Lunar Gravitational Focusing of Meteoroid Streams and Sporadic Sources
Recent work on the gravitational focusing of meteoroid streams and their threat to satellites and astronauts in the near-Earth environment has concentrated on Earth acting as the gravitational attractor, totally ignoring the Moon. Though the Moon is twelve-thousandths the mass of the Earth, it too can focus meteors, albeit at a much greater distance downstream from its orbital position in space. At the Earth–Moon distance during particular phases of the Moon, slower speed meteoroid streams with very compact radiant diameters can show meteoroid flux enhancements in Earth’s immediate neighborhood. When the right geometric alignment occurs, this arises as a narrowed beam of particles of approximately 1,000 km width. For a narrow radiant of one-tenth degree diameter there is a 10-fold increase in the level of flux passing through the near-Earth environment. Meteoroid streams with more typical radiant sizes of 1° show at most two times enhancement. For sporadic sources, the enhancement is found to be insignificant due to the wide angular spread of the diffuse radiant and thus may be considered of little importance.
KeywordsMeteor flux Gravitational focusing
Unable to display preview. Download preview PDF.
- H. Betlem, P. Jenniskens, P. Spurny, G. Docters Van Leeuwen, K. Miskotte, C. R. Ter Kuile, P. Zarubin, C. Angelos, Precise trajectories and orbits of meteoroids from the 1999 Leonid meteor storm. Earth Moon Planets 82–83, 277–284 (2000)Google Scholar
- N. Divine, Meteoroid focusing at a planet. JPL Interoffice Memorandum 5217-92-86 (1992)Google Scholar
- N. Divine, E. Grun, P. Staubach, Modeling the meteoroid distribution in interplanetary space and near-Earth. Proceedings of the first European conference on space debris, ESA SD-01 (1993), pp. 245–250Google Scholar
- M. H. Kaplan, Modern Spacecraft Dynamics and Control (John Wiley & Sons, New York, 1976), pp 91–95Google Scholar
- G. E. Peterson, Dynamics of Meteor Outbursts and Satellite Mitigation Strategies (The Aerospace Press, El Segundo, 1999), pp 75–100Google Scholar