If you’re walking through Berlin in the evening and feel that the city suddenly seems even more atmospheric under the warm spring sky, there may soon be a very special reason for it. In just a few days, one of the rarest celestial spectacles of the year —the so-called “Blue Moon”— will appear over the capital. Despite its name, the moon won’t actually glow blue, but this astronomical event brings with it several unique features. On May 31, the second full moon within a calendar month will shine over Germany—a rare calendar phenomenon that occurs only about every two to three years .
The upcoming Blue Moon is also considered the smallest full moon of the entire year and will be located approximately 405,000 kilometers from Earth . The reason for this lies in the Moon’s orbit. Since the Moon does not orbit Earth in a perfect circle but rather in a slightly elliptical path, its distance from Earth is constantly changing. While so-called supermoons appear particularly close to Earth, the opposite is true for the upcoming Blue Moon: The Moon reaches nearly its greatest distance from Earth and therefore appears slightly smaller and less bright than ordinary full moons. Astronomically, this is also referred to as a “micromoon.”
Nevertheless, the difference will be barely visible to the naked eye. The moon will simply appear slightly more compact and subtle than during a supermoon. However, especially shortly after moonrise, the event can still look spectacular. Due to its low position on the horizon, the full moon often appears orange-gold and particularly atmospheric. The rare full moon could look especially impressive against Berlin backdrops such as the TV Tower, Tempelhofer Feld, or the Oberbaum Bridge .
The term “Blue Moon” often causes confusion, because the moon does not actually appear blue. Rather, it refers to the second full moon within a single calendar month. Because the lunar cycle lasts about 29.5 days, this phenomenon occurs only rarely. This is precisely where the well-known English idiom “Once in a blue moon” comes from—meaning something that happens very rarely.
It is also interesting to note that the Blue Moon in 2026 follows directly after a month that is already very moon-rich. A full moon appeared as early as May 1, which automatically makes the second full moon on May 31 a Blue Moon. In addition, bright planets such as Venus or Jupiter are often visible in the evening sky at the end of May, which could make the spectacle even more spectacular.
