- 産業: Astronomy
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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 ...
Streams of plasma--charged particles (mainly ionized hydrogen and some helium but actually a mixture of all electrons and protons in the Sun)-- ejected from the outer atmosphere (corona) of the Sun and moving outward all the time with velocities in the range 300-500 kilometers per second. For amazing images and information about the Sun and solar wind see the SOHO website for the Solar and Heliospheric Observatory, a project of international cooperation between ESA and NASA.
Industry:Astronomy
An element with atomic number 16; symbol: S. Sulfur is common on the surface of Jupiter's moon Io.
Industry:Astronomy
An element with atomic number 12; symbol: Mg. Magnesium is contained in the minerals olivine and pyroxene, and is very abundant in the mantles of the inner planets.
Industry:Astronomy
The study of spectra. Every atom can only emit or absorb certain energies or wavelengths. Scientists use instruments called spectrometers to study the location and spacing of reflectance, emission, and absorption (spectral) lines in specific wavelengths to detect any atoms or molecules that may be present in a target material (such as minerals on the surface of the Moon or a planet).
Industry:Astronomy
The standard unit of pressure is the pascal, abbreviated Pa, which is equivalent to 1 kg/m<sup>2</sup>. The pressure at the surface of the Earth is 100,000 Pa. Pressures inside planets are very large numbers, usually expressed as GPa (giga means billion).
Industry:Astronomy
The forceful striking of one body, such as a meteorite, against another body such as a moon or planet.
Industry:Astronomy
Two or more varieties of the same chemical element. Isotopes have different masses because they have different numbers of neutrons (for example <sup>18</sup>O and <sup>16</sup>O), thus they have different physical and chemical properties. Unstable isotopes undergo radioactive decay.
Industry:Astronomy
Mountain formed from the eruption of igneous matter through a source vent.
Industry:Astronomy
