Astronomy can be introduced in preschool as a preparation for the Great Lessons. In the first lesson , the universe's creation is introduced. Later, our solar system is introduced more fully. Many teachers introduce another story about our stars, including our sun and the formation of galaxies. This includes constellations and their names.
Constellations can be introduced to preschool children as a dot to dot activity. Older students can study star charts and observe constellations in the night sky without a telescope.
Wikipedia has a good timeline of the history of the universe, the Earth and people.
This is a free online traditional Navajo story about The Sun, Moon and Stars
Montessori for Everybody has nomenclature cards for parts of the sun.
Here are two books to check out at your local library:
Find the Constellations , by H.A. Rey
Advanced Skywatcing, the backyard astronomer's guide to starhopping and exploring the universe