Occasive Amplitude

Second place winner in the 2023 IAU OAE Astrophotography Contest, category Still images of sunrise and sunset locations over the year: Occasive Amplitude, by Marcella Giulia Pace.

Captured from Gatto Corvino village in Sicily, this composite showcases the Sun setting at various points over the sea from the winter to the summer solstice (2016–2017). The centre frame marks due west. As Earth orbits the Sun, the position of the setting (and rising) Sun changes from being northward of due west (east) in summer to southward of due west (east) in winter. During the equinoxes — when day and night are of equal length — the Sun rises directly in the east and sets directly in the west. The changing location of the Sun on the horizon is due to Earth’s axial tilt as it orbits the Sun. In temperate regions of Earth, the Sun’s height above the horizon at noon is at its highest and lowest points in the sky on the summer and winter solstices respectively.

Credit: Marcella Giulia Pace/IAU OAE (CC BY 4.0)