Jenkins-Of-Ewelme Web Site

Position of Planets 2

This page provides a far more comprehensive and scientific view of the of the planetary position calculations. Firstly it assumes an 'epoch of the day' to indicate the Right Ascension (RA) and Declination (DEC) of each object. This is basically the equivalent of Longitude and Latitude on the Celestial Sphere, and is how the position of each star in the sky is defined, but with an epoch of 1st January 2000. RA is defined in Hours, Minutes and Seconds (so never goes above 24 hours, whereas DEC is given in Degrees, Minutes and Seconds having a range of -90 to +90. Depending on the location on the earth and the time, a calculation of the Azimuth and Altitude of a solar system object can be made. Both these values are given in degrees, but some astronomers prefer these to be provided in Deg, Min, Sec format rather than just decimal degrees.