Saturday, July 17, 2010

Tears of St. Lawrence

Folks, the annual Perseid meteor shower is upon us.  This is a major shower, and can be considered the best shower of the year.  The peak nights will be August 12/13th, and this year will be especially nice as the waxing crescent moon will set early in the evening.  It's typical for this shower to reach a zenithal hourly rate of 60+.


The Perseid meteor shower is associated with the comet Swift-Tuttle, and is so named because the radiant lies within the constellation Perseus.  This shower has been observed annually for about 2000 years. The Catholics named the shower the Tears of St. Lawrence, since the date of his martyrdom is August 10.  The average ZHR will probably be about 1 per hour for now, but as we near August 10 the ZHR could reach 15.


OK, so here's where to look, and how to look:
Perseus rises in the NW.  This time of year it should be well above the horizon around 1:00 AM (for mid-northern latitudes).  Did I say 1:00 AM?  Yeah, it's best viewing meteor showers between 1:00 and 4:00 AM.  Does that mean you can't see meteors before 1:00 AM?  Sure, you can - it's just ideal to observe in the wee hours of the morning.  Prepare for a meteor shower as you might for a night of fireworks.  I like to lay out a blanket, but a lawn chair would be nice.  Use bug repellent unless you want to have mosquitoes ruining the fun.  If you can manage, I think it's a good idea to grab a fan and turn it on you - the bugs will have a hard time getting to you that way.   As always, keep away from any direct source of light - meteors can be bright, but you still want to preserve your night vision for the fainter ones.  I should add that you don't have to look at Perseus to see the meteors - they will be all over the sky - just radiating from Perseus.  Look 20-40 degrees away from the radiant.  Have fun!