Positional astronomy is the study of the positions of celestial objects. This is the oldest branch of astronomy and dates back to antiquity. Observations of celestial objects are important for religious and astrological purposes, as well as for timekeeping. In ancient Greece and other early civilizations, astronomy consisted largely of astrometry, measuring positions of stars and planets in the sky. ... This article needs to be cleaned up to conform to a higher standard of quality. ... An astrological chart (or horoscope) - Y2K Chart — This particular chart is calculated for January 1, 2000 at 12:01:00 A.M. Eastern Standard Time in New York City, New York, USA. (Longitude: 074W0023 - Latitude: 40N4251), using the tropical zodiac Astrology (from Greek: αστρολογία = άστρον, astron, star + λόγος, logos, word) is... For alternate uses of time, see Time (disambiguation) or see TIME (magazine). ...

The science of actually measuring positions of celestial objects in the sky is known as astrometry. Astrometry is a part of Astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ...

Ancient structures associated with positional astronomy include:

• Chichen Itza
• The Medicine Wheel
• The Pyramids
• Stonehenge
• The Temple of the Sun

The unaided human eye can detect about 6000 stars, of which about half are below the horizon at any one time. Temple of the Warriors Chichen Itza is the largest of the Pre-Columbian archaeological sites in Yucat n, Mexico. ... A medicine wheel at Big Horn Medicine wheels are stone structures built by the natives of America and Canada for various spiritual and ritual purposes. ... Geometric shape created by connecting a polygonal base to an apex A pyramid is a geometric shape formed by connecting a polygonal base and a point, called the apex, by triangular faces. ... Stonehenge Stonehenge is a Neolithic and Bronze Age monument located near Amesbury in the English county of Wiltshire, about 8 miles (13 km) northwest of Salisbury. ... Prisoners of the Sun (originally Le Temple du Soleil) is one of a series of classic comic-strip albums, written and illustrated by Belgian writer and illustrator Hergé, featuring young reporter Tintin as a hero. ... The Pleiades star cluster A star is any massive gaseous body in outer space, just like the Sun. ...

On modern star charts, the celestial sphere is divided into 88 constellations. Every star lies within a constellation. In astronomy and navigation, the celestial sphere is an imaginary rotating sphere of gigantic radius, concentric with the Earth. ... Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ...

Constellations are useful for navigation. If you live in the northern hemisphere you can find north by locating the star Polaris. This star is always at a position nearly over the north pole. There are several traditions of navigation. ... Polaris or Cynosura (α UMi / α Ursae Minoris / Alpha Ursae Minoris) is the brightest star in the constellation Ursa Minor. ... A North Pole is the northernmost point on any planet. ...

See also:

• Planets which are in conjunction form a line which passes through the center of the solar system
• The ecliptic is the plane which contains the orbit of a planet, usually in reference to Earth
• Elongation refers to the angle formed by a planet, with respect to the system's center and a viewing point
• Superior planets have a larger orbit than the earth while the inferior planets (Mercury and Venus) orbit the sun inside the earth's orbit
• A transit occurs when an inferior planet passes through a point of conjunction

Mosaic of Solar System planets except Pluto, including Earths Moon (not to scale). ... The plane of the Ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft. ... In mathematics, a plane is the fundamental two-dimensional object. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ... This diagram shows the elongations (or angle) of the Earths position from the Sun. ... This article is about angles in geometry. ... The word point can refer to: a location in physical space a unit of angular measurement; see navigation point is a typographic unit of measure in typography equal inch or sometimes approximated as inch; on computer displays it should be equal to point in typography if the correct display resolution... The terms inferior planet and superior planet were coined by Copernicus to distinguish a planets orbits size in relation to the Earths. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... The terms inferior planet and superior planet were coined by Copernicus to distinguish a planets orbits size in relation to the Earths. ... Deimos transits the Sun, as seen by Mars Rover Opportunity on March 4, 2004 The word transit has two meanings in astronomy: A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, as seen by an observer at...

See also

• angle
• diurnal motion
• eclipse
• ecliptic
• elongation
• epoch
• equinox
• Halley, Edmund
• History of Astronomy
• Kepler's laws of planetary motion
• prograde and retrograde motion
• Moon
• occultation
• parallax
• sidereal time
• solstice
• time
• astrology
• jyotish
• Chinese astrology