> Niobium and hafnium do not occur as free elements in nature, but are refined from mineral ores. They are used in semiconductors and superalloys.
> In addition to these two unusual elements, a significant number of particles contained copper, lithium and aluminum at concentrations far exceeding the abundance found in meteorics, or ‘space dust.’ “The combination of aluminum and copper, plus niobium and hafnium, which are used in heat-resistant, high-performance alloys, pointed us to the aerospace industry,’’ Murphy said.
