Surprise found in comet dust

Odd mineral offers clues to solar system's origins

Researchers have found a new mineral within an interplanetary dust particle. The substance — a manganese silicide named Brownleeite — appears to have come from comet 26P/Grigg-Skjellerup, NASA announced June 12.

Originally seen in 1902, the comet reappears every five years.

In 2002, NASA space scientist Scott Messenger predicted that as they pass, comets shed dust grains that fall into Earth’s upper atmosphere.