Lisa Bundick, age 9, of Houston, Texas, for her question:

What does a halo around a star mean?

A halo in the sky may be a hazy ring around the moon or a star. Some people say that these halos have something to do with the weather. They claim that halos mean that we can expect rain. These weather forecasts may be partly right. Those halos are created way up in the air    in the atmosphere where all our weather events are born.

Sometimes the moisture in the air forms hazy mists. This moisture may be tiny wet droplets of foggy mist. High above the ground, where the air is much colder, those fine droplets often freeze into tiny crystals of ice. They too form hazy mists. Sometimes a thin, high mist veils the whole sky. The stars show through, but we see misty halos around them. When these mists are there, the air is filled with moisture    the sort of moisture used tc make rain. Sometimes, though not always, a halo around a star or the moon means that we can expect showers.