Astronomy

Astronomy Images

(To View New Images Just Refresh The Page)

Astronomy Definitions and Factiods

Astronomy Definitions 2

Ion Microprobe: A Secondary Ion Mass Spectrometer (SIMS), a precision instrument used to quantitatively analyze the elements and isotopes of materials at microscopic scales.

Iron: An element with atomic number 26; sumbol: Fe. Iron is one of the most abundant elements in the rocky planets. It is the most abundant element in the metallic cores of the inner planets.

Iron Meteorite: Iron meteorites are made, almost completely, of nickel-iron metal. They are chemically distinguished and grouped according to the abundances of the trace elements such as gallium and germanium, as well as nickel. Initially, irons were classified into four groups and were given Roman numerals I, II, III, and IV. Today twelve groups are recognized and designated further by letters A through F. Iron meteorites that do not fit into the groups are called ungrouped.

Isotopes: Two or more varieties of the same chemical element. Isotopes have different masses because they have different numbers of neutrons (for example 18O and 16O), thus they have different physical and chemical properties. Unstable isotopes undergo radioactive decay.