Meteor showers???

hey i heard there will be a meteor show next month, the 22nd i think. How do we know this, time and date? does the earth pass through at known area of meteors....or is there a load of them spotted on the way towords us from the outer solar system.....or what?? havnt a clue really and would love to know.. :oops:

hey i heard there will be a meteor show next month, the 22nd i think. How do we know this, time and date? does the earth pass through at known area of meteors....or is there a load of them spotted on the way towords us from the outer solar system.....or what?? havnt a clue really and would love to know.. :oops:

The reason we know is because of what causes Meteor showers, comets.

When you see the tails of comets they are full of bits of dust being blasted off the comet. So, if the earth passes near and orbit of a comet near to when a comet passed you get a shower. If you have a comet that has been going around for a very long time, like the periodic comets, then the dust has been deposited all around the orbit so each year you get a meteor shower while you pass close to the orbit, not just when the comet has been recently by.

The reason we have massive Leonid showers every 33 years is because that's the period of it's comet (Temple-Tuttle I believe) so every 33 years we pass close to the parent comet so we get a boost in Leonid numbers.

Hope that makes sense?

Bart.

Also, Griff, the shower you heard mentioned is the April Lyrids, with an expected peak on the night of April 21st/22nd this year I think. The associated parent comet is Comet Thatcher (C1861 G1), with a period of 416 years. Despite this long period for this comet, there is plenty of material left behind from its last and previous passes. You could expect to see almost 30 meteors per hour average maximum at the height of the shower, providing you have a clear dark observing site.

Neil,

The April Lyrids is definitely one of the lesser showers. The intensity of a shower is defined by a figure called the ZHR, or zenithal hourly rate. This specifies the number of meteors an experienced observer under perfectly clear and dark and moonless skies assuming the radiant (the point from which the meteors seem to eminate) is directly overhead the observer. The latter criteria is rarely met certainly from this part of the world. The IMO report the ZHR of the lyrids as 18 meteors per hour but do say this can be variable. To be fair you would be lucky to see any at all. There are far better meteor showers later in the year. For example the Perseids in August have a ZHR of 100 and peaks on August 13th this year. The December Geminids has a ZHR of 120 and is in my view the meteor highlight of the year. On many years past I have seen dozens and dozens of Geminid meteors even from light polluted Dublin. The peak this year is on December 14th at 16:45 (source International Meteor Organisation) however we should still see lots of meteors that night and also on the previous night.

By all means go out and look at the April Lyrids, just don't be too dissapointed if you don;t see any. The full list of meteor showers for the year is here;

www.imo.net/calendar/2007

However the IMO web server seems to be down as I type this.

Another of my favourites is the Orionids (peak October 21st, ZHR~25) Although the ZHR is quite low, the orionids are famed for bright persistent meteors.

Great stuff lads.

Thanks for the information, those 3 post gave me all i need to know, how , why and when.... !! perfect....another one of my long time astronomy question answered...


Oh Dave, cheers for the link tot he meteor shower calender...its up and running again......great info on it..... sorted for the rest of the year!!!