The simulation frames present the star sky of Athens for this night at half-hour steps. Small differences in object positions are to be expected when observing from other sites in Greece (up to one tenth of the map size for the most distant from Athens locations).
The border of the large circle defines the mathematical horizon (the sea level), i.e. there are not taken into account possible landscape irregularities. Its centre is the Zenith, the highest point on the sky exactly above us. The letters around indicate the four directions, North (N), East (E), South (S), and West (W).
Shown are objects visible to the naked eye. The circles representing stars and planets have sizes corresponding to their brightness. The constellations are drawn as well. When the Moon is above the horizon, its position is shown by an open circle.