"The Sickle was swinging bright above the shoulders of Bree-hill."
A footnote explains that the Sickle is the Hobbits’ name for the Plough or Great Bear. Also known as the Big Dipper
, this is a star constellation made up of seven stars that does indeed look more like a sickle, or a saucepan, than anything else. A sickle is a tool with a curved blade, used for cutting crops.
This is another very strong hint that Middle-earth is meant to be understood as a past or alternate version of our own world (see bookmark for page 209).