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Credit & Copyright: Cees Bassa
(Netherlands Institute for Radio Astronomy)
Explanation:
What if you could see the entire sky -- all at once -- for an entire year?
That, very nearly, is what is pictured here.
Every 15 seconds during 2025, an
all-sky camera took an image of the sky over the
Netherlands.
Central
columns from these images were then aligned
and combined to create the featured
keogram, with January at the top,
December at the bottom,
and the middle of the night
running vertically just left of center.
What do we see?
Most obviously, the daytime
sky is mostly blue, while the nighttime sky is mostly black.
The twelve
light bands
crossing the night sky are caused by the
glow of the
Moon.
The thinnest
part
of the black hourglass shape occurs during the summer
solstice, like
today,
when days are the longest, while the thickest part occurs at the winter
solstice.
Equinoxes can also be located in the keogram, for example
the northern-spring
equinox from one year ago is about
three-quarters of the way up.
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January February March April May June |
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: solstice
Publications with words: solstice
See also: