This amazing image follows the sun's path every day over...

This amazing image follows the sun's path every day over the course of a half-year, from June 21 to December 21. Each upside down "V" is a trace of the sun as it travels from sunrise to sunset. On June 21, the Summer Solstice, the longest day of the year, that upside-down "V" is the highest solar arc in the picture. Every successive day after that is slightly lower than the one before it. Till you get to the shortest day of the year, Dec. 21. 

Here is the photographer's description. (From NASA's "Astronomy photograph of the day")

From solstice to solstice, this six month long exposure compresses time from the 21st of June till the 21st of December, 2011, into a single point of view. Dubbed a solargraph, the unconventional picture was recorded with a pinhole camera made from a drink can lined with a piece of photographic paper. Fixed to a single spot for the entire exposure, the simple camera continuously records the Sun's path each day as a glowing trail burned into the photosensitive paper. In this case, the spot was chosen to look out over the domes and radio telescope of the University of Hertfordshire's Bayfordbury Observatory. Dark gaps in the daily arcs are caused by cloud cover, whereas continuous bright tracks record glorious spells of sunny weather. Of course, in June, the Sun trails begin higher at the northern hemisphere's summer solstice. The trails sink lower in the sky as December's winter solstice approaches. Last year's autumn was one of the balmiest on record in the UK, as the many bright arcs in the lower part of this picture testify.