Lunar rocks and regolith returned by the Apollo missions		Meteorites recovered by the U.S. Antarctic Search for Meteorites
	Dust particles collected from the stratosphere		Space-exposed surfaces retrieved from satellites or spacecraft

Maintaining samples in a pure state is critical to extracting scientific information from these unique, and often very small, samples. Equally important, however, is making the collection available for scientific study and education, because it is these activities that give the samples their true value. It is also wise to reserve portions of samples for future studies that will become possible with new or improved ideas and techniques.

Keep the samples pure

Much of the research done on extraterrestrial samples involves measuring very small differences in composition; even tiny amounts of Earth materials can contaminate and ruin scientific measurements. Contamination could be caused by airborne particles getting into the sample or by reaction of the sample with the Earth's atmosphere.

Examples:

The amount of lead in a solder droplet exceeds the amount of lead in all 382 kilograms of lunar samples. It happens that lead resulting from radioactive decay of uranium is one of the indicators used to measure the age of rocks; thus, any Earth-based lead is common in many electrical devices routinely used in laboratories but must be carefully avoided during sample curation.

Moon soil contains pure iron metal, which would quickly rust in Earth's atmosphere, and water-free glass, which reacts with moisture to form clays. Samples must be kept under inert gas.

Our various curatorial laboratories deal with contamination in slightly different ways. Generally, airborne particulate contamination is controlled by air filtration, special clothing on personnel, restricting the types of materials that are used in the laboratory for tools and containers, and scrupulously cleaning the tools and containers that touch the samples. A special team of technicians cleans and certifies tools used in the laboratories. To keep samples from reacting with the Earth's atmosphere, samples are enclosed in gloved cabinets filled with pure nitrogen.




Preserve accurate information about the samples

Great effort is made to document all procedures performed upon samples using written descriptions, photographs and standardized processing procedures. Over the years, a rock may be subdivided into several hundred small pieces, and the orientation or relationship of all the pieces to each other will be recorded in a standard way. The scientific value of a samples is greatly increased when these spatial relationships are known. This is particularly true of space radiation studies where the depth from the surface of the rock is critical.

In addition to purely scientific information, accounting data, such as sample location or weight is also recorded. The curators know where the samples are and how they are being used. Computer data bases are updated daily based on work done in curatorial laboratories and information received from scientific investigators.




Examine and classify samples

Newly obtained samples are examined and classified, so that scientists can use the samples appropriately. For large samples, such as lunar and meteorite samples, examination may consist of observation through the binocular microscope and the preparation of a thin section, from which mineral composition can be identified. For samples too small to see with ordinary means, such as cosmic dust and space-dust impact craters, additional examination may be done with a scanning electron microscope which reveals the particle shape and chemical composition. For some samples, such as the remaining unopened lunar soil cores, the opening, careful dissection and description may take months.




Share information on new samples

Information about new samples is valuable only if it is shared with scientists who need samples for their research. Accordingly, we publish three newsletters (lunar, meteorite, cosmic dust) and one catalog regularly, plus special catalogs as the need arises. Specific information concerning samples can be quickly compiled via computerized databases. Sample information is also shared through presentations at scientific meetings.




Prepare & distribute samples for research and education

Extraterrestrial samples are prepared for shipment in clean room laboratories. Samples are shipped directly to approved scientific researchers. For lunar and meteorite samples, scientific review committees have set aside certain samples for educational use. These samples were prepared into sets with explanatory teaching materials, and are loaned to schools and colleges by the Curator or through the Public Affairs Office.