electrons and the presence of small particles in interplanetary space. Especially must we determine whether there is only a cloud of small particles around the earth (Whipple, 1961b) or whether the submicron particles, as collected by Soberman et al., are spread out over a major region of the solar system. Such a solution would justify the application of Type III models. On the basis of the information outlined above, we might possibly find by optical methods models which, combined with our knowledge of the particulate content of space derived from meteorites and mechanical considerations (see Whipple, 1962a), would greatly enhance our understanding of the interplanetary media Such models might be similar to Type III but with a spatial variation in particle size and density distribution which also takes into consideration the properties of the Corona. It must be emphasized, however, that the present measurements and analyses do not warrant reliable conclusions about the electron density.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00225274
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