(meteorobs) More meteorite news and pix

[Bruce McCurdy]

    The adventures of the meteorites of Lone Rock / Buzzard Coulee (official name yet to be determined)  continue. The samples Frank Florian and I recovered were, with the land owner's permission, returned to Edmonton and immediately turned over to the University of Alberta for analysis. After examination with the electron microprobe and comparison to other meteorites in the University's collection it has been classified as an H4 chondrite. 

    A thin section was sliced from one of the golfball-sized specimens and polished down to just 30 microns thickness. It was my privilege to attend the lab one day with Dr. Erin Walton of the Department of Earth and Atmospheric Sciences and view this thin slice through a top-notch microscope. While I'm used to observing beautiful astronomical objects through a telescope, this experience at the eyepieces of a microscope was a real eye-opener. When illuminated with cross-polarized light, this carefully-prepared slice of what had initially been a lumpy gray rock revealed intricate structural detail and an extraordinary range of colours that took my breath away. 

    For your viewing pleasure I have added a few photomicrographs to the website http://skyriver.ca/astro/bruce/meteorite.htm , including a couple of prime focus images provided by Dr. Walton and a couple of eyepiece projection shots taken by myself. (Scroll down near the bottom of the page.)  

    The University has just completed its measurement of radioactivity from short-lived isotopes in the largest sample at the SLOWPOKE Nuclear Reactor lab, in which they counted the isotopes that were created in the sample while it was in space, exposed to cosmic radiation, but which are now decaying away in the protection of our magnetosphere. Results will be forthcoming in due course.

    For now that largest specimen (151 g) has been returned to Telus World of Science Edmonton where it will ultimately be displayed to the public. It was my pleasure and privilege to have the first opportunity to do so, when I took this specimen along with various other meteorite (and meteorwrong) samples from TWoSE's small collection, to Brentwood School in Sherwood Park the other day. Three classes of Grade 6 students gathered in the music room to hear my presentation on the recent adventures, from fireball to find to analysis. I first took a show of hands and some 22 of 55 students had seen the fireball or its flash, which gave the presentation a here-and-now relevance that is often hard to establish in an astronomy talk. Also relevant to these grade-school science students were images of young scientists like Ellen Milley working in the field and Erin Walton in the lab. The assembled students listened with rapt attention for an hour, passed the specimens around with great interest, treated the newcomer with near reverence, before erupting in a great cheer at the end and proceeding to ply me with dozens of questions. Of the many "sky science" talks I have given over the years I have never encountered a more enthralled or enthusiastic audience. 

    Given the many speaking opportunities that will occur during International Year of Astronomy I anticipate giving more talks that will at least brush on this subject. Talk about a timely gift from the heavens!

    Bruce
    *****