Technical Analysis of Meteor
Data from Video Camcorder:
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Procedure: JVC DVL 9000 video digital camcorder was connected directly to a NAIT night-vision scope fitted with a 25 mm 1:1.3 lens. The night-vision detector was noted to be slightly more sensitive to small meteors than our eyes. The first data set was taped with camera pointed east, and a second set taken with the camera was pointed west. Not included in the data was a seperate record using a zoom setting to get a few rare close-ups. Data were complicated by cold batteries or tapes running out, however two good 30 minute continuous data sets were collected, beginning at 2:24:14 AM, and at 3:57:30 AM Mountain Standard Time. The tapes were then reviewed, and all detectable meteor events were noted with the time of their occurance. Non-Leonid meteors were excluded. Events were graded on a scale of 1-6 based on intensity, and the results logged on the graphs shown below.
The record shows a fairly continuous series of meteor events, with occasional pauses. The first data set detected 127 events, and the second data set detected 95 events, in a similar pattern. On several occasions events clumped together, however some large events appeared solitary. The rate of meteor detection appeared roughly steady throughout both records. (click graphs to enlarge to full screen)
To gain a better idea of how these objects were distributed in space at the time of their impact on the atmosphere, events were counted at regular 10-second intervals. The two data sets were analyzed seperately, but gave similar results, shown below. The stacked bar graphs below list the number of meteors detected every 10 seconds throughout the data runs. The different colors indicate the estimated intensity of the meteor, Blue = 1, Green = 2, Red = 3, Yellow = 4 and Orange = 5. Notice that certain colors appear to clump together, suggesting similar-sized chunks may be grouped together. (Click figures to enlarge.)
To see if any larger-scale structures were present, the same data were reviewed using a one minute window. On this scale too, there appears to be significant clustering of events. (On these graphs, the magnitude of the event was not noted.)
Finally, the timing between events was noted and projected in the frequency distributions shown below. Both data curves have a similar appearance, and suggesting peaks at about 0, 4, 18 and 95 seconds between events. (Again, the intensity of the event was not considered. Click on figures to enlarge.)
Finally, all the data were combined, including an additional 39 events taken from other data, to give a total of 261 events. Assuming a typical speed of about 40 miles per second, peaks in the distribution suggest an inhomogeneous meteor cloud with structures on a scale of about 4000 miles, 1000 miles and 150 mile clumps. The large number of events (about 18) occuring at less than one second apart suggest that additional fine structure may be present on a scale of a few tens of miles as well. This clumping may have been created by the initial events that ejected material from the comet Swift-Tuttle. Clouds might also be influenced by very weak intrinsic gravitational forces, or tidal interaction from passing next to large bodies such as the Earth.