Today is the equinox
The Sun crosses the celestial equator heading north at 16:57 UT, marking
the northern hemisphere's first day of spring.
To celebrate, consider this remarkable image following the Sun's
yearly trek through planet Earth's sky, the first
exposed every day through the technique of
In fact, three analemma curves were captured using a
cylindrical pinhole camera
by daily making three, separate, one minute long
exposures for a year,
from March 1, 2013 to March 1, 2014,
on a single piece of black and white photographic paper.
daily exposures began
at 10:30, 12:00, and 13:30, CET
from a balcony looking south from the Kozanów district
in Wrocław, Poland.
That year's two equinoxes on March 20 and
, not the cross-over points,
along the figure-8
Apparent gaps in the curves are due to cloudy days.
Two solid lines at the lower left were both caused by a timer switch failure
that left the pinhole shutter open.