Search results
Results from the WOW.Com Content Network
Theoretical astronomy is the use of analytical and computational models based on principles from physics and chemistry to describe and explain astronomical objects and astronomical phenomena. Theorists in astronomy endeavor to create theoretical models and from the results predict observational consequences of those models.
Observational astronomy – practice of observing celestial objects by using telescopes and other astronomical apparatus. It is concerned with recording data. It is concerned with recording data. The subdisciplines of observational astronomy are generally made by the specifications of the detectors, specifically the ranges of wavelengths observed:
In astronomy, Kepler's laws of planetary motion, published by Johannes Kepler in 1609 (except the third law, and was fully published in 1619), describe the orbits of planets around the Sun. These laws replaced circular orbits and epicycles in the heliocentric theory of Nicolaus Copernicus with elliptical orbits and explained how planetary ...
The basic elements of Ptolemaic astronomy, showing a planet on an epicycle (smaller dashed circle), a deferent (larger dashed circle), the eccentric (×) and an equant (•). In both Hipparchian and Ptolemaic systems, the planets are assumed to move in a small circle called an epicycle , which in turn moves along a larger circle called a ...
The horizontal, or altitude-azimuth, system is based on the position of the observer on Earth, which revolves around its own axis once per sidereal day (23 hours, 56 minutes and 4.091 seconds) in relation to the star background. The positioning of a celestial object by the horizontal system varies with time, but is a useful coordinate system ...
French philosopher and mathematician René Descartes was the first to propose a model for the origin of the Solar System in his book The World, written from 1629 to 1633.. In his view, the universe was filled with vortices of swirling particles, and both the Sun and planets had condensed from a large vortex that had contracted, which he thought could explain the circular motion of the plane
The holiday season in December is often labeled as "the most wonderful time of the year," but for outdoor enthusiasts and folks who love to soak in the sun, that title belongs to the summer months.
This article is a list of notable unsolved problems in astronomy. Problems may be theoretical or experimental. Theoretical problems result from inability of current theories to explain observed phenomena or experimental results. Experimental problems result from inability to test or investigate a proposed theory.