Satgen 172 Meteor Scatter Bonanza - MAY BE ???? by GM4IHJ 12th July 92 Towards the end of August 1862 , Comet Swift Tuttle was a superb magnitude 2 comet easily visible in northern skies. Several astromers attempted to calculate its orbit , and the Italian astronomer Giovanni Schiaparelli was the first to point out that the orbit was very close to that of the famous August meteor shower - the PERSEIDS. With the recent passage of Halleys comet and the comet trails imaged by the IRAS Infra Red Astronomy satellite. The link between comet dust trails and meteor showers is now well established. So it is reasonable to ask "When is Comet Swift Tuttle expected back , and will it like Halley and several other comets produce big meteor shower events when the comet is nearest to the Earth" ? The trouble is that some astromers linked slight increases in the Perseids shower in the 1970's with Swift Tuttle likely return. But no comet was seen and some 1980's Perseids were very poor. But last year although Europe saw a relatively moderate Perseids shower, there was a sudden spectacular increase in the Perseids over Japan, where conditions were much more favourable than they were over Europe. So is Swift Tuttle coming back now ? Checks with old comet records suggest that Swift Tuttle which has only been seen once , may well be Comet Kegler last seen in 1737. So several astromers have plotted the likely returmn of a hypothetical Kegler Swift Tuttle and suggest it may indeed return this Autumn or Winter. Officially the Perseids begin to build up on 10th August with best reception likely around noon and midnight local Sun time ( not Daylight saving ), each day to 13th August. At these times a 45 degree elevation of the shower radiant from UK should give good results . But be aware that while the Perseids radiant is above the UK horizon through out the shower 10th to 13th August. The actually number of meteors intercepted by the Earth as it passes through the Comets Dust track has two marked peaks . One due at about 2200 UTC GMT on 11th August and maybe a second peak roughly around 1000 utc on 12th August, ie both peaks at times not far from those giving the best radiant location. Caution is however necessary . Comet Swift Tuttle has not yet been located If it is not going to appear until say December , it will not be in place to give us a good shower in August because its track will be quite some way from the Earth - making it a poor visual and a poor meteor track target. Despite the above " Loads of Caution". I would recommend those who can to tune to a German beacon 144.91 MHz DL0PR for the late evenings ( or any other beacon to your south east or south 28, 50 or 144 MHz). You can also tune to 48.249 for the carrier of the Madrid TV or 48.26 for South German TV. If the shower is any good you should see flashes of picture as your TV locks to these stations via a meteor trail. I hear the BBC TV may broadcast the Giotto encounter with Comet Grigg Skjellerup around 1500 BST on 10th July. So will put this bulletin out earlier than usual to try to give a day or so warning. 73 de GM4IHJ @ GB7SAN