Norwegian painter Knud Baade specialised in moody moonlit landscapes. His Scene From the Era of Norwegian Sagas (1850) shows a lonely figure, perhaps one of the legendary Nordic kings featured in the Old Norse sagas, holding a spear as he surveys a glowing cloudscape over choppy waters. The Moon is producing cloud iridescence as it shines through the edges of the icy upper reaches of a Cumulonimbus cloud. The iridescent colours result from moonlight bending, or diffracting, around the cloud’s particles. In our world, it would be rare for the Moon to be bright enough and the edge of a Cumulonimbus thin enough to produce as much iridescence as this – almost circling the Moon completely, which is when we’d describe it as a corona. Perhaps the Moon shone brighter in the era of Norwegian Sagas? Bright enough to pierce a storm cloud’s anvil and create a crown of light fit for a Nordic king.