- 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 ...
Angle between the plane of the object's orbit and the ecliptic (defined by Earth's orbit).
Industry:Astronomy
An element with atomic number 7; symbol: N. It is common in Earth's atmosphere and along with hydrogen, carbon, and oxygen is essential for life.
Industry:Astronomy
Astronomical brightness measured on a logarithmic scale, based on the ancient practice of noting that the brightest stars in the sky were of "first importance" or "first magnitude", the next brightest being "second magnitude" etc. The human eye is a logarithmic detector, and in 1854 Pogson formalized this scale and defined a difference of 5 magnitudes to be exactly a factor of 100 in brightness. The scale is calibrated to the bright star Vega which is defined to have a magnitude of 0. For reference, the faintest naked-eye magnitude visible from a dark site is +6. Comet C/1996 B2 Hyakutake reached magnitude 0 in late March 1996.
Industry:Astronomy
The central region of a planet or moon frequently made of denser materials than the surrounding regions (mantle and crust). Earth and the Moon are thought to have cores of iron and nickel.
Industry:Astronomy
Term applied to molten rock in the interior of a planet or moon. When it reaches the surface, magma is called lava.
Industry:Astronomy
Elements that are not incorporated into common rock-forming minerals during magma crystallization, hence they become enriched in the residual magma and in the rocks finally formed from it. Examples are: potassium, rubidium, strontium, hafnium, thorium, uranium, and lanthanum, samarium, europium, and the rest of the rare earth elements (REE).
Industry:Astronomy
The region of space between the orbits of Mars and Jupiter, from 2. 1 to 3. 3 AU, where most asteroids are found.
Industry:Astronomy
