- Industry: Aerospace
- Number of terms: 16933
- Number of blossaries: 2
- Company Profile:
The Executive Branch agency of the United States government, responsible for the nation's civilian space program and aeronautics and aerospace research.
An ideal or imaginary body that is absolutely black when cold, but is a perfect absorber of radiation and at the same time a perfect radiator. Black body temperatures are used to work out the theoretical laws of radiation and to calculate the temperature of the sun.
Industry:Astronomy
The emission of electromagnetic radiation as the result of exposure to some other radiation, which emission ceases when the stimulus that produces it ceases to act on the emitting substance. Thus light passing through a gas, may change the energy state of the atoms and cause them to emit light of a different wavelength.
Industry:Astronomy
The alternate light and dark bands that are seen when two beams of homogenous light enter into interference with each other, i. E. , when they overlap and illuminate an identical area.
Industry:Astronomy
Any instrument designed for producing and studying interference of two or more trains of waves or beams of electromagnetic radiation of the same range of wavelengths. Usually denotes an optical interferometer that separates a beam of light into two or more parts that travel in different paths and are then combined together to produce interference fringes.
Industry:Astronomy
The s. I. Unit of energy, work, or quantity of heat. It is the force of one newton acting over a distance of a meter.
Industry:Astronomy
Laws governing the motions of planets in their orbits:. # the orbits of the planets are ellipses with the sun at a common focus. # the line joining a planet and the sun sweeps over equal areas during equal intervals of time. # the squares of the periods of revolution of any two planets are proportional to the cubes of their mean distances from the sun.
Industry:Astronomy
A "secondary rocket" intended to be used for descending to the surface of the moon or another planet while the major vehicle remains in an orbit around the destination body.
Industry:Astronomy
The amount of matter in a body, which should not be confused with weight. The same object will have different weights in space and earth but the mass remains constant.
Industry:Astronomy
The point on the celestial sphere that is diametrically opposite the zenith, so that the zenith, nadir and center of earth are in one straight line. It is always 90 degrees below the horizon.
Industry:Astronomy
The hiding of one heavenly body by another, as when the moon passes between earth and a star, or when one of the moons of jupiter or saturn passes behind the planet.
Industry:Astronomy
