Astro 28E: Field Astronomy in the High Sierra - Lunar Grazing Occultation and the Fall Milky Way

Sept 27-29, 2002


Post-trip highlights

Our course was a great success! We had clear skies both nights and students got good views of the lunar graze Friday night from camp, thanks to our LIA Karl's 12" setup. Dave McKulle observed from the other side of the camp area with his 8" but had some tape recorder problems. I observed from a mile away and despite cold temperature-induced battery problems and dew, got a successful video record of multiple events.

Saturday morning started with my famous crepe breakfast; crepes made with vanilla soy and filled with fresh organic fruit, yogurt, and whipped cream. Nothing but the best for MY students. Here, Courtney carves up some fresh fruit while I work my magic in the crepe pan. Kevin seems to be enjoying his fruit-and-crepe breakfast.

After breakfast we loaded up and set out for a guided tour of the geology of the Sierra and comparisons with the geology of the other inner planets. I chose our first stop at a rare outcropping of metamorphic sedimentary rock amidst the pervasive granitics of the high Sierra, just above Alpine Lake. Here we went over the history of the Sierra for the past 120 million years, including the Cretaceous inland seas, the rise of the volcanic ranges, erosion, sedimentation in the seas again, and then the rise of the plutons of granite underneath the extrusive volcanics and their subsequent exposure in the last few million years. Mountain building happens on Venus as well, but Mercury and Mars do not have thin enough crusts for plate tectonics to happen today.

Back in the cars we caravaned over Ebbetts Pass, admired the first fall colors hitting the aspen groves as we approached Monitor Pass and the opening vistas of the Great Basin. Next stop was Fales Hot Creek - a stream of perfectly temperature'd hot water cascading through mini-waterfalls and pools north of Bridgeport. A brief sprinkle from thunderstorms made climbing into the steaming hot creek a delight, where I continued our lecture on the inner planet crustal processes, including the formation of hot springs and the nature of faulting. The Great Basin formed from the stretching of the earth's crust due to plate tectonics. The stretching caused faulting and the subsequent intrusion of water down into the hot interior of the earth. Asymmetric pressure caused mountains to rise and tilt, and for hot springs to form along these faulting areas. Springs are also now believed to have been discovered on Mars, although they are not as active as on Earth.

Saturday night included a delicious meal of pasta supplemented with fresh vege sauces from student contributions. Then we set up the 12" Dobsonian and studied the star formation regions of the Sagittarius spiral arm of our Milky Way Galaxy, which rides conveniently in the evening sky of the early autumn. Lectures on star formation and evolution around the telescope went on well into the night. Sunday morning started with another awesome crepe breakfast, followed by for solar study with the 8" Meade.

Here, I gathered the troops for sunspot viewing and a lecture on how magnetic fields inhibit the convective flow of heat from the solar interior and result in cool spots on the surface. The radiation laws then explain why these cool spots look so dark. The influence of sunspots on earth climate was described but not explained because.... we don't KNOW why they influence climate!







Below are some photos I pulled off of slides - the quick way; I just photographed them with the Dimage 5 by holding the slides up to a window and using the macro setting.

A rare outcrop of ancient volcanics in the Sierra - here above Bear Valley. Perfect place for a lecture on mountain building and the history of the Sierra

Fale Hot Creek. Leaning against a soft waterfall of piping hot water is a great place to listen to a lecture on the volanic history of the Eastern Sierra

Yes - A delightful spot - highlight of the trip for sure.