Stardust Delivers First Solid Comet Dust to Earth, Revealing a Complex Solar System Recipe
NASA’s Stardust flew through comet 81P/Wild 2’s coma in 2004, catching dust in a silica aerogel and returning to Utah in 2006 after a 4.63 billion-kilometre journey—the first solid cometary material brought to Earth. The samples, more than 10,000 grains, showed a mix of materials formed in hot and cold regions of the early Solar System, including crystalline silicates and a calcium-aluminium-rich inclusion; in 2009 glycine, a simple amino acid, was identified, demonstrating that comets carry prebiotic molecules and that returning samples allows reanalysis with advancing techniques.