miércoles, 6 de abril de 2011

NASA Researchers Find Brand New Mineral in Old Meteorite


NASA Researchers Find Brand New Mineral in Old Meteorite


A bright field scanning transmission electron microscope (STEM) micrograph showing a Wassonite grain in dark contrast. Credit: NASA
It’s a brand new mineral, and it’s from space. Researchers taking a new look at an old meteorite with a high-tech electron microscope have found a new mineral, now called Wassonite, in a space rock found in Anarctica back in 1969, the Yamato 691 enstatite chondrite. The meteorite likely originated from the Asteroid Belt between Mars and Jupiter and is about 4.5 billion years old.
“Wassonite is a mineral formed from only two elements, sulfur and titanium, yet it possesses a unique crystal structure that has not been previously observed in nature,” said Keiko Nakamura-Messenger, a NASA scientist who headed the research team.
Wassonite now joins the list of 4,500 official minerals, approved by the International Mineralogical Association. It was named after meteorite researcher John T. Wasson, from the University of California, Los Angeles (UCLA).
But there could be more unknown minerals inside the meteorite. The researchers found Wassonite surrounded by additional minerals that have not been seen before, and the team is continuing their investigations.
The amount of Wassonite in the rock is less than one-hundredth the width of a human hair or 50×450 nanometers wide. Without NASA’s transmission electron microscope, which is capable of isolating the Wassonite grains and determining their chemical composition and atomic structure, the mineral would have been impossible to see.
In 1969, members of the Japanese Antarctic Research Expedition discovered nine meteorites on the blue ice field of the Yamato Mountains in Antarctica. This was the first significant recovery of Antarctic meteorites and represented samples of several different types. As a result, the United States and Japan conducted systematic follow-up searches for meteorites in Antarctica that recovered more than 40,000 specimens, including extremely rare Martian and lunar meteorites.
“More secrets of the universe can be revealed from these specimens using 21st century nano-technology,” said Nakamura-Messenger.
“Meteorites, and the minerals within them, are windows to the formation of our solar system,” said Lindsay Keller, space scientist at NASA’s Johnson Space Center in Houston, who was the principal investigator of the microscope used to analyze the Wassonite crystals. “Through these kinds of studies we can learn about the conditions that existed and the processes that were occurring then.”
For more information see this NASA pdf. which provides more images and details about the Wassonite detection.