Heads up for the Orionids

[mike.brightmore]

A few recent reports suggest that this year's Orionid Meteor Shower will put on a reasonable display (always a bit of a lottery with meteor showers). Expect to see them between 17th and 25th October with the peak after midnight on 21st October. More information on this link... A Meteor Shower in Orion | One-Minute Astronomer

[Steve922]

What makes 'the reports' think there will be a decent showing this year?

Steve

[Starman]

The Orionids show quite a complex variation in their peak activity and have given decent displays over the past few years certainly exceeding their normal 20-25 ZHR figure. 2006 and 2007 for example showed peak rates of 50-70 while 2008's was up in the high 30's. The Moon is new this year so, as long as the clouds stay out of the way, the view should be pretty optimal. The peak activity for the Orionids is not sharply defined like it is for some showers and the peak activity can sustain over the course of several nights.

[Talitha]

Steve, i'd read an explanation of meteor shower variances a number of years ago and would like to share it. To the best of my memory, here's what it basically said. (Someone please correct me if there's any mis-information, ok? Thx!)

Meteor showers occur when our orbit places Earth in a position to cross a trail of debris left by a comet (or asteroid, IIRC). We know which comets are responsible for specific meteor showers, and i'm pretty sure some of the comets (if not all?) are periodic. That is to say, their return is quite predictable, like the famous Halley's Comet.

Since they return again and again, they leave multiple debris trails which, for some reason, can vary in the amount of debris left behind. It went on to explain that we don't always pass through the same trail, and this is why some meteor showers are more active than others. For example, the article i read was about a specific year, and a specific shower (Leonids?). It said that year, Earth would be passing through the debris trail the comet left behind in the 1700's (again, i hope my memory is recalling this correctly).

I hope this scant bit of information helps explain the basics of why meteor showers can vary from year to year. Hopefully someone who knows about it can contribute a more accurate and complete explanation.