Nanometer-scale anatomy of entire Stardust tracks

作者：Nakamura Messenger Keiko^*; Keller Lindsay P; Clemett Simon J; Messenger Scott; Ito Motoo

来源：Meteoritics & Planetary Science, 2011, 46(7): 1033-1051.

DOI：10.1111/j.1945-5100.2011.01211.x

We have developed new sample preparation and analytical techniques tailored for entire aerogel tracks of Wild 2 sample analyses both on "carrot'' and "bulbous'' tracks. We have successfully ultramicrotomed an entire track along its axis while preserving its original shape. This innovation allowed us to examine the distribution of fragments along the entire track from the entrance hole all the way to the terminal particle. The crystalline silicates we measured have Mg-rich compositions and O isotopic compositions in the range of meteoritic materials, implying that they originated in the inner solar system. The terminal particle of the carrot track is a (16)O-rich forsteritic grain that may have formed in a similar environment as Ca-, Al-rich inclusions and amoeboid olivine aggregates in primitive carbonaceous chondrites. The track also contains submicron-sized diamond grains likely formed in the solar system. Complex aromatic hydrocarbons distributed along aerogel tracks and in terminal particles. These organics are likely cometary but affected by shock heating.

• 出版日期2011-7