- 行业: Astronomy
- Number of terms: 6727
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Planetary Science Research Discoveries (PSRD) is an educational site sharing the latest research by NASA-sponsored scientists on meteorites, asteroids, planets, moons, and other materials in our Solar System. The website is supported by the Cosmochemistry Program of NASA's Science Mission ...
Location where igneous matter (lava and gases) erupts onto the surface; vent, fissure, volcano, etc.
Industry:Astronomy
Iron meteorites are made, almost completely, of iron and nickel 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 according to concentrations of siderophile ("iron-loving") trace elements. Iron meteorites that do not fit into the groups are called ungrouped. The two iron-nickel alloys in iron meteorites are called kamacite (low-nickel content, usually up to 7. 5 wt% nickel) and taenite (high-nickel content, ~20 to 50 wt% nickel). These alloys are rare in terrestrial rocks. (See also Widmanstätten Pattern. )
Industry:Astronomy
U. S. Discovery-class mission to the Moon launched on January 6, 1998. Its instruments were designed to provide global maps and data sets of the Moon's composition and magnetic and gravity fields from a low polar orbit. The mission lasted 18 months and ended July 31, 1999 with a controlled crash landing into a crater at the Moon's south pole.
Industry:Astronomy
Invisible part of the light spectrum where wavelengths are shorter than the visible spectrum and longer than X rays.
Industry:Astronomy
The portion of Earth, or other planet, that is water, including liquid water, ice, and water vapor on the surface, underground, or in the atmosphere.
Industry:Astronomy
An element that concentrates in iron or that forms alloys easily with iron. Siderophile means "iron loving. "
Industry:Astronomy
MgAl<sub>2</sub>O<sub>4</sub>, magnesium aluminum oxide mineral, with Cr able to substitute for Al.
Industry:Astronomy
Explosive eruption of lava producing and ejecting hot fragments of rock and lava.
Industry:Astronomy
A precision measurement technique used to quantitatively analyze the elements and isotopes of materials at microscopic scales (with a typical spatial resolution of 1 micrometer). A SIMS instrument is also called an ion microprobe.
Industry:Astronomy
A temperature scale that assigns the value 0° C to the freezing point of water and the value of 100° C to the boiling point of water at standard pressure. To convert Celsius to Fahrenheit: Multiply by 9, then divide by 5, then add 32.
Industry:Astronomy
