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Determination of Meteor Parameters Using Laboratory Simulation Techniques

Published online by Cambridge University Press:  12 April 2016

J. F. Friichtenicht
Affiliation:
TRW Systems GroupRedondo Beach, California
D. G. Becker
Affiliation:
TRW Systems GroupRedondo Beach, California

Abstract

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Atmospheric entry of meteoritic bodies is conveniently and accurately simulated in the laboratory by techniques to be described which employ the charging and electrostatic acceleration of macroscopic solid particles in the 0.02 to 1 μ diameter range. Velocities from below 10 to above 50 km/s are achieved for particle materials which are elemental meteoroid constituents (e.g.: Fe, Si, Mg) or mineral compounds with characteristics similar to those of meteoritic stone (e.g.: FeTiO3). The velocity, mass, and kinetic energy of each particle are measured nondestructively, after which the particle enters a target gas region. Because of the small particle size, free molecule flow is obtained at target pressures ≦ 10 torr. At typical operating pressures (0.1 to 0.5 torr), complete particle ablation occurs over distances of 25 to 50 cm; the spatial extent of the atmospheric interaction phenomena (luminous trails, ionized wakes, etc.) is correspondingly small, simplifying many experiments. Procedures have been developed for measuring the spectrum of light from luminous trails and the values of fundamental quantities defined in meteor theory: heat transfer coefficient λ, drag coefficient Γ, ionization probability β, and photographic luminous efficiency τpg. Results of these measurements are presented, with emphasis on recent, improved evaluations of τpg and β over wide velocity ranges; it is shown that the laboratory values of τpg for iron are in excellent agreement with those for 9 to 11 km/s artificial meteors produced by rocket injection of iron bodies into the atmosphere. Also discussed in some detail is the relevance of these measurements to the interpretation of meteor observations and the methods of inferring from them numerical values of τpg and β for natural meteors.

