Accession Number : AD0017237

Title :   PHOTOGRAPHIC METEOR ORBITS AND THEIR DISTRIBUTION IN SPACE

Corporate Author : HARVARD COLL OBSERVATORY CAMBRIDGE MASS

Personal Author(s) : WHIPPLE,FRED L.

Report Date : 30 SEP 1953

Pagination or Media Count : 30

Abstract : The orbits of 144 meteors were derived from double station photographs taken with rotating-shutter camaeras. Stream associations were obtained for 95 orbits comprising 21 streams; 2 of these constituted new cometary associations: periodic Tuttle 1926 IV and Mellish 1917 I. An association with Lowe 1913 I was considered probable. The data revealed no evidence for the occurrance of hyperbolic photographic meteor orbits. About 50% of the meteoroids of a constant mass coming to perihelion per year occurred in streams. Stream meteors constituted about 60% of those observed under average conditions throughout the year. The distribution of orbital elements (corrected for cosmic weights) among the sporadic meteors was similar to that of short-period comets. The cosmic weights were defined as proportional to the inverse probability that a meteoroid of a constant mass in a given orbit strikes the earth and is observed as a photographic meteor during a fixed time interval. Only 1 retrograde meteor orbit from 17 of the 51 sporadic orbits had an aphelion distance less than 8 au. A comet-asteroid criterion was utilized in an investigation of the asteroidal origin for some short-period streams. However, the major observational and theoretical evidence indicated a nonasteroidal origin for these streams.

Descriptors :   COMETS, DISTRIBUTION, HYPERBOLAS, INVERSION, MASS, METEOROIDS, METEORS, ORBITS, PERIHELION, PHOTOGRAPHS, PHOTOGRAPHY, PROBABILITY, SHORT RANGE(TIME), STATIONS, STREAMS, TIME INTERVALS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE