Physics Department Colloquia
Please join us for this exciting talk, and enjoy some refreshments.
Monday February 6th , 4:00 P.M. in Daly Science 206
Meteorite Physical Property Measurements: Down-to-Earth Planetary Science
Br. Robert J. Macke, S.J., Ph.D. Current Affiliation: Boston College
Meteorites are scientifically valuable because they originate from disparate solar system bodies and have through their own accord made it to earth – they need only be collected and studied. Most such studies have focused on detailed chemical and isotopic analyses for small samples (thin sections or ~300 mg portions), but the measurement of whole-rock physical properties (i.e. density, porosity, magnetic susceptibility) supplements these studies and utilizes samples massing in the tens of grams. Data from such studies can, among other things, constrain models of parent-body formation.
With the advent of fast, non-destructive and non-contaminating measurement techniques including helium ideal-gas pycnometry for grain density, the Archimedean "glass-bead" method for bulk density and (with grain density) porosity, and the use of low-field magnetometry for magnetic susceptibility, all of which rely on compact and portable equipment, this has enabled a comprehensive survey of these physical properties for a wide variety of meteorites. This survey to date has spanned seven major museum and university meteorite collections as well as the Vatican collection. I will discuss these measurement techniques and several of the more interesting findings. The talk will conclude with a short discussion of current ongoing research, including the application of these techniques to the measurement of lunar and martian meteorites as well as Apollo lunar samples.
