Origin of some cosmic dust is discovered

LONDON, Sept. 3 (UPI) -- An Imperial College London scientist says he's discovered some of the microscopic meteorites making up "cosmic dust" originate from an ancient asteroid belt.

Matthew Genge of the college's Department of Earth Science and Engineering said his research shows some of the cosmic dust falling to Earth comes from an asteroid belt between Jupiter and Mars.

The researchers said cosmic dust particles, originally from asteroids and comets, are tiny pieces of pulverized rock measuring up to 0.1 millimeter in size. They said studying cosmic dust is important since the mineral content reveals the conditions that existed more than 4.5 billion years ago.

Scientists previously thought analyzing individual dust particles was the key to tracing their origin, but Genge said a comparison of multiple particles gives better results.

"It was only when I took a step back and looked at the minerals and properties of hundreds of particles that it was obvious where they came from," he said. "It was like turning over the envelope and finding the return address on the back."

The research is reported in the journal Geology.