Analemma over the Callanish Stones captures the Sun’s yearly path

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The Astronomy Picture of the Day (APOD) features an analemma — a composite image showing the Sun’s position photographed from the same location at the same time across the year. For this image, photos were taken every few days at noon near the village of Callanish in the Outer Hebrides of Scotland.

In the foreground of the image are the Callanish Stones, a stone circle constructed around 2700 BC during the Bronze Age. APOD notes that it is not known whether the placement of the Callanish Stones had or has any astronomical significance.

The characteristic figure‑8 of an analemma results from the tilt of Earth’s axis combined with the ellipticity of Earth’s orbit around the Sun. APOD’s explanation specifies that at the solstices the Sun appears at the top or bottom of the analemma, while equinoxes correspond to middle points of the figure rather than its intersection.

The featured composite was taken near the December solstice, which is why the Sun is shown near the lower part of the analemma. The APOD entry also points out that an equinox will occur in two days, when day and night are equal across the planet.

APOD further announces that its main site is moving from apod.nasa.gov to science.nasa.gov/apod. The image credit is given to Giuseppe Petricca; authors and editors listed include Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti and Keighley Rockcliffe. The service is provided by ASD at NASA/GSFC and NASA Science Activation & Michigan Tech. U.

Tomorrow’s picture on APOD is listed as "open space."