This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Friday, May 23, 2014

Camelopardalid meteor shower

In the lower right half of the image you can see the shape
of a giraffe and the location of the Camelopardalids meteor
shower tonight. Courtesy Science@NASA.
In the early hours of the morning May 24 (3-4 a.m. EDT and midnight and 1 a.m. PDT), a meteor shower from Comet 209P/LINEAR will dazzle observers with up to 1000 meteors per hour. This is a new shower, occurring five days before Comet 209P/LINEAR makes its closest approach to the earth (8 million kilometers) on May 29. The earth passes through the comets orbit, which is strewn with debris shed from the comet on previous passes. Amateur and professional observers are excited about the potential for this to be a "meteor storm", levels of 1,000 per hour, and many will be at telescopes or out on the lawn with pencil and paper counting them.
Plot of the Earth's path through the meteor shower
by Jeremie Vaubaillon.

Comet 209P/LINEAR was discovered on Feb. 3, 2004, by the Lincoln Near-Earth Asteroid Research (LINEAR) research project. It orbits around the sun with a period of roughly 5 years, with an aphelion out near Jupiter's orbit. As a result, calculations show that its orbit has been perturbed by the gravitational pull of Jupiter over the past few centuries, at least as far back as 1798. Most particles in the shower are smaller than a grain of sand and burn up high in the atmosphere.

Scientists are being cautious, predicting a few hundred meteors per hour to be on the safe side, but almost all of them express hope for the storm-level of 1000 per hour. Comet 209P/LINEAR is a small comet, and has in recent passes near the earth, a fairly low dust production. Observers in the United States and southern Canada are in the best position to see the shower.  The moon is a waning crescent, just four days from the dark new phase and will not be a hindrance.

Fred Whipple first developed the idea that comets were "dirty snowballs" orbiting the sun.The meteoroids are formed when a comet passes by the sun and some of the ice (water, methane, ammonia or other volatiles) sublimates, releasing the small silicate particles bound in it. The meteoroids spread out around the comet, eventually, after many passes by the sun, filling in the entire orbit.

Here is a link to Mikhail Maslov's website on the 2014 meteor shower, and here is a post by Robert Lunsford.

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