Type
Research Article
Copyright
Copyright © NASA 1971

References

Allen, C. W., 1955. Astrophysical Quantities, 1st ed., Athlone Press, London, 178.Google Scholar
Ayers, W. G., McCrosky, R. E., and Shao, C.-Y., 1970. Photographic observations of 10 artificial meteors, Smithson. Astrophys. Obs. Spec, Rept., No. 317.Google Scholar
Becker, D. G., and Friichtenicht, J. F., 1971. Measurement and interpretation of the luminous efficiencies of iron and copper simulated micrometeors, Astrophys. J., 166, 699716.CrossRefGoogle Scholar
Becker, D. G., Friichtenicht, J. F., Hamermesh, B., and Langmuir, R. V., 1965. Variable-frequency radially-stable micrometeoroid accelerator, Rev. Sci. Instr., 36, 14801481.CrossRefGoogle Scholar
Ceplecha, Z., 1966. Dynamic and photometric mass of meteors, Bull. Astrom. Inst. Czech., 17, 347354.Google Scholar
Ceplecha, Z., 1968. Discrete levels of meteor beginning height, Smithson. Astrophys. Obs. Spec. Rept., No. 279.Google Scholar
Ceplecha, Z., and Padevět, V., 1961. The beginning of rapid evaporation of meteors of different dimensions, Bull. Astrom. Inst. Czech., 12, 191195.Google Scholar
Cook, A. F., Jacchia, L. G., and McCrosky, R. E., 1963. Luminous efficiency of iron and stone asteroidal meteors, Smithson. Contrib. Astrophys., 7, 209220.Google Scholar
Davis, J., 1963. On the color index of meteors, Smithson. Contrib. Astrophys., 7, 233236.Google Scholar
Davis, J., and Hall, J. E., 1963. Meteor luminosity and ionization, Proc. Roy. Soc. London, A, 271, 120128.Google Scholar
Derbeneva, A. D., 1966. Ionization coefficient for meteoritic atoms, Geomagnetizm i Aeronomiya, 6, 455457.Google Scholar
Friichtenicht, J. F., 1962. Two-million-volt electrostatic accelerator for hypervelocity research, Rev. Sci. Instr., 33, 209212.CrossRefGoogle Scholar
Friichtenicht, J. F., 1969. Evaporation of high-velocity particles in free-molecule flow, J. Am. Inst. Aeronaut. Astronaut, 7, 598601.CrossRefGoogle Scholar
Friichtenicht, J. F., and Becker, D. G., 1971. Measurements of the ionization probability of Cu and LaB6 simulated micrometeors, Astrophys. J., 166, 717724.CrossRefGoogle Scholar
Friichtenicht, J. F., Slattery, J. C., and Hansen, D. O., 1967. Ionization from Fe atoms incident on various gas targets, Phys. Rev., 163, 7580.CrossRefGoogle Scholar
Friichtenicht, J. F., Slattery, J. C., and Tagliaferri, E., 1968. A laboratory measurement of meteor luminous efficiency, Astrophys. J., 151, 747758.CrossRefGoogle Scholar
Furman, A. M., 1967. Meteor trail ionization theory, IV. Ionization efficiency through collision of vaporized meteoroid particles with air molecules, Astron. Zh., 10, 844853.Google Scholar
Hansen, D. O., and Roy, N. L., 1966. A solid-state low-noise preamplifier, Nucl. Instr. Methods, 40, 209212.CrossRefGoogle Scholar
Hersh, A. S., Friichtenicht, J. F., and Slattery, J. C., 1969. Drag coefficients of microscopic spheres in free molecule flow, in Rarefied Gas Dynamics, edited by Trilling, L. and Wachman, H. Y., Academic Press, New York, 1, 757766.Google Scholar
Hirschfelder, J. O., Curtiss, C. F., and Bird, R. B., 1954. Molecular theory of gases and liquids, J. Wiley and Sons, Inc., New York, Ch. 1.Google Scholar
McCrosky, R. E., and Soberman, R. K., 1963. Results from an artificial iron meteoroid at 10 km/sec, Smithson. Contrib. Astrophys., 7, 199208.Google Scholar
Millman, P. M., 1963. A general survey of meteor spectra, Smithson. Contrib. Astrophys., 7, 119127.Google Scholar
Millman, P. M., and Cook, A. F., 1959. Photometric analysis of a spectrogram of a very slow meteor, Astrophys. J., 130, 648662.CrossRefGoogle Scholar
Üpik, E. J., 1933. Atomic collisions and radiation of meteors, Acta et Commentat. Univ. Tartu (Dorpat), A26, No. 2.Google Scholar
Üpik, E. J., 1955. Meteor radiation, ionization, and atomic luminous efficiency, Proc. Roy. Soc. London, A, 230, 463501.Google Scholar
Üpik, E. J., 1958. Physics of Meteor Flight in the Atmosphere, Interscience Publishing Co., New York, 174 pp.Google Scholar
Roy, N. L., and Becker, D. G., 1971. A time interval selector and proportional delay generator, Rev. Sci. Instr., 42, 204209.CrossRefGoogle Scholar
Seares, F. H., and Joyner, M. C., 1943. Effective wave lengths of standard magnitudes; color temperature and spectral type, Astrophys. J., 98, 302330.CrossRefGoogle Scholar
Shelton, H., Hendricks, C. D. Jr., and Wuerker, R. F., 1960. Electrostatic acceleration of microparticles to hypervelocities, J. Appl. Phys., 31, 12431246.CrossRefGoogle Scholar
Sida, D. W., 1969. The production of ions and electrons by meteoric processes, Monthly Notices Roy. Astron. Soc, 143, 3747.CrossRefGoogle Scholar
Slattbry, J. C., and Friichtenicht, J. F., 1967. Ionization probability of iron particles at meteoric velocities, Astrophys. J., 147, 235244.CrossRefGoogle Scholar
Slattery, J. C., Friichtenicht, J. F., and Hamermesh, B., 1964. Interaction of micrometeorites with gaseous targets, J. Am. Inst. Aeronaut. Astronaut., 2, 543548.CrossRefGoogle Scholar
Tagliaferri, E., and Slattery, J. C., 1969. A spectral measurement of simulated meteors, Astrophys. J., 155, 11231127.CrossRefGoogle Scholar
Verniani, F., 1965. On the luminous efficiency of meteors, Smithson. Contrib. Astrophys., 8, 141172.CrossRefGoogle Scholar
Verniani, F., 1970. Structure and fragmentation of meteoroids, Space Sci. Rev., 10, 230261.CrossRefGoogle Scholar
Verniani, F., and Hawkins, G. S., 1964. On the ionizing efficiency of meteors, Astrophys. J., 140, 519564.CrossRefGoogle Scholar
Whipple, F. L., and Hawkins, G. S., 1959. Meteors, Handbuch der Physik., 52, 519564.Google Scholar