NASA researchers and scientists from the United States, Germany and Japan have found a new mineral in material they believe came from a comet. The mineral, a manganese silicide named Brownleeite, was discovered within an interplanetary dust particle, or IDP, that appears to have originated from comet 26P/Grigg- Skjellerup. The comet originally was discovered in 1902 and reappears every 5 years.
Scott Messenger, a space scientist at Johnson Space Center in Houston, predicted comet 26P/Grigg-Skjellerup was a source of dust grains that could be captured in Earth's stratosphere at a specific time of the year. In response to his prediction, NASA performed stratospheric dust collections using an ER-2 high-altitude aircraft flown from NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. The aircraft collected IDPs from this particular comet stream in April 2003. The new mineral was found in one of those particles.
To determine the mineral's origin and examine other dust materials, a powerful new transmission electron microscope was installed in 2005 at Johnson. The mineral was surrounded by multiple layers of other minerals that also have been reported only in extraterrestrial rocks. There have been 4,324 minerals identified by the International Mineralogical Association. This find adds one more to that list.