Cees BassaHappy new year! Another year means another year-long keogram! Every 15 seconds throughout 2022, my trusty all-sky camera took a picture of the sky above the Netherlands. Combining these 2.1 million images into a year-long keogram reveals this picture, which shows the length of the night change throughout the year (the hourglass shape), when the Moon was visible at night (diagonal bands), and the Sun higher in the sky during summer, as well as lots and lots of clouds passing overhead.
dr 🛠️🛰️📡🎧
@cgbassa It's interesting that the hourglass isn't symmetrical the "daytime" dimension, although the entire hourglass seems rotationally symmetric.
In the first half of the year, it looks like sunrise changes more rapidly whereas in the second half it's sunset that does.
I've seen that in sunrise/sunset times directly as well, but I don't remember why it is.
