Keplerian Elements

###for Approximate Positions of the Major Planets

"Lower accuracy formulae for planetary positions have a number of important applications when one doesn't need the full accuracy of an integrated ephemeris. They are often used in observation scheduling, telescope pointing, and prediction of certain phenomena as well as in the planning and design of spacecraft missions."

positions valid for 1800 AD - 2050 AD

double[] calculateLocationOfPlanet(int planet, float time)

returns an array double, double, double for X, Y, Z position in the J2000 ecliptic plane with the equinox aligned to the X axis.

int planet 0=Mercury 1=Venus 2=Earth/Moon Barycenter… 7=Neptune

float time in centuries after the year 2000.

###Mouse

• scroll to zoom
• click to switch between slow/fast

NASA JPL (sec 8.10): http://iau-comm4.jpl.nasa.gov/XSChap8.pdf

http://ssd.jpl.nasa.gov/?planet_pos information on margin of error