Planet Earth
International Astronomical Union WGSN

Shadow Observations

Sun and moon cast shadows. Everyone knows the principle of the sundial. But that the moon also casts shadows is less known and that this also works with Venus, even less.

In pre-scriptural cultures (4500 years ago and more), the shadows cast by the sun and moon were certainly observed much more than today. What was possible to find out about the seasons and the shape of our planet, we know from historical research.

In modern times, however, it is always worthwhile to prove with feasibility studies that the statements theoretically derived from historical research are really possible.

Let us therefore place ourselves at the naive level of knowledge of the people of that time and see experimentally whether we can also prove without the modern textbook knowledge,
a) that the Earth is a sphere,
b) that the (northern) summer is shorter than the the (northern) winter
c) that the rising points of the sun and moon on the horizon shift and in what way (where the solar and lunar turns are located on a given).

At Berlin Planetarium, the group AG Astronomiegeschichte (AGAG) im Planetarium am Insulaner, Berlin, assembles people interested in archaeoastronomy (archeologists, historians, professional and hobby-astronomers).