Tonight’s wonder
A garden made by cold air
Hoar frost appears when water vapour becomes ice without first becoming liquid—a quiet shortcut from air to crystal.
On a still, clear night, a surface can cool below the temperature of the air around it. Water molecules settle there and arrange themselves into six-sided structures: needles, feathers, ferns, and tiny trees.
The word hoar means white or grey with age. Look closely, though, and the frost is less like grey hair than a forest inventing itself before breakfast.
Field note: Frost grows best when the air is moist, the wind is light, and the sky is clear enough for the ground to lose its warmth.