Free Republic 3rd Quarter Fundraising Target: $85,000 Receipts & Pledges to-date: $26,735
31%  
Woo hoo!! And the first 31% is in!! Thank you all very much!!

Keyword: pierrehaenecour

Brevity: Headers | « Text »
  • Supernova Dust Fell to Earth in Antarctic Meteorites

    04/28/2013 10:19:12 AM PDT · by SunkenCiv · 17 replies
    Scientific American 'blogs ^ | April 24, 2013 | John Matson
    In the new study (pdf), Pierre Haenecour of Washington University in St. Louis and his colleagues analyzed two meteorites collected in Antarctica in 2003, each named for a geographic feature near the spot where the meteorite fell. (Antarctica makes an ideal hunting ground for dark-colored meteorites, which stand out clearly against the ice fields.) Grove Mountains 021710, found by a Chinese expedition, and LaPaz Icefield 031117, collected by U.S. searchers, each harbor presolar grains of silica (SiO2), the researchers found, as evidenced by the grains’ enrichment in a heavy isotope of oxygen known as oxygen 18. That signature points to...