One autumn evening in Norfolk, William Cole wrote:

“The atmosphere with humid vapours flow,

And the pale moon displays her lunar bow.”

He felt it necessary to explain with a footnote: “See the Norfolk Chronicle of Nov. 17, 1799”. It was a reference that explained the unusual lunar feature.

In this more recent image, released on 18 October 2016, a moonbow is visible in the night sky above a field in the Coquet Valley in Northumberland, England (Ian Glendinning/AP)

These lunar bows occur when light reflected from the moon (rather than shining directly from the sun) is refracted through mist or rain suspended in the dimming atmosphere.
The German romantic painter Caspar David Friedrich (1774-1840) showed a moon bow in his Mountain Landscape that now hangs in the Folkwang Museum in Essen (Wikipedia)