Satgen 372 Meteors = Satproblems? by GM4IHJ 11th May 96 The period from the 27th April to the 8th May 96 has provided some interesting but conflicting evidence for the role of Meteors in the production of, Sporadic E propagation (SpE) and, interference with VHF satellite uplinks and downlinks. The actual connection between meteoric dust and, SpE interference with satellites, is well documented. But recent events suggest that the connection may not be a direct one. This recent sequence of events was :- 27th and 28th April very strong SpE producing anomalously high levels of E layer ionisation during daylight resulting in reception of European TV in Scotland from stations in an arc from Slovakia to Spain. Together with enhanced 50 Mhz amateur band propagation and serious attenuation of links to and from satellites on 145 Mhz. There was no obvious rise in meteor activity either before or during these events. By contrast the period 3rd to 8th May produced very strong meteor scatter propagation between 0600 and 1100 ut each day. Audible pings were continuously received at these times even though the Eta Aquarid meteor shower never rose above 17 degrees here in Scotland. At the shower peak on 4th , European TV signals were locking pictures 2 or 3 times each minute. So this was by any standards a strong shower despite the fact that the Eta Aquarids comet - Comet Halley ,is now out beyond Saturn heading for aphelion furthest from the Sun, near Plutos orbit in 2024. There appear to be two possible explanations for the failure of these events to display any direct synchronism :- a. The dust causing summer time SpE may not be occasioned by individual meteor showers. It is possibly a consequence of the earths passage through the plane of the orbits of the major planets (in June and December). Noting that these major planets, gravitationally control most of the Inner solar system comets and hence produce a build up of dust in the plane of their planetary orbits. b. Or, there may be a time lapse between the the primary introduction of comet dust particles big enough to produce meteors, and the secondary collection and concentration by upper atmosphere jet streams of those particles of comet dust which are too small to burn up as meteors and stay in the upper atmosphere for weeks permitting their participation in the production of SpE. It remains to be seen whether the next few days will see strong SpE as a consequence perhaps of the smaller motes of comet dust brought into the upper atmosphere by the Eta Aquarids. If nothing happens this would strongly support the scenario outlined at a, in the paragraph above. PS. Grateful thanks to all those who sent me packet and email in connection with satgen 371. Whether you agreed or not with the need to build replacement mode A, K, KT and J analog amateur satellites.