There may be itsy-bitsy aliens among us.
Scientists say seven microscopic particles collected by NASA's comet-chasing spacecraft, Stardust, appear to have originated outside our solar system. If confirmed, this would be the world's first sampling of contemporary interstellar dust.
The dust collectors were exposed to space in the early 2000s and returned to Earth in 2006. Since then, dozens of scientists worldwide led by physicist Andrew Westphal, of the University of California, Berkeley, have hunted for specks and analyzed the "precious" grains found.
The team was assisted by 30,000 citizen-scientists, who scanned more than 1 million images in search of elusive tracks made by incoming particles.
Westphal says the suspected interstellar particles are surprisingly diverse. Some are fluffy like snowflakes.
The findings were published Thursday in the journal Science.