Accurate analytic representations of solar time and seasons on Mars with applications to the Pathfinder/Surveyor missions

Efficient analytic recipes are presented for a moderately accurate, closed‐form calculation of the areocentric longitude (Ls), analemmic “equation of time,” and solar hour angles on Mars, along with an approximate recovery of the Viking “Local Lander Time.” The adopted fit to the fictitious mean sun implies a Mars tropical orbit period of 686.9725 d .