They weigh just 10 trillionths of a gram, but could help astronomers unlock the mysteries of a different galaxy.
Researchers have been studying tiny specks of dust captured by NASA's Stardust spacecraft, believed to be the first material from outside our solar system ever brought back to Earth. These incredibly fragile pieces were caught in Stardust's collection panels during a seven year, 3 billion mile trip that ended in 2006. The cosmic dust was traveling at 20,000 mph when trapped by the Stardust, which according to one astronomer, was "like trying to stop bullets with cotton candy."
The goal of the Stardust's mission was twofold: collect particles from the comet Wild-2’s tail end, and accumulate interstellar dust. Only two pieces of dust survived largely intact, and astronomers so far have been stunned by the diversity of the particles.
"We're all made out of recycled dust — and we're just inherently interested in knowing what the dust we came from was like," Rhonda Stroud, a nanoastronomer at the Naval Research Laboratory in Washington and coauthor of a study on the dust, told the Los Angeles Times. "And this contemporary interstellar dust is giving us an idea of what new solar systems will be made of."