Sunlight charges the earth

Sunsets on the moon

Yesterday the moon went through its last quarter and therefore now shows itself as a sickle. So it is night on more than half of the lunar hemisphere facing us. Only the crescent-shaped part is still bathed in sunlight. It will get narrower and narrower until the moon reaches its new moon phase on Friday.

When the sun goes down on the moon, it creates fascinating interplay of light and shadow. The moon has no atmosphere to break the sunlight. Therefore the shadows are sharply defined. But the shadows on the side of the moon facing us are not quite as dark as on the back of the moon, because they are still brightened by the indirect light of the "earth glow", sunlight that our earth reflects into space.

Sunsets on the moon are slow. On earth, only a few minutes pass from the moment the sun ball touches the horizon until it can no longer be seen. The moon rotates slower than the earth. A sunset there lasts almost an hour.

On the airless moon, the sky remains dark even at sunset. However, the sun may turn a little reddish as it approaches the horizon. The solar radiation charges the dusty lunar soil electrically, so that part of the dust practically floats above the surface. If sunlight falls through the dust, the dust can appear slightly reddish.