Science paper: The Sutter's Mill Meteorite

Sat, 12/22/2012 - 14:00 -- pheck

A composite RGB x-ray map of the elements magnesium (red), calcium (green), aluminum (blue). This map was made by the Chicago team of the Sutter's Mill consortium and helps to determine the mineralogy of the meteorite.

Robert A. Pritzker Assistant Curator of Meteoritics and Polar Studies Dr. Philipp R. Heck is co-author on a paper in the journal Science on the first results of the rare meteorite, Sutter’s Mill. On April 22 a very fast-moving fireball was observed over large parts of California and Nevada. Equivalent to four kilotons of TNT, the fireball was photographed, and recorded by video and by weather Doppler-radars. The photographs and videos helped to trace back its orbit to the far reaches of the outer part of the asteroid belt. The Sutter’s Mill meteorite was scrutinized by almost the entire arsenal of observational and analytical state-of-the-art tools available to scientists today. The impressive synthesis of the collective results is published in this week’s edition of Science.

Philipp and his colleagues studied a piece of the meteorite that was donated to The Field Museum by meteorite collector, philanthropist and C&R Committee member Terry Boudreaux. Philipp prepared a polished section of the meteorite, and then he, University of Chicago Professor and Field Museum Research Associate Dr. Andrew M. Davis (Geology/University of Chicago), and senior scientist Dr. Stephen B. Simon studied it with a scanning electron microscope to prepare a petrographic description and produce high-quality X-ray maps to determine its chemical and mineralogical composition (see image). Sutter’s Mill meteorite is a so-called carbonaceous chondrite which is much more diverse in its composition than other meteorites of this type. The unique rock came from a dark, carbon-rich asteroid that experienced an unexpectedly large variety of geological processes on its surface. The reflectance spectrum of the Sutter’s Mill meteorite suggests it is similar to the asteroid that will be visited by the Japanese space mission Hayabusa-2 in 2018. Thus, this meteorite seems to be the ideal sample to prepare cosmochemists for the arrival of Hayabusa-2.

Philipp says, “I am fortunate to study this interesting, rare and unique meteorite, and will also preserve pristine pieces of it at The Field Museum for future generations of scientists who will be armed with analytical tools of which we can only dream of today.” Read the abstract here.