Astronomy Picture of the Day -- Solstice to Equinox Cubed

NASA ^ | Saturday, March 26, 2016 | (see photo credit)

[SunkenCiv]

Explanation: This 3 month long exposure packed the days from December 22, 2015 through March 20 into a box. Dubbed a solargraph, the unconventional, unfolded picture was recorded with a pinhole camera made from a cube-shaped container, its sides lined with photographic paper. Fixed to a single spot for the entire exposure, the simple camera recorded the Sun's path through Hungarian skies. Each day a glowing trail was burned into the photosensitive paper. From short and low, to long and high, the trails follow the progression from winter solstice to spring equinox. Of course, dark gaps in the daily sun trails are caused by cloud cover. Sunny days produce the more continuous bright tracks.

[SunkenCiv]

[Credit and Copyright: Olivér Nagy]

[SunkenCiv]

The Big One

join or quit list APoD 'blog post new APoD topic Astronomy Picture of the Day topic & keyword Astronomy Chat, Bloggers & keyword Science Chat, Bloggers & keyword NASA's APoD archive Calendar 1995-present APoD on your desktop

[NormsRevenge]

Cool! Looks like a data stream.. Or some pretty wild chemtrails.. ;-)

[zeestephen]

I don’t completely understand the relationship of the background photo to the “sun tracks.”

It appears there are two intersecting roads in the foreground.

Why aren’t there blurred images of vehicles or pedestrians that block our view of the house and the trees in the background?

[SunkenCiv]

:’)

[Prospero]

How small was the pinhole. I'm keenly aware of the pinhole effect, from personal experience. But even with the diminishing of ambient light to bare minimum, over such a period and with a penultimate object and source of natural light, it impresses me how little scattering occurred. The emulsion sensitivity must have been part of the story.

Well done.

[Robert A Cook PE]

You’re looking at a 24-hour exposure of the sun, with all of that sunlight only becoming a simple “stripe”.

Even a truck parked in front of the pinhole camera for an hour would “show” as a “dark spot” across the sun’s stripe for that day (one day’s declination angle is between each track) for that one hour.

[zeestephen]

Thanks, Mr. Cook, but I still don’t get it.

The photo is a three month exposure, not 24 hours.

And clouds permanently blot out parts of the “sun streaks,” so why wouldn’t a truck driving in front of the house permanently block out our view of the house?

Unless, that is not a road in front of the house, and for three months nothing actually blocked our view.