| | In July of 2004, the Stardust mission approached to within 150 miles of Comet Wild 2 and was able to sample its tail and return the samples to earth (January 2006). The returned dust was crystalline and included organic material, water ice, and many terrestrial minerals. These included [[aluminum]], [[magnesium]], [[calcium]], and [[titanium]].<ref name=Brown/> | | In July of 2004, the Stardust mission approached to within 150 miles of Comet Wild 2 and was able to sample its tail and return the samples to earth (January 2006). The returned dust was crystalline and included organic material, water ice, and many terrestrial minerals. These included [[aluminum]], [[magnesium]], [[calcium]], and [[titanium]].<ref name=Brown/> |
| − | One year later, on July 4, 2005, the [[Deep Impact mission]] conducted the first direct analysis of the rocky portion of a comet nucleus, by launching a projectile into Comet Tempel 1. The projectile liberated much material, including silicates, crystalline silicates, minerals that normally form in liquid water ([[calcium carbonate]] forms and clays), an organic material of still undetermined composition, sodium, and a very fine powder.<ref name=Brown/> | + | One year later, on July 4, 2005, the Deep Impact mission conducted the first direct analysis of the rocky portion of a comet nucleus, by launching a projectile into Comet Tempel 1. The projectile liberated much material, including silicates, crystalline silicates, minerals that normally form in liquid water ([[calcium carbonate]] forms and clays), an organic material of still undetermined composition, sodium, and a very fine powder.<ref name=Brown/> |