Is there a daily variation in the observed influx of small comets?
Yes, there is. The maximum rate of atmospheric holes is observed from about 10 a.m. to 11 a.m. This maximum is two to three times greater than the event rate at 6 p.m. There is a good reason for this. First consider a uniform stream of small comets directed parallel to the Earth’s orbital motion and travelling 10 km/s relative to Earth. Of course, the small comets are all influenced by the Earth’s gravitational field when they are close to our planet. In the evening the small comet trajectories are more-or-less parallel to the gravitational force. The comets speed up but they are not deflected very much as they plunge toward the atmosphere. On the other hand, trajectories passing over noon are directed almost perpendicular to the gravitational field and they will be significantly bent toward the atmosphere and thus “gravitationally focused.” So the impacts on the dayside atmosphere, including the effects of gravitational focusing, will be confined to local times at the equator extendin
