In the night from August 30 to 31 there is something special to marvel at in the sky in Germany: the supermoon and at the same time”Blue Moon”. Supermoon is the name for a full moon that appears larger and brighter than normal because the earth and the moon come especially close to each other. The moon is then only about 356,000 kilometers away from the earth, otherwise the distance can be up to 406,000 kilometers. The difference in distance is due to the fact that the moon orbits the Earth not in a circle, but in an ellipse, i.e. it has a slightly egg-shaped orbit.
This event is called a “blue moon” when it occurs twice in one month. And that is the case this August, because there has already been a supermoon on August 1 as well. Of course, the moon is not really blue, but the name comes from the English saying: “Once in a blue moon”. It means a very rare event, in German one would say: “Das kommt nur alle Jubeljahre vor”—thus if there is an anniversary.
If you want to see the rare celestial phenomenon, you need a sky that is not covered by clouds. In Tübingen, you should watch the moon rise at 8:22 p.m. on August 30: Although the moon is then only a 98 percent full moon, it appears largest directly above the horizon. The actual supermoon is reached on August 31 at 3.37 o’clock in the night.
The Planetarium Hamburg has put a nice explanatory video online: Zweimal Supermond: Der
August 2023 ist die Zeit des „Blue Moon”—[GEOLINO]
Supermond am 1. August 2023 kurz nach Mondaufgang – der Vollmond erscheint besonders groß und hell. Man kann sehr gut die Kraterlandschaft auf dem Mond erkennen. Foto: tünews INTERNATIONAL / Michael Seifert