Rings of Earth

The authors have used the planetary radar at the Jet Propulsion Laboratory's Goldstone Tracking Station to monitor small particles of orbital debris. This radar can detect metallic objects as small as 1.8 mm in diameter at an altitude of 600 km. The results of the first set of observations show a flux (at 600 km) of 6.4 objects per square kilometre per day, of equivalent size of 1.8 mm or larger. Forty percent of the observed particles appear to be concentrated into one or two orbits. An orbital ring with the same inclination as the radar (35.1 degrees ) is suggested. However, an orbital band with the much higher inclination of 66 degrees is also a possibility. Neither explanation is without difficulty.<
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