How were the interstellar dust particles captured?
A. The spacecraft Stardust was equipped with a tennis-racquet shaped particle collector made of aerogel plates. In two different periods during Stardust’s 7-year journey in space — between February and May of 2000 and August and December of 2002 — the spacecraft passed through the interstellar-dust particle stream that flows through our solar system. During those periods, Stardust extended its particle collector so that the aerogel was exposed to the particle stream. The interstellar dust grains struck the aerogel at high speeds of up to 26 kilometers per second (16 miles per second) and embedded themselves within this ultralight material. The particles will remain stored within the aerogel until they are extracted by scientists for study.
