I have been doing a version of this lesson for several years. With older students, we usually add a writing element-their wish for the earth, a poem, something about earth day or recycling. You can make this as complicated or as simple as you like.
This year, I tried it with the 4 year old preschool students. They started by drawing dots all over black paper to create the stars.
They painted the back of a plate with white, green and blue paint. Then pressed it onto the black paper, gave a twist and voila! a print of the earth.