Silicate minerals that predate the Solar System have been detected inside primitive stony meteorites. Isotopic analysis suggests that the silicates probably condensed around dying ancient stars. Meteorites that date from around the time of the formation of the Solar System ― a little over four and a half billion years ago ― are testament to the events that occurred before and during planet formation. Most of the interstellar dust that went into forming planetary precursors was melted, vaporized, shocked and, once incorporated into asteroids, further heated and damaged. This has caused the chemistry and isotopic composition of minerals from meteorites to become more homogeneous. But a few mineral survivors predate these events. These presolar grains originated around stars that were the predecessors of our own, and made up part of the interstellar medium before collapsing into our Solar System. Several carbonaceous and oxide presolar grains have been identified in meteorite samples. Nagashima et al. 1 have now uncovered presolar specimens of silicates, the most common rock-forming minerals (page 921 of this issue).
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