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.
Image Credit & License: Cees Bassa (Netherlands Institute for Radio Astronomy)
What's happening to this Sun-crossing rocket?
The SpaceX Falcon 9 rocket, visible on the upper left, launched only about one minute before this amazing image was captured.
As it rose to low Earth orbit from Cape Canaveral, Florida, USA, in late May, the rocket became supersonic before it crossed the disk of the distant Sun -- from the perspective of the well-placed photographer.
The spacecraft's high speed caused bow-shaped compressed-air shockwaves to form across leading surfaces, with at least three visible even outside the Sun's disk because they refract sunlight.
The trailing exhaust caused turbulence visible on the lower right. None of this was damaging to the robotic Starlink 10-53 mission, which delivered 29 communications satellites to low Earth orbit as planned. And if that isn't amazing enough - the Sun had spots!
Image Credit & Copyright: John Winkopp (WAI Media)