github.com/exploded/sun (go): Package sun returns the altitude of the Sun for any time and location.  Location is supplied as decimal longitude and latitude of the observer.  This package could be useful for estimating the sky brightness around sunrise/sunset.  Refer to https://en.wikipedia.org/wiki/Position_of_the_Sun#Declination_of_the_Sun_as_seen_from_Earth  Steps:  1. Calculate the ecliptic coordinates of the sun  2. Calculate equatorial coordinates  3. Convert easily to horizontal coordinates  4. From which we get the ALTITUDE of the sun as desired  CREDITS:  Major portion from https://github.com/giraj/sun-altitude.js/  Licence : none  Some jde and utility portions based on https://github.com/soniakeys/meeus  License MIT: http://www.opensource.org/licenses/MIT
Keywords: astronomy