Science Frontiers ONLINE No. 86: Mar-Apr 1993 | |
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All around the world, watching through the long nights, is a band of dedicated meteor observers -- mainly amateur astroomers. Collectively, they record many meteor showers and fireballs; all quite respectable astronomical objects. But sometimes fuzzy, rapidly moving luminosities appear, as in the following paragraph written by J.S. Gallagher:
"Diffuse luminous objects moving at angular velocities similar to those of meteors were observed during over 200 hours of meteor watching in 1991. They fell in three broad categories: arcs, patches, and 'meteors' similar in appearance to comet comas. Though I at first dismissed the possibility of their being related to meteors, I reconsidered this relation after eliminating other possible causes such as reflections from aircraft lights and tricks of vision. Their meteor-like behavior suggested that perhaps these events might be caused by clouds of exceedingly small meteoroids, visible only because of their numbers and compact grouping. Because such a formation would be unlikely to be maintained long in space, it appeared necessary that the particles involved must have maintained some weak physical contact until just prior to becoming visible. Perhaps some type of 'cosmic dust bunny,' disrupted by air resistance, might be the cause of these events."
These moving patches of light also resemble the "auroral meteors" cataloged under GLA3 in Lightning, Auroras, Nocturnal Lights. Physically, they might be related to the small, icy comets postulated by L.A. Frank to account for the transient "holes" seen in satellite ultraviolet images of the earth. (See SF#60 and #72 for more.)
(Gallagher, John S.; "Diffuse Luminous Objects Having Angular Velocities Similar to Meteors," Strolling Astronomer, 36:115, 1992. Cr. P. Huyghe)
References. The above phenomenon is cataloged in AYO8 under "Nebulous Meteors" in our book: The Sun and Solar System Debris. Ordering information for this book and Lightning, Auroras (mentioned above) may be found here.