15 February 2010

An analemma is the curious figure-of-eight pattern (or lemniscate) made in the sky if you trace the sun’s position at mid-day (or any other time) over its annual cycle.  The difference in the sun’s position is caused by the tilt of planet Earth’s axis and its variation in speed as it moves around its orbit.  In any analemma, the solstices are represented by the lowest and highest points on the curve (with the lowest or southernmost being the winter solstice); and the equinoxes (days of equal night and day) by the place in the middle where the sun’s path crosses itself.

This photographic analemma taken over the course of a year in Side, Turkey, includes one special solar image: the corona from the total solar eclipse on 29 March 2006.  The planet Venus was also visible during totality in the lower right of the picture.

Notice also how the infinity curves of the helter-skelter on the ground echo the helter-skelter infinity of the night sky.

picture of Analemma taken in Side, Turkey in 2005-06