This article was automatically translated from the original Turkish version.
Ay eclipse is the phenomenon in which the Moon becomes completely or partially dark as a result of the Earth moving between the Sun and the Moon. This astronomical event is closely observed by people because it often produces striking and captivating visual effects. Lunar eclipses also provide scientists with opportunities to better understand the movements of celestial bodies.
A lunar eclipse is an astronomical event that occurs when the Sun, Earth and Moon align approximately in a straight line, causing the Earth to block sunlight from reaching the Moon partially or fully. Scientifically, this happens when the Moon enters the Earth’s shadow cone, particularly its umbra region. A lunar eclipse can only occur during afull moonphase.
How Does a Lunar Eclipse Occur?, NASA Video
A lunar eclipse occurs when the Sun, Earth and Moon align in a straight line. Sunlight is blocked by the Earth’s shadow, causing the Moon to darken. The Earth’s shadow consists of two regions: the penumbra (partial shadow) and the umbra (full shadow). The type of lunar eclipse depends on which of these shadow regions the Moon passes through:

【1】
Lunar eclipses occur when the Sun, Earth and Moon align, and this alignment can happen several times a year.
The Moon’s orbit is tilted by approximately 5° relative to Earth’s orbit. Therefore, an eclipse does not occur at every full moon, but only when the Moon passes very close to the Earth’s shadow cone.

【2】
Lunar eclipses have provided astronomers with important observation opportunities from ancient times to the present. In antiquity, celestial events were used in mythology and calendar calculations. In modern astronomy, lunar eclipses are of great importance for studying the composition of Earth’s atmosphere, observing changes on the Moon’s surface, and understanding motions within the Solar System.
Throughout history, lunar eclipses have had both psychological and cultural effects on people. In ancient civilizations, eclipses were interpreted as divine warnings or harbingers of disaster.
Cajochen, C., S. Altanay-Ekici, M. Münch, S. Frey, V. Knoblauch, and A. Wirz-Justice. "Evidence That the Lunar Cycle Influences Human Sleep." Current Biology 23, no. 15 (2013): 1485–1488.
Cermak, Alicia, and NASA Moon Team. "Eclipses and the Moon - NASA Science." NASA Science, February 14, 2025.https://science.nasa.gov/moon/eclipses/.
Espenak, Fred. "Lunar Eclipses for Beginners." Accessed March 22, 2025.https://www.mreclipse.com/Special/LEprimer.html.
Foster, R. G., and T. Roenneberg. "Human Responses to the Geophysical Daily, Annual and Lunar Cycles." Current Biology 18, no. 17 (2008): R784–R794.
Karttunen, H., P. Kröger, H. Oja, M. Poutanen, and K. J. Donner. Fundamental Astronomy. New York: Springer Science & Business Media, 2007.
NASA Eclipse Web Site. Accessed March 22, 2025.https://eclipse.gsfc.nasa.gov/.
NASA Video. "How Does a Lunar Eclipse Work?" YouTube, May 14, 2013.https://www.youtube.com/watch?v=mbT50-rppaU.
Topal, Selçuk. "Güneş ve Ay Tutulmaları Nasıl Gerçekleşir?" Bilim Genç. November 8, 2022.https://bilimgenc.tubitak.gov.tr/makale/gunes-ve-ay-tutulmalari-nasil-gerceklesir.
[1]
Yazar, Ögetay Kayalı. “Ay tutulması nedir? ne zaman olur? 2021 listesi - Evrim ağacı.” Evrim Ağacı, March 31, 2021. https://evrimagaci.org/ay-tutulmasi-nedir-ne-zaman-olur-2021-listesi-12966.
[2]
“Lunar Eclipses for Beginners.” Fred Espenak, n.d. https://www.mreclipse.com/Special/LEprimer.html.

What Is a Lunar Eclipse?
How Does a Lunar Eclipse Occur?
How Often Do Lunar Eclipses Occur?
Scientific Significance of Lunar Eclipses
The Impact of Lunar Eclipses on Humans