Monday, September 1, 2008

One Year Ago...

A year ago this morning I left the house in Tucson about midnight, headed for Geology Vista - a pullout on the Mount Lemmon Highway north of Tucson. My quest that night was a transitory meteor shower called the Aurigids, so named because the meteors appear to originate from the constellation Auriga, north of Orion. An astronomical "telegram" (these days it is an e-mail!) had been sent out the day before alerting astronomers of a possible enhancement of the event. Normally this obscure meteor shower produces a few meteors per hour - in 2007, a near storm was predicted with rates up to 200 or more predicted!

Even though there was a nearly full moon in the sky, I reasoned that going to a higher elevation like Geology Vista (6500 feet elevation) might give cleaner air and provide a darker sky in which to observe. The peak of the shower was to happen between 4 and 5am, and I arrived early, trying several lenses to see which to use. I chose a wide angle zoom set to the widest angle, used wide open at F/3.5. The bright sky only allowed 30 second exposures, and I took one every 40 seconds, allowing a few seconds for the camera to write the file. Now realize meteors are about the hardest thing to photograph. While you know which constellation they are coming from, that still leaves a lot of sky and generally only the brightest meteors are recorded. Amazingly, about my 3rd exposure 2 meteors were caught in the same frame! In all I took over 100 exposures and captured 19 meteors - a great success percentage in my book.

Interestingly, by dawn's twilight, the peak had passed and a small crowd had gathered in the early morning hours. It is always fun to watch a meteor shower with a crowd - the oohs and aahs remind me of watching fireworks, which in a way, it really is... A single observer might miss some meteors, but a crowd is more likely to see them all. As a result, my unofficial count using the crowd showed a peak of about 250 per hour and the peak occurred about 30 minutes before predictions. Was it worth leaving a warm bed for yet another astronomical adventure? You bet!

No comments: