Sparkling spider webs
Early in the morning, when the sun chases the night’s shadows from
lawns, gardens, and meadows, the ground is full of sparkles. Dewdrops,
like tiny jewels, are everywhere. They glitter on spider webs, glisten
on leaves, and gleam on blades of grass.
But if the ground was dry the day before, and there was no rain during
the night, where did all the sparkling dewdrops come from?
Dew forms on still, clear nights when the air is warm and moist and the
ground is cool. When the sun goes down, leaves and grass and spider webs
and other things out in the open grow cool. As the moist air touches
them, it grows cool, too. Then, the molecules of water vapor in the air
rush together. They form tiny drops of water that coat the leaves,
grass, spider webs, and other things. These tiny drops slowly run
together and form the bigger drops of dew that greet the morning
sunshine.
You can make dew with your breath. When you are inside on a cold winter
day, blow your breath gently against a windowpane. A small, grayish
patch will form on the glass. Blow some more and tiny drops of water
will form. Blow again and the drops will begin to run together and make
bigger drops. This is how dew forms.
