Astro Bob blog: Perseid meteor shower starts to heat up
By: Bob King, Duluth News Tribune
Perseid meteor shower starts to heat up
Wide open and breathtaking, the hills and buttes of northwestern South Dakota recall a lunar landscape but carpeted in green. Photo: Bob King
Hi everyone, great to be back. The past week I've been roaming South Dakota's Black Hills and the Badlands of North Dakota with my family. We also got in a serious game of miniature golf at the 18-hole Holy Terror Mini-golf course not far from Mt. Rushmore and saw some of the most barren, beautiful country in the world in far northwestern South Dakota. The sense of open space I felt reminded me of looking at galaxies on the darkest of nights. There's a vastness out there in the Dakotas that feels liberating to someone used to living in a city surrounded by forest. My astronomical activities were limited because there was so much else to do, but one morning at our campsite in the Black Hills I got up an hour before sunrise and shivered in my briefs to share a few minutes with Orion the Hunter as he topped the treeline.
AnnMarie, Stephen, Jim and Eric soak up some stellar photons during last night's observing session at the Korkki Road site north of Duluth. Part of the Milky Way can be seen at upper right. Details:16mm lens at f/4.0, 30 second exposure at ISO 3200. Photo: Bob King
Last night when we got home I couldn't shake off my wanderlust. I climbed back in the car again to join members the Arrowhead Astronomical Society for a night of observing at our dark sky site north of town. The sky is getting dark surprisingly early now that it's August. Back on the summer solstice in June, the last vestige of evening twilight departed the western sky around midnight. Now it's dark by 10:30. Morning twilight began at 2:30 then, but it now blooms in the east just before 4 -- a gain of over an hour. You can see this fattening of the night at the day's expense graphically in the illustration below.
This illustration shows at a glance how the number of hours of darkness have increased since the June 21 summer solstice. It's especially noticeable in the evening. Created with Chris Marriott's SkyMap software
Using a variety of telescopes, we looked at summer classics like the Ring Nebula, the Great Globular M13 in Hercules as well as Jupiter and Uranus. What struck us most however was all the activity from the Perseid meteor shower. The peak of this annual summertime favorite occurs next Thursday night August 12-13, but we easily spotted a dozen Perseids between us. These early arrivals seemed eager to get a head start in their race through Earth's atmosphere. Whether this bodes well for next week's peak or not I can't say. Given how unpredictable weather is, my advice is to get outside any clear night now through next weekend and have a look for yourself. We welcome your reports. Click on the Comments link and let us know what you're seeing.
On any given night, 7-10 "sporadic" meteors not associated with a particular shower randomly flash across the sky. You can tell a Perseid from a sporadic by tracing its path backwards. Any meteors that appear to originate from low in the northeastern sky below the familiar W of Cassiopeia are most likely Perseids. During early evening hours the constellation Perseus is rising from the atmospheric muck in that direction.
The sun from I-94 near Bismarck, North Dakota Thursday a few minutes before sunset. Photo: Bob King
We also remarked on Jupiter's early rising. The brilliant planet is now up by 10:30 p.m. in the eastern sky in Pisces. One last reminder, the evening planets Saturn, Mars and Venus are bunched closest together tonight in the west about 45 minutes to an hour after sunset. You'll find a handy locator / identifier map if you scroll to the end of my previous blog.