Brownleeite is a

silicide A silicide is a type of chemical compound that combines silicon and a usually more electropositive element. Silicon is more electropositive than carbon. In terms of their physical properties, silicides are structurally closer to borides than t ...

mineral with

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

MnSi Manganese monosilicide (MnSi) is an intermetallic compound, a silicide of manganese. It occurs in cosmic dust as the mineral brownleeite. MnSi has a cubic crystal lattice with no inversion center; therefore its crystal structure is helical, wit ...

. It was discovered by researchers of the

Johnson Space Center The Lyndon B. Johnson Space Center (JSC) is NASA's center for human spaceflight in Houston, Texas (originally named the Manned Spacecraft Center), where human spaceflight training, research, and flight controller, flight control are conducted. ...

Houston Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...

while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is

mavlyanovite Mavlyanovite is a rare manganese-silicon mineral with formula Mn5Si3. It was named after Gani Mavlyanov, an Uzbek geologist who lived from 1910 to 1988. The mineral was first found in lamproite, as a phase that had crystallised from volcanic gla ...

, Mn₅Si₃.

Overview

The particles were collected from the

stratosphere The stratosphere () is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher ...

over south-western US in April 2003 using an ER-2 high-altitude research aircraft of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

. The team of researchers from US, Germany and Japan was led by NASA scientist Keiko Nakamura-Messenger. To determine the mineral's origin and examine other dust materials, a new transmission electron microscope was installed in 2005 at Johnson Space Center. The mineral name was approved by the

International Mineralogical Association Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. ...

(IMA Number 2008-011). The NASA scientists named the mineral after

Donald E. Brownlee Donald Eugene Brownlee (born December 21, 1943) is a professor of astronomy at the University of Washington at Seattle and the principal investigator for NASA's Stardust (spacecraft), Stardust mission. In 2000, along with his co-author Peter Ward ...

, professor of astronomy at the

University of Washington The University of Washington (UW and informally U-Dub or U Dub) is a public research university in Seattle, Washington, United States. Founded in 1861, the University of Washington is one of the oldest universities on the West Coast of the Uni ...

, Seattle, because of his pioneering research on interplanetary dust particles.Universe Today June 12, 2008: Alien Mineral From Comet Dust Found in Earth's Atmosphere
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References

External links

* {{Manganese minerals Manganese(IV) minerals Native element minerals Cubic minerals Minerals in space group 198 Minerals described in 2010

Overview

See also

References

External links