Rare celestial spectacle fascinated observers in southern Hesse
On Sunday evening, stargazers in Darmstadt experienced a special spectacle: a total lunar eclipse, which was clearly visible over much of southern Hesse. The images taken at Darmstadt's Oberfeld (photos: Arthur Schönbein) impressively depict the eclipse – even though the view was initially obscured by thin, veiled clouds. Only later in the evening did the sky clear, allowing the moon, with its reddish hue, to become increasingly visible.
The moon was completely within Earth's umbra at sunrise. This phase is called totality and lasted about an hour. As the moon slowly rose higher in the evening twilight, it was intensely red, especially near the horizon. The reason: its light had to pass through the atmosphere on its way to Earth, which filtered it even more.
The fact that the Moon doesn't simply disappear during an eclipse, but instead appears in a characteristic red, is an effect of light refraction. The Earth's atmosphere acts like a filter. Sunlight is split into its different wavelengths as it enters the atmosphere. Short-wave blue light is scattered more strongly and escapes from the shadow cone, while the longer-wave red components are bent and directed toward the Earth's surface. This light reaches the Moon, causing it to glow reddish.
A total lunar eclipse only occurs during a full moon, when the sun, Earth, and moon are exactly aligned. Although the moon regularly crosses Earth's shadow, the exact alignment of Earth and the moon's orbit occurs only rarely—usually twice a year. However, the phenomenon is only visible in the hemisphere where the moon is above the horizon at that time. On Sunday, this was the case in Europe, Asia, and Africa.
For observers in Germany, patience is now a must: The next opportunity will be on August 28, 2026. However, only a partial lunar eclipse will be visible then – the impressive image of a completely red moon will remain a rarity until further notice.
(DARMSTADT – RED/as)
