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astronomy terms library
Astronomy terms are used to describe the various phenomena in space. In this section you can learn what every astronomy term means and how it helps us to better understand the cosmos.
Night
Night, the period of darkness caused by the disappearance of the sun below the horizon.
See more »Nova
Nova, (plural: Novae), a star that rapidly increases in brightness and then fades again.
See more »Occultation
Occultation, in astronomy, the passing of the moon or some other object of the solar system in front of a planet, star, or other celestial body, hiding it from view.
See more »Orbit
Orbit, the path of a celestial body or other object in space, governed by the gravitational attraction of other bodies.
See more »Orrery
Orrery, a mechanical device used to show the motions of bodies within the solar system.
See more »Parallax
Parallax, the apparent change in position of an object when it is viewed from two different locations.
See more »Perihelion and Aphelion
Perihelion and Aphelion, The perihelion is the point on the orbit of a planet or comet that is closest to the sun.
See more »Perturbation
Perturbation, in astronomy, a disturbance in the orbit or motion of a heavenly body.
See more »Planetarium
Planetarium, is an educational device for showing the locations and movements of the planets and other objects in the universe.
See more »Planetesimal Hypothesis
Planetesimal Hypothesis, a theory of the origin of the solar system. It was proposed by Forrest R.
See more »Pulsar
Pulsar, a celestial body that emits radio signals in short, very evenly spaced bursts, or pulses.
See more »Quasar
Quasar, or Quasi-stellar Object (QSO), a starlike object displaying an unusually large red shift.
See more »Satellite, Artificial
Satellite, Artificial, a man-made object that orbits the earth, the moon, the sun, or any other celestial body.
See more »Seasons
Seasons, the four divisions of the year, called spring, summer, autumn (or fall), and winter.
See more »Sextant
Sextant, a navigation instrument used to measure angles, particularly the altitudes of the sun and stars above the horizon.
See more »Solar Wind
Solar Wind, a continuous stream of matter that flows outward from the sun in all directions.
See more »Solstice
Solstice,. During the course of a year, the sun appears to move northward for about six months and southward for about six months.
See more »Summer
Summer, the season of the year occurring between spring and autumn. Astronomically, summer in the Northern Hemisphere lasts from about June 21 to September 23; in the Southern Hemisphere, from about December 22 to March 21.
See more »Sundial
Sundial, a device used to tell time by the sun. Nearly every sundial has two basic parts: a pointer, called a style or gnomon, which casts a shadow; and a numbered dial on which the shadow falls to show the hour.
See more »Transit
Transit, in astronomy, the passage of one celestial body across the disc (face) of a larger, more distant body, or across the observer's meridian.
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